Trevor gives you good advice Leslie. You should also play around with the
toe-in of your speakers. Specifically toe them out so they point straight
ahead as opposed to pointing straight at the listener and then listen and
try gradually toeing them in a little bit at a time. You may find a balance
there that is more pleasing. I have never heard a Mistral before, but heard
good things. I have heard Spendor and would not characterize them as overly
bright. More Englishly polite and voiced for long fatigue free listening.
They are built to a high standard.


"Spongebob" wrote in message
...
I am considering going to a tube amp, after 25 years of solid state
amps. (Specifically, it is a conrad-johnson, but my question is general.)
I have read comments through the years about the problems tube amps
have ("always in the shop", etc.). Is this a reality? I live in a town
with no tube amp dealers, and would need to send it back to the
manufacturer
if it fails. Are my knees quaking for no good reason?

By the way, I don't consider the need to bias the tubes a problem. I would
be grateful for any feedback.
--Leslie

On Thu, 27 May 2004 21:25:39 GMT, "Trevor Wilson"
wrote:


"Spongebob" wrote in message
...
I am considering going to a tube amp, after 25 years of solid state
amps. (Specifically, it is a conrad-johnson, but my question is general.)
I have read comments through the years about the problems tube amps
have ("always in the shop", etc.). Is this a reality?

**It can be. Ask an ARC M300, D250 owner sometime. A badly designed tube
amp, can be a disaster. A properly designed one can offer very high levels
of reliability. With one big caveat: ALL tube amps gradually wear out.

You mean all TUBES gradually wear out. There's a pretty easy solution
to that that the owner can do without sending the amp in for repair.
It's called "replacing the tubes". This is a little easier for the
average consumer than when a power transistor dies.

Of course, *all* amps gradually wear out, especially internal
components like capacators.

From the first minute it is switched on.

Well, transistors start dying from the first minute that an SS amp is
swiched on. Of course, the time frame is much longer, but when they
go, that's it. Time to send it to the shop.

Typically, with around 2 hours per day
of listening, you can expect around 6 months life from output tubes and
around 2 years from low level tubes. Many tube amp lovers deny this, but is
is simple enough to prove. Buiy two sets of tubes. Replace the outputs after
3 months, then 6 months. When you can hear a difference, the tubes are worn.

I live in a town
with no tube amp dealers, and would need to send it back to the
manufacturer
if it fails. Are my knees quaking for no good reason?

**Tube amps do not travel well.

I don't know why not.

Of course, you don't have to send it back to the manufacturer just to
replace tubes.

By the way, I don't consider the need to bias the tubes a problem. I would
be grateful for any feedback.

**Why do you want a tube amp?

Maybe he wants to try something new? Maybe he heard a tube amp that
sounded really good to him? Maybe he likes the look?

I'll have to say that I love my old 40 year old Fisher X202. It sounds
great (and plays with a lot more authority than most 40 wpc SS amps),
looks cool and is the ****. Of course, it uses output tubes that
aren't all that common anymore, so that's a drawback for that
particular amp.

On Thu, 27 May 2004 23:03:22 GMT, "Trevor Wilson"
wrote:

4) I have had my present system turned off for two months, because I
don't
enjoy listening to it. It's time for a change!

**It may well be. DO not discount transistors, based on one experience and
heresay. Transistor amplifiers can offer serious and undeniable advantages
over tube amps. PROVIDED you choose carefully. I suggest you try to listen
to a wide range of different amps, with your speakers, before committing to
a product, based on what you've read about.

You can turn this around and say that you shouldn't discount tube
amps, as Trevor is wont to do, simply because *some* of them might not
be well designed.

Also, she *has* heard tubes that she has enjoyed.

And sorry for calling you a he in my previous post, Leslie. I think it
was the spongebob name that misled me...

"dave weil" wrote in message
...
On Thu, 27 May 2004 21:25:39 GMT, "Trevor Wilson"
wrote:


"Spongebob" wrote in message
...
I am considering going to a tube amp, after 25 years of solid state
amps. (Specifically, it is a conrad-johnson, but my question is
general.)
I have read comments through the years about the problems tube amps
have ("always in the shop", etc.). Is this a reality?

**It can be. Ask an ARC M300, D250 owner sometime. A badly designed tube
amp, can be a disaster. A properly designed one can offer very high
levels
of reliability. With one big caveat: ALL tube amps gradually wear out.

You mean all TUBES gradually wear out.

**True.

There's a pretty easy solution
to that that the owner can do without sending the amp in for repair.

**Also true.

It's called "replacing the tubes". This is a little easier for the
average consumer than when a power transistor dies.

**Points:
*Transistors are VERY reliable. They do not wear out (for the most part). I
have a Marantz Model Eighteen on my workbench. It is used every day of the
working week. The output devices (on one channel) have failed exactly once,
in 35 years. The only other failure has been (yes, you guessed it) the CRO
tube. This kind of reliability, in a well designed SS product is normal.
*A set of output tubes in a D250 amp may run to a couple of thousand
Dollars. A set of output devices in a similarly priced SS amp (including
labour to fit) would be significantly less. At worst, maybe a Grand.
*Have you ever wondered why no tube amp manufacturer guarantees his/her
product for more than 90 days and yet, premium SS amps have guarantees
between 5 and 20 YEARS? Do I need to spell out the commercial realities of
the decisions?


Of course, *all* amps gradually wear out, especially internal
components like capacators.

**Absolutely. Capacitors fail when subjected to high temperatures. Wanna
speculate on which kind of amp runs hotter: SS or tube?


From the first minute it is switched on.

Well, transistors start dying from the first minute that an SS amp is
swiched on. Of course, the time frame is much longer, but when they
go, that's it. Time to send it to the shop.

**Back in the 1970s, RCA published a paper which outlined the life-span of
transistors. The life-span was rated as hot/cold cycles. This because, if a
transistor is operated (within reasonable limts) at a constant temperature,
its lifespan will be essentially infinite (assuming it has been manufactured
correctly). Anyway, back in the 70s, RCA determined that plastic pack
devices enjoyed a life-span in the order of 10^4 hot/cold cycles, aluminium
cased devices, 10^5 hot/cold cycles and steel/copper cased devices, in
excess of 10^6 hot/cold cycles. 10^6 hot/cold cycles is essentially
infinite. With 30 odd years of materials technology to draw on, it is
reasonable to expect that these figures have been improved upon
significantly.


Typically, with around 2 hours per day
of listening, you can expect around 6 months life from output tubes and
around 2 years from low level tubes. Many tube amp lovers deny this, but
is
is simple enough to prove. Buiy two sets of tubes. Replace the outputs
after
3 months, then 6 months. When you can hear a difference, the tubes are
worn.

I live in a town
with no tube amp dealers, and would need to send it back to the
manufacturer
if it fails. Are my knees quaking for no good reason?

**Tube amps do not travel well.

I don't know why not.

**The tubes are fragile.


Of course, you don't have to send it back to the manufacturer just to
replace tubes.

**Quite true. However, chances are you won't need to send a transistor amp
back at all. I gotta say, however, that I repair a lot of tube amps. In the
majority of cases where a (output) tube goes belly-up, something else fails
as well. This will require tech for repair.


By the way, I don't consider the need to bias the tubes a problem. I
would
be grateful for any feedback.

**Why do you want a tube amp?

Maybe he wants to try something new? Maybe he heard a tube amp that
sounded really good to him? Maybe he likes the look?

**Maybe she is assuming that all transistor amps sound the same. Worse,
maybe she is assuming that all tube amps sound the same. There are bad (and
good) examples of both kinds of amps.


I'll have to say that I love my old 40 year old Fisher X202. It sounds
great (and plays with a lot more authority than most 40 wpc SS amps),
looks cool and is the ****. Of course, it uses output tubes that
aren't all that common anymore, so that's a drawback for that
particular amp.

**There's that too.


--
Trevor Wilson
www.rageaudio.com.au

"dave weil" wrote in message
...
On Thu, 27 May 2004 23:03:22 GMT, "Trevor Wilson"
wrote:

4) I have had my present system turned off for two months, because I
don't
enjoy listening to it. It's time for a change!

**It may well be. DO not discount transistors, based on one experience
and
heresay. Transistor amplifiers can offer serious and undeniable
advantages
over tube amps. PROVIDED you choose carefully. I suggest you try to
listen
to a wide range of different amps, with your speakers, before committing
to
a product, based on what you've read about.

You can turn this around and say that you shouldn't discount tube
amps, as Trevor is wont to do, simply because *some* of them might not
be well designed.

**Absolutely. One needs only do one's homework to establish what is one of
the better products, before purchase.


Also, she *has* heard tubes that she has enjoyed.

**I've heard tube amps I enjoy, also. However, I can get the same enjoyment
for less cash, with a decent SS amp.


--
Trevor Wilson
www.rageaudio.com.au

Spongebob wrote:
I am considering going to a tube amp, after 25 years of solid state
amps. (Specifically, it is a conrad-johnson, but my question is
general.) I have read comments through the years about the problems
tube amps have ("always in the shop", etc.). Is this a reality? I
live in a town with no tube amp dealers, and would need to send it
back to the manufacturer if it fails. Are my knees quaking for no
good reason?

In the days when tubes were all we had, the equipment itself was acceptably
reliable by then-current standards. If you used the amp daily, the tubes
showed measurable degradation in 3 months to several years, depending on the
design of the amp. Tubes often lasted from 3 to 5 years or more, before
absolutely requiring replacement.

Spongebob wrote:

I think I want a tube amp because:
1) I have Spendor SP1/2 speakers, which are known for being "laid
back", and not bright. For some reason, I find listening to them
fatiguing with my English LFD Mistral electronics. I find the upper
mid range annoying. Not as bad as fingernails on a blackboard, but
like it, in a mild form. I have never heard the Mistral described as
anything buy "musical", never bright, so I'm going to blame the
transistors.

Why not blame the speakers, their placement, or room acoustics?

2) I am a woman, and we apparently have more sensitive
hearing in the upper mid range than men. I have read that in audio
stores, women prefer the sound of tubes over solid state, while men
prefer a brighter sound.

People will say the darndest things. Tubed amps sound like solid state amps
with some kind of effects box attached. The exact nature of this inherent
effects box feature of a given tubed amp/speaker combination will be
more-or-less randomly chosen. In an unbiased test you might like the effect
better or worse, but you will probably try to convince yourself that you
like it better as you spend more and more money for the tubed amp.

There really is no such thing any more as an good, inexpensive tubed amp
unless you get really lucky.

3) The electronics I had before getting the
Mistral setup included a Dynaco PAS-1, which as you know, is a tube
preamp. The sound was never tiring or overly bright, and I didn't
tire of listening to it.

A little history. AFAIK, there was no such thing in any Dyna catalog as a
PAS-1. There is such a thing as two PAM-1s and a DSC-1 stereo adaptor, which
is sometimes erroneously called a PAS-1. This was used with either a Dyna
power amp for power, or a PS-1 power supply. Odds are pretty good you were
using this with a Dyna power amp, which then contributed to the overall
sound.

4) I have had my present system turned off
for two months, because I don't enjoy listening to it. It's time for
a change!

Something as simple as toeing in the speakers, or a area run on a wood floor
could make the difference. If you soften up the acoustics of your room
within reason, every piece of audio gear you ever bring into the room can
possibly benefit.

Hi, Leslie.

I am currently operating 3 McIntosh MC75's and one MC240 in my Library. All
are somewhere around 30 years old. The 2540 was a dealer's amplifier since
new, used to demo loudspeaksers. It still has McIntosh branded output and
small signal tubes. I have replaced the output tubes in my MC75's...not
because any of them failed, but because after all those years of service, a
failure could happen at any time.

No, these amplifiers are not turned on every day. But they have been installed
and in service for more than 5 years.

And they sound just like, exactly like the McIntosh solid state amplifiers I
have in my Family room, one two years old and one about 25 years old.

Yup. Try re-positioning your speakers and adding some absorption in their
first reflection boundrys.

Regards

"Trevor Wilson" wrote

ALL tube amps gradually wear out. From the first
minute it is switched on. Typically, with around 2 hours
per day of listening, you can expect around 6 months
life from output tubes and around 2 years from low
level tubes.

Mmmm... 2 hrs. X 180 (6 mo. X 2hrs.) = 360 hrs.
That's 15 days @ 24hrs. = total hrs. tube life.

What tube power amp manufactures and model
numbers are you specifically referring to, empirical
experience?

"2 years from low level tubes"... 1,440 hrs. or 60 days.
What tube models (6DJ8/6922, 12AX7, etc) numbers
are you specifically referring to, empirical experience?

"Spongebob" wrote

I am considering going to a tube amp, after 25 years
of solid state amps. (Specifically, it is a conrad-johnson,
but my question is general.) I have read comments
through the years about the problems tube amps
have ("always in the shop", etc.). Is this a reality?

Conrad-Johnson has been in business for more
than 20 years. They haven’t survived, with a good
reputation, because they produced faulty products.


I live in a town with no tube amp dealers, and would
need to send it back to the manufacturer if it fails. Are
my knees quaking for no good reason?

Certainly power tubes will be limited to less than
2,000 hrs. For most people that’s several years of
use. Some amps require periodic manual biasing
of the tubes for longest life. This requires the use of
a handheld meter to reset. Others are auto-biasing.
The price to re-tube a power amp can put some
people off. Re-tubing of 6550/KT88/KT90/KT100, for
example, can be expensive. The cost can range from
$25 to $100 per tube.

On Fri, 28 May 2004 07:18:56 -0400, "Arny Krueger"
wrote:

Spongebob wrote:

I think I want a tube amp because:
1) I have Spendor SP1/2 speakers, which are known for being "laid
back", and not bright. For some reason, I find listening to them
fatiguing with my English LFD Mistral electronics. I find the upper
mid range annoying. Not as bad as fingernails on a blackboard, but
like it, in a mild form. I have never heard the Mistral described as
anything buy "musical", never bright, so I'm going to blame the
transistors.

Why not blame the speakers, their placement, or room acoustics?

2) I am a woman, and we apparently have more sensitive
hearing in the upper mid range than men. I have read that in audio
stores, women prefer the sound of tubes over solid state, while men
prefer a brighter sound.

People will say the darndest things. Tubed amps sound like solid state amps
with some kind of effects box attached. The exact nature of this inherent
effects box feature of a given tubed amp/speaker combination will be
more-or-less randomly chosen. In an unbiased test you might like the effect
better or worse, but you will probably try to convince yourself that you
like it better as you spend more and more money for the tubed amp.

There really is no such thing any more as an good, inexpensive tubed amp
unless you get really lucky.

3) The electronics I had before getting the
Mistral setup included a Dynaco PAS-1, which as you know, is a tube
preamp. The sound was never tiring or overly bright, and I didn't
tire of listening to it.

A little history. AFAIK, there was no such thing in any Dyna catalog as a
PAS-1. There is such a thing as two PAM-1s and a DSC-1 stereo adaptor, which
is sometimes erroneously called a PAS-1. This was used with either a Dyna
power amp for power, or a PS-1 power supply. Odds are pretty good you were
using this with a Dyna power amp, which then contributed to the overall
sound.

No, odds are that she was using a PAS-2 or 3 and just typoed the name.
Of course, she might not have known she was using a MONO preamp with a
stereo amp, right Arnold?

4) I have had my present system turned off
for two months, because I don't enjoy listening to it. It's time for
a change!

Something as simple as toeing in the speakers, or a area run on a wood floor
could make the difference. If you soften up the acoustics of your room
within reason, every piece of audio gear you ever bring into the room can
possibly benefit.

You guys will struggle until the sun goes down to find a reason why
she shouldn't get what turns her on.

On Fri, 28 May 2004 05:54:59 GMT, "Trevor Wilson"
wrote:


"dave weil" wrote in message
.. .
On Thu, 27 May 2004 21:25:39 GMT, "Trevor Wilson"
wrote:


"Spongebob" wrote in message
...
I am considering going to a tube amp, after 25 years of solid state
amps. (Specifically, it is a conrad-johnson, but my question is
general.)
I have read comments through the years about the problems tube amps
have ("always in the shop", etc.). Is this a reality?

**It can be. Ask an ARC M300, D250 owner sometime. A badly designed tube
amp, can be a disaster. A properly designed one can offer very high
levels
of reliability. With one big caveat: ALL tube amps gradually wear out.

You mean all TUBES gradually wear out.

**True.

There's a pretty easy solution
to that that the owner can do without sending the amp in for repair.

**Also true.

It's called "replacing the tubes". This is a little easier for the
average consumer than when a power transistor dies.

**Points:
*Transistors are VERY reliable. They do not wear out (for the most part).

That's right. They just flash out.

I have a Marantz Model Eighteen on my workbench. It is used every day of the
working week. The output devices (on one channel) have failed exactly once,
in 35 years. The only other failure has been (yes, you guessed it) the CRO
tube.

And I've had several SS failures - one was an SAE 50 watt amp and one
was a B&K 4400 250 watt monoblock. I've seen the repair departments of
SS manufacturers and there is plenty of work for them.

This kind of reliability, in a well designed SS product is normal.

I don't doubt that SS amps are more reliable, especially if you
consider replacing tubes a "repair instance".

*A set of output tubes in a D250 amp may run to a couple of thousand
Dollars. A set of output devices in a similarly priced SS amp (including
labour to fit) would be significantly less. At worst, maybe a Grand.

Plus service charges.

*Have you ever wondered why no tube amp manufacturer guarantees his/her
product for more than 90 days and yet, premium SS amps have guarantees
between 5 and 20 YEARS? Do I need to spell out the commercial realities of
the decisions?


Of course, *all* amps gradually wear out, especially internal
components like capacators.

**Absolutely. Capacitors fail when subjected to high temperatures. Wanna
speculate on which kind of amp runs hotter: SS or tube?

Capacators also fail for other reasons as well, including age.

From the first minute it is switched on.

Well, transistors start dying from the first minute that an SS amp is
swiched on. Of course, the time frame is much longer, but when they
go, that's it. Time to send it to the shop.

**Back in the 1970s, RCA published a paper which outlined the life-span of
transistors. The life-span was rated as hot/cold cycles. This because, if a
transistor is operated (within reasonable limts) at a constant temperature,
its lifespan will be essentially infinite (assuming it has been manufactured
correctly). Anyway, back in the 70s, RCA determined that plastic pack
devices enjoyed a life-span in the order of 10^4 hot/cold cycles, aluminium
cased devices, 10^5 hot/cold cycles and steel/copper cased devices, in
excess of 10^6 hot/cold cycles. 10^6 hot/cold cycles is essentially
infinite. With 30 odd years of materials technology to draw on, it is
reasonable to expect that these figures have been improved upon
significantly.

That didn't stop me from having two failures in a couple of years.
Remember, it's not just output devices that can fail either.

Typically, with around 2 hours per day
of listening, you can expect around 6 months life from output tubes and
around 2 years from low level tubes. Many tube amp lovers deny this, but
is
is simple enough to prove. Buiy two sets of tubes. Replace the outputs
after
3 months, then 6 months. When you can hear a difference, the tubes are
worn.

I live in a town
with no tube amp dealers, and would need to send it back to the
manufacturer
if it fails. Are my knees quaking for no good reason?

**Tube amps do not travel well.

I don't know why not.

**The tubes are fragile.

Are you telling me that you can't pack tubes properly? GMAB. Yeah, if
you leave the tubes IN THE AMP, you're likely to break them.

Of course, you don't have to send it back to the manufacturer just to
replace tubes.

**Quite true. However, chances are you won't need to send a transistor amp
back at all. I gotta say, however, that I repair a lot of tube amps. In the
majority of cases where a (output) tube goes belly-up, something else fails
as well. This will require tech for repair.

That's true indeed. That's why you try to replace them before they go
belly up. With tubes, if you wait until failure, you've only got
yourself to blame. Most times, tubes will give you an indication that
something is wrong (not always though). Transistors just go pffffst!

By the way, I don't consider the need to bias the tubes a problem. I
would
be grateful for any feedback.

**Why do you want a tube amp?

Maybe he wants to try something new? Maybe he heard a tube amp that
sounded really good to him? Maybe he likes the look?

**Maybe she is assuming that all transistor amps sound the same.

I think that you're projecting (although that's what the SS nazis want
you to think anyway, right?)

It sounded to me (and yes, I'm projecting just like you) that she
wants a change and has heard some tube gear that she likes.

Worse,
maybe she is assuming that all tube amps sound the same. There are bad (and
good) examples of both kinds of amps.

Agreed. So why tell her that tube is BADDDDDDD?

I'll have to say that I love my old 40 year old Fisher X202. It sounds
great (and plays with a lot more authority than most 40 wpc SS amps),
looks cool and is the ****. Of course, it uses output tubes that
aren't all that common anymore, so that's a drawback for that
particular amp.

**There's that too.

Fortunately, I haven't had to replace them yet. I won't like that
because they have a matched quad of RCA NOSes.

On Fri, 28 May 2004 05:58:36 GMT, "Trevor Wilson"
wrote:


"dave weil" wrote in message
.. .
On Thu, 27 May 2004 23:03:22 GMT, "Trevor Wilson"
wrote:

4) I have had my present system turned off for two months, because I
don't
enjoy listening to it. It's time for a change!

**It may well be. DO not discount transistors, based on one experience
and
heresay. Transistor amplifiers can offer serious and undeniable
advantages
over tube amps. PROVIDED you choose carefully. I suggest you try to
listen
to a wide range of different amps, with your speakers, before committing
to
a product, based on what you've read about.

You can turn this around and say that you shouldn't discount tube
amps, as Trevor is wont to do, simply because *some* of them might not
be well designed.

**Absolutely. One needs only do one's homework to establish what is one of
the better products, before purchase.


Also, she *has* heard tubes that she has enjoyed.

**I've heard tube amps I enjoy, also. However, I can get the same enjoyment
for less cash, with a decent SS amp.

Not if you like the idea of having a tube amp. I suspect that for you,
it'd be like being in prison. For me, I like the idea of the Fisher in
the bedroom (except for the dead of summer chuckle.

BTW, as you know, I have a Denon AVR2800 in the main system, but only
because it's an AV system. I get far more enjoyment listening to the
Fisher, but that's not a diss of the Denon per se. I ran the Fisher as
my main amp for almost a year in the living room, so it's not a
function of the way I'm using it right now. Of course, I also had a
Mesa Baron for several months as well - talk about an amp that even a
SS maven such as yourself could love. Built like a tank...looks
industrially cool...

Now I need to get one of my Dynaco MK3 monoblock back in service (yes,
that's a failure that I can talk about - one tube started to glow
cherry red and I took it out of service - it's sitting right next to
the B&K monoblock g).

(RCGRND) said:

Hi, Leslie.

I am currently operating 3 McIntosh MC75's and one MC240 in my Library. All
are somewhere around 30 years old. The 2540 was a dealer's amplifier since
new, used to demo loudspeaksers. It still has McIntosh branded output and
small signal tubes. I have replaced the output tubes in my MC75's...not
because any of them failed, but because after all those years of service, a
failure could happen at any time.

No, these amplifiers are not turned on every day. But they have been installed
and in service for more than 5 years.

And they sound just like, exactly like the McIntosh solid state amplifiers I
have in my Family room, one two years old and one about 25 years old.

Yup. Try re-positioning your speakers and adding some absorption in their
first reflection boundrys.

Can I hear a big, fat AMEN!!!!!! for this post!

Hi Roger, nice to see you back on the board!

--
Sander deWaal
Vacuum Audio Consultancy

Gentlemen,
Thank you all sincerely for your thoughtful answers. The knowledge on
newsgoups is amazing. I'm not afraid to buy a tube amp now.
--Leslie

"Powell" wrote in message
...

"Trevor Wilson" wrote

ALL tube amps gradually wear out. From the first
minute it is switched on. Typically, with around 2 hours
per day of listening, you can expect around 6 months
life from output tubes and around 2 years from low
level tubes.

Mmmm... 2 hrs. X 180 (6 mo. X 2hrs.) = 360 hrs.
That's 15 days @ 24hrs. = total hrs. tube life.

What tube power amp manufactures and model
numbers are you specifically referring to, empirical
experience?

**The first time I challenged a tube amp owner to this test, was with an ARC
D115. He found a barely perceptible difference @ 3 months. By 6 months, the
new tubes easily sounded audibly better.


"2 years from low level tubes"... 1,440 hrs. or 60 days.
What tube models (6DJ8/6922, 12AX7, etc) numbers
are you specifically referring to, empirical experience?

**I cut my teeth on tubes. I've been servicing tube amps, since my younger
days (age 16). In those days, I pretty much exclusively serviced musical
instrument amplification. Two amps stand out in my memory. A Wasp (New
Zealand built) amp, using 4 X KT88 tubes. The other was a Marshall head,
using 6 X 6L6 tubes. Both amps ened up on my bench, every year, almost to
the day. Both amps ran the output tubes quite conservatively and were highly
regarded in their day. Both amps showed a serious power drop, purely through
emission fall of around 30% within that year. Naturally, distortion had
risen at the same time. In an audiophile setup, these performance drops
would be easily audible, by serious listeners.

Later on, I went to work for our overseas telecommunications body. Tubes
were still in use, in couple of areas. Naturally, in high power AM
transmission, the Tasman cable and, remarkably, in a thing known as 'TASI'
(Time And Speech Interpolation system). This nifty gadget occupied several
rack bays and effectively doubled the capacity of the Tasman undersea cable,
by placing fragments of speech into fragments of silence, during a telephone
conversation. Back in the 1960s, it was amazing technology. It was almost
completely a tubed device. It also required three, full time techs, to keep
it operational. Tube changes were an HOURLY fact of life. Each tube averaged
around 2,000 hours of life. Naturally, some lasted longer, some not so long.


--
Trevor Wilson
www.rageaudio.com.au

Sander said:

(RCGRND) said:

Hi, Leslie.

I am currently operating 3 McIntosh MC75's and one MC240 in my Library. All
are somewhere around 30 years old. The 2540 was a dealer's amplifier since
new, used to demo loudspeaksers. It still has McIntosh branded output and
small signal tubes. I have replaced the output tubes in my MC75's...not
because any of them failed, but because after all those years of service, a
failure could happen at any time.

No, these amplifiers are not turned on every day. But they have been
installed
and in service for more than 5 years.

And they sound just like, exactly like the McIntosh solid state amplifiers I
have in my Family room, one two years old and one about 25 years old.

Yup. Try re-positioning your speakers and adding some absorption in their
first reflection boundrys.

Can I hear a big, fat AMEN!!!!!! for this post!

Hi Roger, nice to see you back on the board!

Seconded! I almost wet myself when I saw someone mention MC75s and MC240s
here!

By the way, I just bought a lot of 20 7189s on e-bay. I guess that means I've
been sucked in.

Boon

Leslie said:

Gentlemen,
Thank you all sincerely for your thoughtful answers. The knowledge on
newsgoups is amazing. I'm not afraid to buy a tube amp now.
--Leslie


I'm sorry I came into this late, Leslie, but you and I have a lot in common.
;-)

I own Spendors (SP100s), and I've been running them with a LFD Mistral for the
last three years. Although I've experienced none of the annoying
characteristics you've complained about, I did need something more. I've
recently found the answer with a 1963 Scott LK-48 integrated tube amp with the
rare chocolate brown faceplate, all lovingly and painstakingly restored, piece
by piece, to mint condition. And it cost me less than one-fifth of what I paid
for my cartridge alone.

Don't be afraid of a tube amp...it may change your life!

Boon

"Trevor Wilson" wrote

ALL tube amps gradually wear out. From the first
minute it is switched on. Typically, with around 2 hours
per day of listening, you can expect around 6 months
life from output tubes and around 2 years from low
level tubes.

Mmmm... 2 hrs. X 180 (6 mo. X 2hrs.) = 360 hrs.
That's 15 days @ 24hrs. = total hrs. tube life.

What tube power amp manufactures and model
numbers are you specifically referring to, empirical
experience?

**The first time I challenged a tube amp owner to this
test, was with an ARC D115. He found a barely perceptible
difference @ 3 months. By 6 months, the new tubes easily
sounded audibly better.

After 6 months was the amp re-biased before a
comparison was made with new tubes? How did
you know the user only had 360 hrs. on the tubes?
Was this D115 an original or MKII


"2 years from low level tubes"... 1,440 hrs. or 60 days.
What tube models (6DJ8/6922, 12AX7, etc) numbers
are you specifically referring to, empirical experience?

**I cut my teeth on tubes. I've been servicing tube amps, since my younger
days (age 16). In those days, I pretty much exclusively serviced musical
instrument amplification. Two amps stand out in my memory. A Wasp (New
Zealand built) amp, using 4 X KT88 tubes. The other was a Marshall head,
using 6 X 6L6 tubes. Both amps ened up on my bench, every year, almost to
the day. Both amps ran the output tubes quite conservatively and were
highly
regarded in their day. Both amps showed a serious power drop, purely
through
emission fall of around 30% within that year. Naturally, distortion had
risen at the same time. In an audiophile setup, these performance drops
would be easily audible, by serious listeners.

Later on, I went to work for our overseas telecommunications body. Tubes
were still in use, in couple of areas. Naturally, in high power AM
transmission, the Tasman cable and, remarkably, in a thing known as 'TASI'
(Time And Speech Interpolation system). This nifty gadget occupied several
rack bays and effectively doubled the capacity of the Tasman undersea
cable,
by placing fragments of speech into fragments of silence, during a
telephone
conversation. Back in the 1960s, it was amazing technology. It was almost
completely a tubed device. It also required three, full time techs, to
keep
it operational. Tube changes were an HOURLY fact of life. Each tube
averaged
around 2,000 hours of life. Naturally, some lasted longer, some not so
long.

In grad school I was fortunate to have a retired military
instructor who has worked on a UNIVAC style computer
in the 40's. The guts of the computer covered an entire
floor, as I recall, and had several thousand tubes
(something like 16,000). It was designed for mathematical
computations in ballistics research and rarely operated for
more than half an hour at a time. The majority of all the
technician’s time was spent tracking down failed tubes in
preparation for another run.

"Powell" wrote in message
...

"Trevor Wilson" wrote

ALL tube amps gradually wear out. From the first
minute it is switched on. Typically, with around 2 hours
per day of listening, you can expect around 6 months
life from output tubes and around 2 years from low
level tubes.

Mmmm... 2 hrs. X 180 (6 mo. X 2hrs.) = 360 hrs.
That's 15 days @ 24hrs. = total hrs. tube life.

What tube power amp manufactures and model
numbers are you specifically referring to, empirical
experience?

**The first time I challenged a tube amp owner to this
test, was with an ARC D115. He found a barely perceptible
difference @ 3 months. By 6 months, the new tubes easily
sounded audibly better.

After 6 months was the amp re-biased before a
comparison was made with new tubes?

**Of course.

How did
you know the user only had 360 hrs. on the tubes?

**I know the customer well. He would typically listen to his system an
average of 2 hours per day.

Was this D115 an original or MKII

**Did I type MKII?



"2 years from low level tubes"... 1,440 hrs. or 60 days.
What tube models (6DJ8/6922, 12AX7, etc) numbers
are you specifically referring to, empirical experience?

**I cut my teeth on tubes. I've been servicing tube amps, since my
younger
days (age 16). In those days, I pretty much exclusively serviced musical
instrument amplification. Two amps stand out in my memory. A Wasp (New
Zealand built) amp, using 4 X KT88 tubes. The other was a Marshall head,
using 6 X 6L6 tubes. Both amps ened up on my bench, every year, almost
to
the day. Both amps ran the output tubes quite conservatively and were
highly
regarded in their day. Both amps showed a serious power drop, purely
through
emission fall of around 30% within that year. Naturally, distortion had
risen at the same time. In an audiophile setup, these performance drops
would be easily audible, by serious listeners.

Later on, I went to work for our overseas telecommunications body. Tubes
were still in use, in couple of areas. Naturally, in high power AM
transmission, the Tasman cable and, remarkably, in a thing known as
'TASI'
(Time And Speech Interpolation system). This nifty gadget occupied
several
rack bays and effectively doubled the capacity of the Tasman undersea
cable,
by placing fragments of speech into fragments of silence, during a
telephone
conversation. Back in the 1960s, it was amazing technology. It was
almost
completely a tubed device. It also required three, full time techs, to
keep
it operational. Tube changes were an HOURLY fact of life. Each tube
averaged
around 2,000 hours of life. Naturally, some lasted longer, some not so
long.

In grad school I was fortunate to have a retired military
instructor who has worked on a UNIVAC style computer
in the 40's.

**In college, I was taught by one of the designers of the KT88.

The guts of the computer covered an entire
floor, as I recall, and had several thousand tubes
(something like 16,000). It was designed for mathematical
computations in ballistics research and rarely operated for
more than half an hour at a time. The majority of all the
technician's time was spent tracking down failed tubes in
preparation for another run.

**Correct. Tube reliability is vastly over-stated proponents. Tube amp
manufacturers are well aware of reliability issues. Hence the normal
warranty on a tube amp is 90 days.


--
Trevor Wilson
www.rageaudio.com.au

"dave weil" wrote in message
...
On Fri, 28 May 2004 05:58:36 GMT, "Trevor Wilson"
wrote:


"dave weil" wrote in message
.. .
On Thu, 27 May 2004 23:03:22 GMT, "Trevor Wilson"
wrote:

4) I have had my present system turned off for two months, because
I
don't
enjoy listening to it. It's time for a change!

**It may well be. DO not discount transistors, based on one experience
and
heresay. Transistor amplifiers can offer serious and undeniable
advantages
over tube amps. PROVIDED you choose carefully. I suggest you try to
listen
to a wide range of different amps, with your speakers, before
committing
to
a product, based on what you've read about.

You can turn this around and say that you shouldn't discount tube
amps, as Trevor is wont to do, simply because *some* of them might not
be well designed.

**Absolutely. One needs only do one's homework to establish what is one
of
the better products, before purchase.


Also, she *has* heard tubes that she has enjoyed.

**I've heard tube amps I enjoy, also. However, I can get the same
enjoyment
for less cash, with a decent SS amp.

Not if you like the idea of having a tube amp.

**Now you're projecting. Read what I wrote. Here's a little mo

The ARC VT100 series, are amongst the finest amplifiers (of any technology)
that I have ever hear. Neutral, well controlled and a delight to the ear.
The Conrad Johnson Premier 16 is one of the finest preamps I've ever heard.
Neutral, well controlled and a delight to the ear. Both products can be
equalled by a GOOD SS amp and preamp, for less money. As a bonus, the SS
product may offer the following benefits:

* A MUCH longer warranty than 90 days.
* Higher reliability.
* More compact and lower mass.
* Lower noise.
* Much longer ability to retain its original specs, without adjustment/parts
replacement.

I suspect that for you,
it'd be like being in prison.

**Not at all. I find the VT100-III and the CJ Prem 16 to be utterly
beguiling products. Very superior sound quality.

For me, I like the idea of the Fisher in
the bedroom (except for the dead of summer chuckle.

**Fair enough. I don't care much for pentode amps. Triodes are more my
thing.


BTW, as you know, I have a Denon AVR2800 in the main system, but only
because it's an AV system.

**I don't have an AV system. I have no interest in aslo ran equipment.

I get far more enjoyment listening to the
Fisher, but that's not a diss of the Denon per se. I ran the Fisher as
my main amp for almost a year in the living room, so it's not a
function of the way I'm using it right now. Of course, I also had a
Mesa Baron for several months as well - talk about an amp that even a
SS maven such as yourself could love. Built like a tank...looks
industrially cool...

Now I need to get one of my Dynaco MK3 monoblock back in service (yes,
that's a failure that I can talk about - one tube started to glow
cherry red and I took it out of service - it's sitting right next to
the B&K monoblock g).

**Oh well.


--
Trevor Wilson
www.rageaudio.com.au

"dave weil" wrote in message
...
On Fri, 28 May 2004 05:54:59 GMT, "Trevor Wilson"
wrote:


"dave weil" wrote in message
.. .
On Thu, 27 May 2004 21:25:39 GMT, "Trevor Wilson"
wrote:


"Spongebob" wrote in message
...
I am considering going to a tube amp, after 25 years of solid state
amps. (Specifically, it is a conrad-johnson, but my question is
general.)
I have read comments through the years about the problems tube amps
have ("always in the shop", etc.). Is this a reality?

**It can be. Ask an ARC M300, D250 owner sometime. A badly designed
tube
amp, can be a disaster. A properly designed one can offer very high
levels
of reliability. With one big caveat: ALL tube amps gradually wear out.

You mean all TUBES gradually wear out.

**True.

There's a pretty easy solution
to that that the owner can do without sending the amp in for repair.

**Also true.

It's called "replacing the tubes". This is a little easier for the
average consumer than when a power transistor dies.

**Points:
*Transistors are VERY reliable. They do not wear out (for the most part).

That's right. They just flash out.

**Usually when something else goes wrong, or they have been poorly designed.


I have a Marantz Model Eighteen on my workbench. It is used every day of
the
working week. The output devices (on one channel) have failed exactly
once,
in 35 years. The only other failure has been (yes, you guessed it) the
CRO
tube.

And I've had several SS failures - one was an SAE 50 watt amp and one
was a B&K 4400 250 watt monoblock. I've seen the repair departments of
SS manufacturers and there is plenty of work for them.

**Sure. It is my daily bread. I did specify PROPERLY designed amplifiers.
When speaking of things like the very excellent ARC VT100, we are discussing
high end amps, which SHOULD employ high levels of build quality, with high
levels of protection. BTW: I should have mentioned that the reason why my
Marantz bit the dust, was because I connected it to a shorted speaker and
left it connected for a few minutes. The amplifiers I like have been known
to sustain a shorted output for several MONTHS, without failure.


This kind of reliability, in a well designed SS product is normal.

I don't doubt that SS amps are more reliable, especially if you
consider replacing tubes a "repair instance".

**Dollar for Dollar, they are MUCH more reliable.


*A set of output tubes in a D250 amp may run to a couple of thousand
Dollars. A set of output devices in a similarly priced SS amp (including
labour to fit) would be significantly less. At worst, maybe a Grand.

Plus service charges.

**Nope. That is all up. That would be the cost to rebuild the output stage
of a 250 Watt Krell/Levinson/Whatever. They don't fail all that often. The
last Krell I have in, required a bridge rectifier. No biggie at all.


*Have you ever wondered why no tube amp manufacturer guarantees his/her
product for more than 90 days and yet, premium SS amps have guarantees
between 5 and 20 YEARS? Do I need to spell out the commercial realities
of
the decisions?


Of course, *all* amps gradually wear out, especially internal
components like capacators.

**Absolutely. Capacitors fail when subjected to high temperatures. Wanna
speculate on which kind of amp runs hotter: SS or tube?

Capacators also fail for other reasons as well, including age.

**Heat and age are the biggies. Heat, being the biggest.


From the first minute it is switched on.

Well, transistors start dying from the first minute that an SS amp is
swiched on. Of course, the time frame is much longer, but when they
go, that's it. Time to send it to the shop.

**Back in the 1970s, RCA published a paper which outlined the life-span
of
transistors. The life-span was rated as hot/cold cycles. This because, if
a
transistor is operated (within reasonable limts) at a constant
temperature,
its lifespan will be essentially infinite (assuming it has been
manufactured
correctly). Anyway, back in the 70s, RCA determined that plastic pack
devices enjoyed a life-span in the order of 10^4 hot/cold cycles,
aluminium
cased devices, 10^5 hot/cold cycles and steel/copper cased devices, in
excess of 10^6 hot/cold cycles. 10^6 hot/cold cycles is essentially
infinite. With 30 odd years of materials technology to draw on, it is
reasonable to expect that these figures have been improved upon
significantly.

That didn't stop me from having two failures in a couple of years.
Remember, it's not just output devices that can fail either.

**Sure. I might add that my Marantz Model Eighteen uses the horrible,
unreliable Motorola aluminium case output devices. Steel/copper cased
devices last longer. Much longer.


Typically, with around 2 hours per day
of listening, you can expect around 6 months life from output tubes
and
around 2 years from low level tubes. Many tube amp lovers deny this,
but
is
is simple enough to prove. Buiy two sets of tubes. Replace the outputs
after
3 months, then 6 months. When you can hear a difference, the tubes are
worn.

I live in a town
with no tube amp dealers, and would need to send it back to the
manufacturer
if it fails. Are my knees quaking for no good reason?

**Tube amps do not travel well.

I don't know why not.

**The tubes are fragile.

Are you telling me that you can't pack tubes properly? GMAB. Yeah, if
you leave the tubes IN THE AMP, you're likely to break them.

**Seen it. Several times.


Of course, you don't have to send it back to the manufacturer just to
replace tubes.

**Quite true. However, chances are you won't need to send a transistor
amp
back at all. I gotta say, however, that I repair a lot of tube amps. In
the
majority of cases where a (output) tube goes belly-up, something else
fails
as well. This will require tech for repair.

That's true indeed. That's why you try to replace them before they go
belly up. With tubes, if you wait until failure, you've only got
yourself to blame. Most times, tubes will give you an indication that
something is wrong (not always though). Transistors just go pffffst!

**Sometimes.


By the way, I don't consider the need to bias the tubes a problem. I
would
be grateful for any feedback.

**Why do you want a tube amp?

Maybe he wants to try something new? Maybe he heard a tube amp that
sounded really good to him? Maybe he likes the look?

**Maybe she is assuming that all transistor amps sound the same.

I think that you're projecting (although that's what the SS nazis want
you to think anyway, right?)

**Some do. Clearly, not all SS amps sound the same. MOSFET amps, for
instance, suck. Big time. As do pentode amps, BTW.


It sounded to me (and yes, I'm projecting just like you) that she
wants a change and has heard some tube gear that she likes.

**And (apart from the very good advice re. room changes), I suspect she is
merely chucking the baby out with the bathwater, assuming that a tube amp
will solve all her problems.


Worse,
maybe she is assuming that all tube amps sound the same. There are bad
(and
good) examples of both kinds of amps.

Agreed. So why tell her that tube is BADDDDDDD?

**I never did. Not once. I outlined their flaws. I also made the point that
not all SS amps are created equal.



I'll have to say that I love my old 40 year old Fisher X202. It sounds
great (and plays with a lot more authority than most 40 wpc SS amps),
looks cool and is the ****. Of course, it uses output tubes that
aren't all that common anymore, so that's a drawback for that
particular amp.

**There's that too.

Fortunately, I haven't had to replace them yet. I won't like that
because they have a matched quad of RCA NOSes.

**I had the same problem with a client's Luxman. I had to (very expensively)
re-design the whole she-bang to use 6550s, since the originals were NLA.


--
Trevor Wilson
www.rageaudio.com.au

Powell wrote:

In grad school I was fortunate to have a retired military
instructor who has worked on a UNIVAC style computer
in the 40's. The guts of the computer covered an entire
floor, as I recall, and had several thousand tubes
(something like 16,000). It was designed for mathematical
computations in ballistics research and rarely operated for
more than half an hour at a time. The majority of all the
technician's time was spent tracking down failed tubes in
preparation for another run.

The IBM field office I worked for in the 60s still had at least one customer
with a 600-series tubed computer. IBM also had a vast amount of tabulating
equipment still in service, and most of the active devices in it was tubes.
For example, one card sorter I worked on was based on 10 solenoids that were
activated by 10 25l6's, their filaments hooked in two series strings of 5.
The whole box was connected to the power line without a power transformer.
There were lots of funny stories about young technicans who tried to shoot
bugs on them with oscilliscopes.

The fire control radars I worked on during the Vietnam era were still
largely tubed. You ain't lived until you try to keep a box with 400 tubes in
it going, or worked on a box with B+ lines with 5-digit voltages on them!
Been there, done that!

On Sat, 29 May 2004 03:37:08 GMT, "Trevor Wilson"
wrote:

**I've heard tube amps I enjoy, also. However, I can get the same
enjoyment
for less cash, with a decent SS amp.

Not if you like the idea of having a tube amp.

**Now you're projecting.

No, you're misunderstanding. Maybe deliberatly but probably by
accident.

Read my sentence AGAIN in relation to what you wrote.

Read what I wrote. Here's a little mo

The ARC VT100 series, are amongst the finest amplifiers (of any technology)
that I have ever hear. Neutral, well controlled and a delight to the ear.
The Conrad Johnson Premier 16 is one of the finest preamps I've ever heard.
Neutral, well controlled and a delight to the ear. Both products can be
equalled by a GOOD SS amp and preamp, for less money. As a bonus, the SS
product may offer the following benefits:

* A MUCH longer warranty than 90 days.
* Higher reliability.
* More compact and lower mass.
* Lower noise.
* Much longer ability to retain its original specs, without adjustment/parts
replacement.

I suspect that for you,
it'd be like being in prison.

**Not at all. I find the VT100-III and the CJ Prem 16 to be utterly
beguiling products. Very superior sound quality.

Superior to what?

For me, I like the idea of the Fisher in
the bedroom (except for the dead of summer chuckle.

**Fair enough. I don't care much for pentode amps. Triodes are more my
thing.


BTW, as you know, I have a Denon AVR2800 in the main system, but only
because it's an AV system.

**I don't have an AV system.

That's fine. I do.

I have no interest in aslo ran equipment.

I see. It's an also ran SS piece of ****, right? Therefore, using your
logic throughout this thread, we shouldn't bother with SS.

I get far more enjoyment listening to the
Fisher, but that's not a diss of the Denon per se. I ran the Fisher as
my main amp for almost a year in the living room, so it's not a
function of the way I'm using it right now. Of course, I also had a
Mesa Baron for several months as well - talk about an amp that even a
SS maven such as yourself could love. Built like a tank...looks
industrially cool...

Now I need to get one of my Dynaco MK3 monoblock back in service (yes,
that's a failure that I can talk about - one tube started to glow
cherry red and I took it out of service - it's sitting right next to
the B&K monoblock g).

**Oh well.

Yes, oh well indeed. Fortunately, I have no need for either pair at
the moment. I'm sure that *your* gear NEVER needs servicing because
it's perfect in every way, right?

On Sat, 29 May 2004 04:07:05 GMT, "Trevor Wilson"
wrote:


"dave weil" wrote in message
.. .
On Fri, 28 May 2004 05:54:59 GMT, "Trevor Wilson"
wrote:


"dave weil" wrote in message
.. .
On Thu, 27 May 2004 21:25:39 GMT, "Trevor Wilson"
wrote:


"Spongebob" wrote in message
...
I am considering going to a tube amp, after 25 years of solid state
amps. (Specifically, it is a conrad-johnson, but my question is
general.)
I have read comments through the years about the problems tube amps
have ("always in the shop", etc.). Is this a reality?

**It can be. Ask an ARC M300, D250 owner sometime. A badly designed
tube
amp, can be a disaster. A properly designed one can offer very high
levels
of reliability. With one big caveat: ALL tube amps gradually wear out.

You mean all TUBES gradually wear out.

**True.

There's a pretty easy solution
to that that the owner can do without sending the amp in for repair.

**Also true.

It's called "replacing the tubes". This is a little easier for the
average consumer than when a power transistor dies.

**Points:
*Transistors are VERY reliable. They do not wear out (for the most part).

That's right. They just flash out.

**Usually when something else goes wrong, or they have been poorly designed.


I have a Marantz Model Eighteen on my workbench. It is used every day of
the
working week. The output devices (on one channel) have failed exactly
once,
in 35 years. The only other failure has been (yes, you guessed it) the
CRO
tube.

And I've had several SS failures - one was an SAE 50 watt amp and one
was a B&K 4400 250 watt monoblock. I've seen the repair departments of
SS manufacturers and there is plenty of work for them.

**Sure. It is my daily bread. I did specify PROPERLY designed amplifiers.

Both of those are PROPERLY designed amplifiers.

When speaking of things like the very excellent ARC VT100, we are discussing
high end amps, which SHOULD employ high levels of build quality, with high
levels of protection. BTW: I should have mentioned that the reason why my
Marantz bit the dust, was because I connected it to a shorted speaker and
left it connected for a few minutes. The amplifiers I like have been known
to sustain a shorted output for several MONTHS, without failure.

No problems with protection with my "piece of ****" Denon.

This kind of reliability, in a well designed SS product is normal.

I don't doubt that SS amps are more reliable, especially if you
consider replacing tubes a "repair instance".

**Dollar for Dollar, they are MUCH more reliable.


*A set of output tubes in a D250 amp may run to a couple of thousand
Dollars.

I didn't address this previously, but do you think that someone who
buys a D250 (certainly not someone like you or me), cares how much a
set of output tubes costs?

You *do* know that there are plenty of WELL-DESIGNED tube amps for
less than the cost of the fairly expensive SS amps that *you* sell,
right?

A set of output devices in a similarly priced SS amp (including
labour to fit) would be significantly less. At worst, maybe a Grand.

Once again, at that price point, do you think that a double service
cost is an issue?

Plus service charges.

**Nope. That is all up. That would be the cost to rebuild the output stage
of a 250 Watt Krell/Levinson/Whatever. They don't fail all that often. The
last Krell I have in, required a bridge rectifier. No biggie at all.

Well, that's not what you wrote. You wrote about the cost of output
devices.

*Have you ever wondered why no tube amp manufacturer guarantees his/her
product for more than 90 days and yet, premium SS amps have guarantees
between 5 and 20 YEARS? Do I need to spell out the commercial realities
of
the decisions?


Of course, *all* amps gradually wear out, especially internal
components like capacators.

**Absolutely. Capacitors fail when subjected to high temperatures. Wanna
speculate on which kind of amp runs hotter: SS or tube?

Capacators also fail for other reasons as well, including age.

**Heat and age are the biggies. Heat, being the biggest.

Thank you for acknowledging that.

From the first minute it is switched on.

Well, transistors start dying from the first minute that an SS amp is
swiched on. Of course, the time frame is much longer, but when they
go, that's it. Time to send it to the shop.

**Back in the 1970s, RCA published a paper which outlined the life-span
of
transistors. The life-span was rated as hot/cold cycles. This because, if
a
transistor is operated (within reasonable limts) at a constant
temperature,
its lifespan will be essentially infinite (assuming it has been
manufactured
correctly). Anyway, back in the 70s, RCA determined that plastic pack
devices enjoyed a life-span in the order of 10^4 hot/cold cycles,
aluminium
cased devices, 10^5 hot/cold cycles and steel/copper cased devices, in
excess of 10^6 hot/cold cycles. 10^6 hot/cold cycles is essentially
infinite. With 30 odd years of materials technology to draw on, it is
reasonable to expect that these figures have been improved upon
significantly.

That didn't stop me from having two failures in a couple of years.
Remember, it's not just output devices that can fail either.

**Sure. I might add that my Marantz Model Eighteen uses the horrible,
unreliable Motorola aluminium case output devices. Steel/copper cased
devices last longer. Much longer.


Typically, with around 2 hours per day
of listening, you can expect around 6 months life from output tubes
and
around 2 years from low level tubes. Many tube amp lovers deny this,
but
is
is simple enough to prove. Buiy two sets of tubes. Replace the outputs
after
3 months, then 6 months. When you can hear a difference, the tubes are
worn.

I live in a town
with no tube amp dealers, and would need to send it back to the
manufacturer
if it fails. Are my knees quaking for no good reason?

**Tube amps do not travel well.

I don't know why not.

**The tubes are fragile.

Are you telling me that you can't pack tubes properly? GMAB. Yeah, if
you leave the tubes IN THE AMP, you're likely to break them.

**Seen it. Several times.

Well, if I pack a solid state amp in a thin carboard box, it can be
damaged as well. I've seen *it* happen to something that was shipped
to me once.

Don't condemn a product because of user abuse.

Of course, you don't have to send it back to the manufacturer just to
replace tubes.

**Quite true. However, chances are you won't need to send a transistor
amp
back at all. I gotta say, however, that I repair a lot of tube amps.

No, chances are, if you own a transistor amp long enough, you *will*
have to take it to the shop. You make it sound like you never repair
transistor amps. I'll bet this isn't at all true, because I doubt you
make a good living (on the service side) working exclusively on tube
amps.

In
the
majority of cases where a (output) tube goes belly-up, something else
fails
as well. This will require tech for repair.

That's true indeed. That's why you try to replace them before they go
belly up. With tubes, if you wait until failure, you've only got
yourself to blame. Most times, tubes will give you an indication that
something is wrong (not always though). Transistors just go pffffst!

**Sometimes.

NO, almost always. If they fail, they fail. They don't decline over
time like a tube does, audibly at least.

By the way, I don't consider the need to bias the tubes a problem. I
would
be grateful for any feedback.

**Why do you want a tube amp?

Maybe he wants to try something new? Maybe he heard a tube amp that
sounded really good to him? Maybe he likes the look?

**Maybe she is assuming that all transistor amps sound the same.

I think that you're projecting (although that's what the SS nazis want
you to think anyway, right?)

**Some do. Clearly, not all SS amps sound the same. MOSFET amps, for
instance, suck. Big time.

Well, we disagree. And you can't make this claim as anything other
than your own personal preference.

As do pentode amps, BTW.

Again, just your personal preference. That's why you need an amp like
the Mesa Baron. You can run it in pentode, triode or a combination
thereof.

It sounded to me (and yes, I'm projecting just like you) that she
wants a change and has heard some tube gear that she likes.

**And (apart from the very good advice re. room changes), I suspect she is
merely chucking the baby out with the bathwater, assuming that a tube amp
will solve all her problems.

I don't think that she's thinking that. She's acting like a consumer
that's looking for a change and she wants to try tube amps. Why don't
you guys understand this sort of consumer behavior. You get so
entrenched in your hoary thinking that you can't understand others'
possible motivations.

Worse,
maybe she is assuming that all tube amps sound the same. There are bad
(and
good) examples of both kinds of amps.

Agreed. So why tell her that tube is BADDDDDDD?

**I never did. Not once. I outlined their flaws. I also made the point that
not all SS amps are created equal.

You haven't pointed out *any* reason for her to consider tubes.
Everytime you praise tubes, the subtext (and the overt as well) is
that you can do better with SS.

I'll have to say that I love my old 40 year old Fisher X202. It sounds
great (and plays with a lot more authority than most 40 wpc SS amps),
looks cool and is the ****. Of course, it uses output tubes that
aren't all that common anymore, so that's a drawback for that
particular amp.

**There's that too.

Fortunately, I haven't had to replace them yet. I won't like that
because they have a matched quad of RCA NOSes.

**I had the same problem with a client's Luxman. I had to (very expensively)
re-design the whole she-bang to use 6550s, since the originals were NLA.

Then you should be glad when people are willing to go the tube route.
Otherwise, you can chuck your repair business out the window. Or are
you saying that you are basically dealing with idiots who are just too
stupid to realize that tubes are ruining their lives? Why don't you
take a stand andstop enabling them?

From: dave weil
Date: 5/29/2004 7:57 AM Pacific Standard Time
Message-id:



I didn't address this previously, but do you think that someone who
buys a D250 (certainly not someone like you or me), cares how much a
set of output tubes costs?

Some of them. While some may be swimming in money some may have saved up and
spent the whole budget for several years on a piece of equipment.

"Trevor Wilson" said:

**I cut my teeth on tubes. I've been servicing tube amps, since my younger
days (age 16). In those days, I pretty much exclusively serviced musical
instrument amplification. Two amps stand out in my memory. A Wasp (New
Zealand built) amp, using 4 X KT88 tubes. The other was a Marshall head,
using 6 X 6L6 tubes. Both amps ened up on my bench, every year, almost to
the day. Both amps ran the output tubes quite conservatively and were highly
regarded in their day. Both amps showed a serious power drop, purely through
emission fall of around 30% within that year. Naturally, distortion had
risen at the same time. In an audiophile setup, these performance drops
would be easily audible, by serious listeners.

Show me ANY Marshall that runs the tubes conservatively.
In fact, show me ANY musician that does. :-)

In most home amplifiers, NFB ensures that tube wear isn't degrading
the sound up until Aol gets too low.
With power tubes, this point in time varies from 2...5 years and many
last even longer.

--
Sander deWaal
Vacuum Audio Consultancy

(Marc Phillips) said:

By the way, I just bought a lot of 20 7189s on e-bay. I guess that means I've
been sucked in.

When they're NOS, you shouldn't have any problem in reselling them
with profit.

--
Sander deWaal
Vacuum Audio Consultancy

"Arny Krueger" said:

The IBM field office I worked for in the 60s still had at least one customer
with a 600-series tubed computer. IBM also had a vast amount of tabulating
equipment still in service, and most of the active devices in it was tubes.
For example, one card sorter I worked on was based on 10 solenoids that were
activated by 10 25l6's, their filaments hooked in two series strings of 5.
The whole box was connected to the power line without a power transformer.

You meant to type 25L6, I assume?

There were lots of funny stories about young technicans who tried to shoot
bugs on them with oscilliscopes.

Any novice knows you have to isolate the safety ground from the
scope's mains lead, or (preferably) use an isolating transformer.
Guess the US Army training left some to be desired, hm?

The fire control radars I worked on during the Vietnam era were still
largely tubed. You ain't lived until you try to keep a box with 400 tubes in
it going, or worked on a box with B+ lines with 5-digit voltages on them!
Been there, done that!

10.000 volts only for the klystron itself.
Associating equipment surely ran on "3-digit voltages" as you so aptly
put it.

Thanks for admitting that you lived, BTW.
What's your current status?


;-)


--
Sander deWaal
Vacuum Audio Consultancy

Sander said:

(Marc Phillips) said:

By the way, I just bought a lot of 20 7189s on e-bay. I guess that means
I've
been sucked in.

When they're NOS, you shouldn't have any problem in reselling them
with profit.

From what I've been told, they're the last batch of Russian 7189s made before
the factory stopped production.

Since they cost me less than $4 each, I'm not going to sweat it if I don't keep
the Scott LK-48 around for more than a few years.

Boon

Paul Dormer said:

The fire control radars I worked on during the Vietnam era were still
largely tubed. You ain't lived until you try to keep a box with 400 tubes in
it going, or worked on a box with B+ lines with 5-digit voltages on them!
Been there, done that!

Was this before or after you invented the wheel?

Thank's Dormier for admitting you know squat about me or my
accomplihsements anywhere in sky, land or, sea, Doemror.

LOt";:'S !

Its like, I've baldly gone where no man has gone before lost his hair
in a train wreck of a thread, hardly.


Did any woodworking, lately?

;-)

--
Sander deWaal
Vacuum Audio Consultancy

(Marc Phillips) said:

From what I've been told, they're the last batch of Russian 7189s made before
the factory stopped production.

Don't worry, they'll get scarce soon enough.

Since they cost me less than $4 each, I'm not going to sweat it if I don't keep
the Scott LK-48 around for more than a few years.

You could make some people over in RATubes very happy..........

--
Sander deWaal
Vacuum Audio Consultancy

Sander said:

(Marc Phillips) said:

From what I've been told, they're the last batch of Russian 7189s made
before
the factory stopped production.

Don't worry, they'll get scarce soon enough.

Since they cost me less than $4 each, I'm not going to sweat it if I don't
keep
the Scott LK-48 around for more than a few years.

You could make some people over in RATubes very happy..........

It's actually a Russian guy selling them off in lots of 4, 10 and 20. I was
told by the guy restoring my Scott to get some from him as soon as possible so
that I'd never have to worry about finding them later. Since the Scott will be
my first tube amp, something tells me that it won't be my last by any means.

The audio crowd I've been hanging out with seems to be about getting a Scott
299, then a Fisher 400, then a Dynaco ST-70, then a Mac MC40, then finally the
Marantz 7s and 8s. Who knows where this will lead me.

Boon

Mr. Middius said:

Mark Philip's wroted:

When they're NOS, you shouldn't have
any problem in reselling them
with profit.

From what I've been told, they're the last batch of Rus
sian 7189s made before
the factory stopped productio
n.

Since they cost me less than $4 each, I'm not going to sweat it if I don't
keep the Scott LK-48 around for more than a few
years.

Boon


Its like you could prove that "4$" dollers claim Philips. Been there
done that when, you were still figuring out that vinyl is for
antidelusionist bigot's. Allow me to demonstrate Phillups your being an
idiot again. LOL! I had a tube amp once but I grew up. How about you
Philiips? When are you going to grow up? Love that Arnarchy thing.
ROOFMLAMWO!

Thanks for admitting Middius that Detective Fowler is an antidiluvian bigot who
posts to audio groups without knowing about you and your thugs such as Philips,
Richman, Weil, Dormer, Wheeler, and the Devil. Thanks but no thanks.

Boon

Tube Amp Reliability???
From: (Marc Phillips)
Date: 5/29/2004 12:23 PM Pacific Standard Time
Message-id:

Sander said:

(Marc Phillips) said:

From what I've been told, they're the last batch of Russian 7189s made
before
the factory stopped production.

Don't worry, they'll get scarce soon enough.

Since they cost me less than $4 each, I'm not going to sweat it if I don't
keep
the Scott LK-48 around for more than a few years.

You could make some people over in RATubes very happy..........

It's actually a Russian guy selling them off in lots of 4, 10 and 20. I was
told by the guy restoring my Scott to get some from him as soon as possible
so
that I'd never have to worry about finding them later. Since the Scott will
be
my first tube amp, something tells me that it won't be my last by any means.

The audio crowd I've been hanging out with seems to be about getting a Scott
299, then a Fisher 400, then a Dynaco ST-70, then a Mac MC40, then finally
the
Marantz 7s and 8s. Who knows where this will lead me.

Boon







If you know where you are going just take the straight line there. Get the
Marantz.

"dave weil" wrote in message
...
On Sat, 29 May 2004 03:37:08 GMT, "Trevor Wilson"
wrote:

**I've heard tube amps I enjoy, also. However, I can get the same
enjoyment
for less cash, with a decent SS amp.

Not if you like the idea of having a tube amp.

**Now you're projecting.

No, you're misunderstanding. Maybe deliberatly but probably by
accident.

Read my sentence AGAIN in relation to what you wrote.

**OK. I see where I misunderstood.


Read what I wrote. Here's a little mo

The ARC VT100 series, are amongst the finest amplifiers (of any
technology)
that I have ever hear. Neutral, well controlled and a delight to the ear.
The Conrad Johnson Premier 16 is one of the finest preamps I've ever
heard.
Neutral, well controlled and a delight to the ear. Both products can be
equalled by a GOOD SS amp and preamp, for less money. As a bonus, the SS
product may offer the following benefits:

* A MUCH longer warranty than 90 days.
* Higher reliability.
* More compact and lower mass.
* Lower noise.
* Much longer ability to retain its original specs, without
adjustment/parts
replacement.

I suspect that for you,
it'd be like being in prison.

**Not at all. I find the VT100-III and the CJ Prem 16 to be utterly
beguiling products. Very superior sound quality.

Superior to what?

**Almost any other product, from any manufacturer, except similarly priced
(more correctly, somewhat less expensive) properly designed SS products.


For me, I like the idea of the Fisher in
the bedroom (except for the dead of summer chuckle.

**Fair enough. I don't care much for pentode amps. Triodes are more my
thing.


BTW, as you know, I have a Denon AVR2800 in the main system, but only
because it's an AV system.

**I don't have an AV system.

That's fine. I do.

I have no interest in aslo ran equipment.

I see. It's an also ran SS piece of ****, right?

**Not sepcifically. The system sucks. MOST of the SS products which happen
to be used with such flawed systems suck. It would be simply impossible to
build a tubed system to duplicate the functions of a surround sound system
anyway. It would require a building the size of a small office block to
house the equipment.

Therefore, using your
logic throughout this thread, we shouldn't bother with SS.

**Nope. If you recall earlier, I said: There are some good tube products and
some bad tube products. There are some good SS products and some bad SS
products.


I get far more enjoyment listening to the
Fisher, but that's not a diss of the Denon per se. I ran the Fisher as
my main amp for almost a year in the living room, so it's not a
function of the way I'm using it right now. Of course, I also had a
Mesa Baron for several months as well - talk about an amp that even a
SS maven such as yourself could love. Built like a tank...looks
industrially cool...

Now I need to get one of my Dynaco MK3 monoblock back in service (yes,
that's a failure that I can talk about - one tube started to glow
cherry red and I took it out of service - it's sitting right next to
the B&K monoblock g).

**Oh well.

Yes, oh well indeed. Fortunately, I have no need for either pair at
the moment. I'm sure that *your* gear NEVER needs servicing because
it's perfect in every way, right?

**Of course not. The equipment I have in my main system is 8 years old and
has never been touched by a screwdriver, nor soldering iron. I have a 28
year old one in my second system, which has been serviced once. I expect to
get at least another 20+ years out of both systems, before I need to do
anything at all. Maybe longer. Well, except for my sources. Lasers fail
regularly. Stylii wear out. Transistors don't. All the switches are heavily
gold plated. Experience tells me that they have a life span in excess of 25
years. The pots conductive plastic and 15 years have exhibited a zero
failure rate (with more than 7,000 units manufactured). The amplifier in the
main system is forced air cooled, with cool air drawn past the caps, before
reaching the output devices. The caps also last longer than in a
conventional design, because electros are kept more or less at room
temperature at all times.

As a tech, I do tend to gravitate towards more elegant (design-wise),
reliable designs, rather than what happens to be trendy, or pretty. Pretty,
to me, is an elegant solution to a problem, not necessarily a thick face
plate, or glowing tubes.


--
Trevor Wilson
www.rageaudio.com.au

S888Wheel said:

Tube Amp Reliability???
From: (Marc Phillips)
Date: 5/29/2004 12:23 PM Pacific Standard Time
Message-id:

Sander said:

(Marc Phillips) said:

From what I've been told, they're the last batch of Russian 7189s made
before
the factory stopped production.

Don't worry, they'll get scarce soon enough.

Since they cost me less than $4 each, I'm not going to sweat it if I don't
keep
the Scott LK-48 around for more than a few years.

You could make some people over in RATubes very happy..........

It's actually a Russian guy selling them off in lots of 4, 10 and 20. I was
told by the guy restoring my Scott to get some from him as soon as possible
so
that I'd never have to worry about finding them later. Since the Scott will
be
my first tube amp, something tells me that it won't be my last by any means.

The audio crowd I've been hanging out with seems to be about getting a Scott
299, then a Fisher 400, then a Dynaco ST-70, then a Mac MC40, then finally
the
Marantz 7s and 8s. Who knows where this will lead me.

Boon







If you know where you are going just take the straight line there. Get the
Marantz.







Tube Amp Reliability???
From: (Marc Phillips)
Date: 5/29/2004 12:23 PM Pacific Standard Time
Message-id:

Sander said:

(Marc Phillips) said:

From what I've been told, they're the last batch of Russian 7189s made
before
the factory stopped production.

Don't worry, they'll get scarce soon enough.

Since they cost me less than $4 each, I'm not going to sweat it if I don't
keep
the Scott LK-48 around for more than a few years.

You could make some people over in RATubes very happy..........

It's actually a Russian guy selling them off in lots of 4, 10 and 20. I was
told by the guy restoring my Scott to get some from him as soon as possible
so
that I'd never have to worry about finding them later. Since the Scott will
be
my first tube amp, something tells me that it won't be my last by any means.

The audio crowd I've been hanging out with seems to be about getting a Scott
299, then a Fisher 400, then a Dynaco ST-70, then a Mac MC40, then finally
the
Marantz 7s and 8s. Who knows where this will lead me.

Boon







If you know where you are going just take the straight line there. Get the
Marantz.

I never really thought about it until S.H. put the idea in my head last night.

Boon

"dave weil" wrote in message
...
On Sat, 29 May 2004 04:07:05 GMT, "Trevor Wilson"
wrote:


"dave weil" wrote in message
.. .
On Fri, 28 May 2004 05:54:59 GMT, "Trevor Wilson"
wrote:


"dave weil" wrote in message
.. .
On Thu, 27 May 2004 21:25:39 GMT, "Trevor Wilson"
wrote:


"Spongebob" wrote in message
...
I am considering going to a tube amp, after 25 years of solid
state
amps. (Specifically, it is a conrad-johnson, but my question is
general.)
I have read comments through the years about the problems tube
amps
have ("always in the shop", etc.). Is this a reality?

**It can be. Ask an ARC M300, D250 owner sometime. A badly designed
tube
amp, can be a disaster. A properly designed one can offer very high
levels
of reliability. With one big caveat: ALL tube amps gradually wear
out.

You mean all TUBES gradually wear out.

**True.

There's a pretty easy solution
to that that the owner can do without sending the amp in for repair.

**Also true.

It's called "replacing the tubes". This is a little easier for the
average consumer than when a power transistor dies.

**Points:
*Transistors are VERY reliable. They do not wear out (for the most
part).

That's right. They just flash out.

**Usually when something else goes wrong, or they have been poorly
designed.


I have a Marantz Model Eighteen on my workbench. It is used every day
of
the
working week. The output devices (on one channel) have failed exactly
once,
in 35 years. The only other failure has been (yes, you guessed it) the
CRO
tube.

And I've had several SS failures - one was an SAE 50 watt amp and one
was a B&K 4400 250 watt monoblock. I've seen the repair departments of
SS manufacturers and there is plenty of work for them.

**Sure. It is my daily bread. I did specify PROPERLY designed amplifiers.

Both of those are PROPERLY designed amplifiers.

**Really? Zero Global NFB? Completely stable, regardless of load? Very
reliable?


When speaking of things like the very excellent ARC VT100, we are
discussing
high end amps, which SHOULD employ high levels of build quality, with
high
levels of protection. BTW: I should have mentioned that the reason why my
Marantz bit the dust, was because I connected it to a shorted speaker and
left it connected for a few minutes. The amplifiers I like have been
known
to sustain a shorted output for several MONTHS, without failure.

No problems with protection with my "piece of ****" Denon.

**Of course not. The Denon will work for 5 years, then it develope problems
with switches and pots. Later, it will fail and be uneconomical to service.
The protection systems in most mass market products are quite good.
Everything else is crap.


This kind of reliability, in a well designed SS product is normal.

I don't doubt that SS amps are more reliable, especially if you
consider replacing tubes a "repair instance".

**Dollar for Dollar, they are MUCH more reliable.


*A set of output tubes in a D250 amp may run to a couple of thousand
Dollars.

I didn't address this previously, but do you think that someone who
buys a D250 (certainly not someone like you or me), cares how much a
set of output tubes costs?

**Not the issue.


You *do* know that there are plenty of WELL-DESIGNED tube amps for
less than the cost of the fairly expensive SS amps that *you* sell,
right?

**Nope.


A set of output devices in a similarly priced SS amp (including
labour to fit) would be significantly less. At worst, maybe a Grand.

Once again, at that price point, do you think that a double service
cost is an issue?

**Yes. I deal with people who own this kind of stuff, every day. They watch
their pennies. I guess that's why they can afford to buy them in the first
place.


Plus service charges.

**Nope. That is all up. That would be the cost to rebuild the output
stage
of a 250 Watt Krell/Levinson/Whatever. They don't fail all that often.
The
last Krell I have in, required a bridge rectifier. No biggie at all.

Well, that's not what you wrote. You wrote about the cost of output
devices.

**Here's what I wrote:

"A set of output devices in a similarly priced SS amp (including
labour to fit) would be significantly less. At worst, maybe a Grand."

Please re-read it. Note these words: (including labour to fit)



*Have you ever wondered why no tube amp manufacturer guarantees
his/her
product for more than 90 days and yet, premium SS amps have guarantees
between 5 and 20 YEARS? Do I need to spell out the commercial
realities
of
the decisions?


Of course, *all* amps gradually wear out, especially internal
components like capacators.

**Absolutely. Capacitors fail when subjected to high temperatures.
Wanna
speculate on which kind of amp runs hotter: SS or tube?

Capacators also fail for other reasons as well, including age.

**Heat and age are the biggies. Heat, being the biggest.

Thank you for acknowledging that.

**Google my name and electrolytic caps. You will find many references from
me on this issue. It is a serious problem with all amplifiers.


From the first minute it is switched on.

Well, transistors start dying from the first minute that an SS amp
is
swiched on. Of course, the time frame is much longer, but when they
go, that's it. Time to send it to the shop.

**Back in the 1970s, RCA published a paper which outlined the
life-span
of
transistors. The life-span was rated as hot/cold cycles. This because,
if
a
transistor is operated (within reasonable limts) at a constant
temperature,
its lifespan will be essentially infinite (assuming it has been
manufactured
correctly). Anyway, back in the 70s, RCA determined that plastic pack
devices enjoyed a life-span in the order of 10^4 hot/cold cycles,
aluminium
cased devices, 10^5 hot/cold cycles and steel/copper cased devices, in
excess of 10^6 hot/cold cycles. 10^6 hot/cold cycles is essentially
infinite. With 30 odd years of materials technology to draw on, it is
reasonable to expect that these figures have been improved upon
significantly.

That didn't stop me from having two failures in a couple of years.
Remember, it's not just output devices that can fail either.

**Sure. I might add that my Marantz Model Eighteen uses the horrible,
unreliable Motorola aluminium case output devices. Steel/copper cased
devices last longer. Much longer.


Typically, with around 2 hours per day
of listening, you can expect around 6 months life from output tubes
and
around 2 years from low level tubes. Many tube amp lovers deny
this,
but
is
is simple enough to prove. Buiy two sets of tubes. Replace the
outputs
after
3 months, then 6 months. When you can hear a difference, the tubes
are
worn.

I live in a town
with no tube amp dealers, and would need to send it back to the
manufacturer
if it fails. Are my knees quaking for no good reason?

**Tube amps do not travel well.

I don't know why not.

**The tubes are fragile.

Are you telling me that you can't pack tubes properly? GMAB. Yeah, if
you leave the tubes IN THE AMP, you're likely to break them.

**Seen it. Several times.

Well, if I pack a solid state amp in a thin carboard box, it can be
damaged as well. I've seen *it* happen to something that was shipped
to me once.

Don't condemn a product because of user abuse.

Of course, you don't have to send it back to the manufacturer just
to
replace tubes.

**Quite true. However, chances are you won't need to send a transistor
amp
back at all. I gotta say, however, that I repair a lot of tube amps.

No, chances are, if you own a transistor amp long enough, you *will*
have to take it to the shop.

**I never suggested otherwise. In fact, removing the tubes from the
equation, you would find that tube amps are slightly less reliable than SS
amps (those output transformers bump up the unreliability figures somewhat).
However, when the tubes are added into the mix, reliability goes out the
window. That is reflected in the manufacturer's guarantees. None offer a
guarantee beyond 90 days. That should tell you something.

You make it sound like you never repair
transistor amps.

**I repair LOTS of them. However, there are MANY more tube amps on the
market than SS ones. Many, many more.

I'll bet this isn't at all true, because I doubt you
make a good living (on the service side) working exclusively on tube
amps.

**Of course. There are bugger all in the market place.


In
the
majority of cases where a (output) tube goes belly-up, something else
fails
as well. This will require tech for repair.

That's true indeed. That's why you try to replace them before they go
belly up. With tubes, if you wait until failure, you've only got
yourself to blame. Most times, tubes will give you an indication that
something is wrong (not always though). Transistors just go pffffst!

**Sometimes.

NO, almost always. If they fail, they fail. They don't decline over
time like a tube does, audibly at least.

**Transistors (nowadays) fail in several ways:

* Very soon after purchase. This is likely due to a manufacturing defect.
This kind of failure mode is now very rare.
* If the product has been abused and the manufacturer has not incorporated
adequate protection mechanisms in the product.
* Failure of another component, which causes the transistor to eventually
fail.


By the way, I don't consider the need to bias the tubes a
problem. I
would
be grateful for any feedback.

**Why do you want a tube amp?

Maybe he wants to try something new? Maybe he heard a tube amp that
sounded really good to him? Maybe he likes the look?

**Maybe she is assuming that all transistor amps sound the same.

I think that you're projecting (although that's what the SS nazis want
you to think anyway, right?)

**Some do. Clearly, not all SS amps sound the same. MOSFET amps, for
instance, suck. Big time.

Well, we disagree. And you can't make this claim as anything other
than your own personal preference.

**Wrong. MOSFETs have several, serious limitations, which can be completely
eliminated by the use of BJTs. These a
* MOSFETs are FAR less linear than BJTs, at low currents. MOSFETs must be
run at very high bias currents, in order to overcome this debilitating
disadvantage. Either that, or huge amounts of Global NFB must be employed
(which leads to other problems).
* MOSFETs are slightly less linear than modern BJTs, at higher currents.
* MOSFETs exhibit a characteristic known as 'Negative Temperature
Co-efficient of gm'. Basically, this means that thye tend to 'choke off'
transients in music. Don't believe me? Listen to a regular, low bias MOSFET
amp, compared to (say) a Phase Linear 400 sometime. You'll undestand
immmediately.

MOSFETs, contrary to popular folklore, are not like tubes. Their transfer
characteristic is similar to Pentodes (albeit with much higher distortion),
but utterly dissimilar to Triodes. In a sense, triodes are much like BJTs,
in their output characteristics. Input characteristics of MOSFETs ARE
similar to tubes (ie: High input impedance).


As do pentode amps, BTW.

Again, just your personal preference. That's why you need an amp like
the Mesa Baron. You can run it in pentode, triode or a combination
thereof.

**Not whilst there are output transformers in there to bugger things up.


It sounded to me (and yes, I'm projecting just like you) that she
wants a change and has heard some tube gear that she likes.

**And (apart from the very good advice re. room changes), I suspect she
is
merely chucking the baby out with the bathwater, assuming that a tube amp
will solve all her problems.

I don't think that she's thinking that. She's acting like a consumer
that's looking for a change and she wants to try tube amps. Why don't
you guys understand this sort of consumer behavior.

**I understand it very well. I have fought against this kind of
misinformation for several decades.

You get so
entrenched in your hoary thinking that you can't understand others'
possible motivations.

**I understand it better than you realise.


Worse,
maybe she is assuming that all tube amps sound the same. There are bad
(and
good) examples of both kinds of amps.

Agreed. So why tell her that tube is BADDDDDDD?

**I never did. Not once. I outlined their flaws. I also made the point
that
not all SS amps are created equal.

You haven't pointed out *any* reason for her to consider tubes.
Everytime you praise tubes, the subtext (and the overt as well) is
that you can do better with SS.

**Only because that is an immutable fact.


I'll have to say that I love my old 40 year old Fisher X202. It
sounds
great (and plays with a lot more authority than most 40 wpc SS
amps),
looks cool and is the ****. Of course, it uses output tubes that
aren't all that common anymore, so that's a drawback for that
particular amp.

**There's that too.

Fortunately, I haven't had to replace them yet. I won't like that
because they have a matched quad of RCA NOSes.

**I had the same problem with a client's Luxman. I had to (very
expensively)
re-design the whole she-bang to use 6550s, since the originals were NLA.

Then you should be glad when people are willing to go the tube route.

**I like servicing tube amps. I don't usually require a schematic and the
faults tend to be easier to find. That is not the issue.

Otherwise, you can chuck your repair business out the window. Or are
you saying that you are basically dealing with idiots who are just too
stupid to realize that tubes are ruining their lives? Why don't you
take a stand andstop enabling them?

**I tell them. They usually don't listen.


--
Trevor Wilson
www.rageaudio.com.au

I own Spendors (SP100s), and I've been running them with a LFD Mistral for the
last three years. Although I've experienced none of the annoying
characteristics you've complained about, I did need something more. I've
recently found the answer with a 1963 Scott LK-48 integrated tube amp with the
rare chocolate brown faceplate, all lovingly and painstakingly restored, piece
by piece, to mint condition. And it cost me less than one-fifth of what I paid
for my cartridge alone.

I parted out piles of Dynacos and Scotts to keep Fender and Marshall
amps going in the old days. For the most part they sucked. The Dyna
pre was semi-OK when reworked, by the time most of the modders got
done all that was left was the chassis. The ST70 had a power xfmr
about half as big as needed, so if you ran only one channel it worked
okay. Again, by the time people got done fixing the problems all that
was left was the chassis!

(Marc Phillips) said:

From what I've been told, they're the last batch of Russian 7189s
made before
the factory stopped production.

Don't worry, they'll get scarce soon enough.

Since they cost me less than $4 each, I'm not going to sweat it if I
don't keep
the Scott LK-48 around for more than a few years.

You could make some people over in RATubes very happy..........

It's actually a Russian guy selling them off in lots of 4, 10 and 20.
I was
told by the guy restoring my Scott to get some from him as soon as
possible so
that I'd never have to worry about finding them later. Since the
Scott will be
my first tube amp, something tells me that it won't be my last by any
means.

The audio crowd I've been hanging out with seems to be about getting
a Scott
299, then a Fisher 400, then a Dynaco ST-70, then a Mac MC40, then
finally the
Marantz 7s and 8s. Who knows where this will lead me.

Why **** with all this schlock and take it up the kazoo on resale?
Buy the best, cry once. I think the VAC-built Marantzes are still
available NIB, or certainly used. Eighties-era VTLs are very similar
to Marantzes in sound and design. Or here's an idea, get a pair of
output transformers from Sowter in England (or that f****t in Philly
that worshipth Earthel B. Harrithon) and build one yourself thereby
learning something?



Don't be afraid of a tube amp...it may change your life!

It's a sad life changed by a tube amplifier, or any other. I'd hold
out for a Phantom jet or at least a weekend in Manhattan on top of
several supermodels.(Sequentially, of course...)

Sander deWaal wrote:
"Arny Krueger" said:

The IBM field office I worked for in the 60s still had at least one
customer with a 600-series tubed computer. IBM also had a vast
amount of tabulating equipment still in service, and most of the
active devices in it was tubes. For example, one card sorter I
worked on was based on 10 solenoids that were activated by 10
25l6's, their filaments hooked in two series strings of 5. The whole
box was connected to the power line without a power transformer.

You meant to type 25L6, I assume?

Can't read lower case letters any more, Sander? Suffering from the
well-known effects of a social disease?

There were lots of funny stories about young technicans who tried to
shoot bugs on them with oscilliscopes.

Any novice knows you have to isolate the safety ground from the
scope's mains lead, or (preferably) use an isolating transformer.

In fact, using a scope on tubed tabulating equipment was usually known as
barking up the wrong tree,

Guess the US Army training left some to be desired, hm?

Nope. A lot of the Army equipment had isolation transformers, built-in.

The fire control radars I worked on during the Vietnam era were still
largely tubed. You ain't lived until you try to keep a box with 400
tubes in it going, or worked on a box with B+ lines with 5-digit
voltages on them! Been there, done that!

10.000 volts only for the klystron itself.

Off by about half.

Associating equipment surely ran on "3-digit voltages" as you so aptly
put it.

...or one-digit for the filaments. DC, though.

snip childish comment, leaving mostly ignorant comments