[Andre Jute]

On Oct 19, 12:11 am, "Iain Churches" wrote:
"Andre Jute" wrote

Real tubies build real valve amp kits, like
my Velleman K4000, three EL34 per side for 18W in Class A and 101W in
Class B (measured, they claim only 16/96W). Now that is an amp that
leaves hairy footprints.

Interesting you should mention the Velleman. It is indeed a good sounding
amp. It is a long time since I have seen a K4000, but I seem to recollect
it had four EL34's in push pull parallel per side.

PPP.

It seems as though the K4000 is discontinued.

Mine is ancient. Early to mid-1990s, at a guess, without looking up
the reviews I wrote of it.

I listened to a 4040 not too long ago, with a pair of splendid Tannoy
Canterbury
SE speakers. Very pleasing indeed. The amp was running far below its full
power potential.

Quite a bizarre thing to say, I suppose, but the Velleman is probably
overmatched to the Tannoys. It has around 16 to 18W in Class A alone.
I sometimes used mine for driving a bass bin, where its 100W in Class
A/B could sometimes come into play, at least theoretically (I'm not a
headbanger).

The noise floor was exceptionally low. Later, a quick
look on the bench revealed the noise floor to be 100µV, so a
SNR of 105dB and at 96W, the THD was only 0.1%

It depends on your outlook whether you view the Velleman K40x0 as that
rare thing, a perfect all-round amp -- or as a perfectly schizophrenic
amp: on the one hand superbly well designed and good-sounding,
escpecially in that very hefty Class A segment, a delicate match to
ESL-63, on the other hand a brutish bass thumper on demand. As an all-
round amp of excellent quality and durability it is of course a very
great bargain at the price.

The Belgians know how to make more than just chocolates:-)

We used to make a round trip of 50 miles to buy Belgian chocolates in
Cork...

Regards
Iain

Andre Jute
Visit Jute on Amps at http://members.lycos.co.uk/fiultra/
"wonderfully well written and reasoned information
for the tube audio constructor"
John Broskie TubeCAD & GlassWare
"an unbelievably comprehensive web site
containing vital gems of wisdom"
Stuart Perry Hi-Fi News & Record Review

[Multi-grid]

overmatched to the Tannoys. It has around 16 to 18W in Class A alone.
I sometimes used mine for driving a bass bin, where its 100W in Class
A/B could sometimes come into play, at least theoretically (I'm not a
headbanger).



hey-Hey!!!,
An amp with maximum output happening with one phase of its PP set cut
off is *NOT* class A. A real class A amp has both phases conducting at
maximum power, and not from some variable pitch grid winding, remote
cut-off stuff either.

That Vellman amp is an AB, and barely so at that.
cheers,
Douglas

[John Byrns]

In article . com,
Multi-grid wrote:

hey-Hey!!!,
An amp with maximum output happening with one phase of its PP set cut
off is *NOT* class A. A real class A amp has both phases conducting at
maximum power, and not from some variable pitch grid winding, remote
cut-off stuff either.

Is there actually a power tube with a variable pitch grid winding
designed to do this? I never heard about it before, inquiring minds
want to know more.


Regards,

John Byrns

--
Surf my web pages at, http://fmamradios.com/

[Multi-grid]

On Oct 20, 2:18 am, John Byrns wrote:
In article . com,

Multi-grid wrote:
hey-Hey!!!,
An amp with maximum output happening with one phase of its PP set cut
off is *NOT* class A. A real class A amp has both phases conducting at
maximum power, and not from some variable pitch grid winding, remote
cut-off stuff either.

Is there actually a power tube with a variable pitch grid winding
designed to do this? I never heard about it before, inquiring minds
want to know more.

Regards,

John Byrns

--
Surf my web pages at, http://fmamradios.com/

Hi John,
I don't know of any either, but given the definition of Class A, I
thought it wise to rule out the remote cut-off behaviour that *COULD*
provide a loophole to somebody fixed on disagreement, yes?
cheers,
Douglas

[Andre Jute]

On Oct 19, 3:50 pm, Multi-grid wrote:
overmatched to the Tannoys. It has around 16 to 18W in Class A alone.
I sometimes used mine for driving a bass bin, where its 100W in Class
A/B could sometimes come into play, at least theoretically (I'm not a
headbanger).

hey-Hey!!!,
An amp with maximum output happening with one phase of its PP set cut
off is *NOT* class A. A real class A amp has both phases conducting at
maximum power, and not from some variable pitch grid winding, remote
cut-off stuff either.

That Vellman amp is an AB, and barely so at that.
cheers,
Douglas

What are you on about, Dougles? I just told you, it is a class AB amp.
Class AB amps by definition have some class A output and the rest in
Class B. If you want an unadulterated Class A amp with a 100W output,
you're going to be paying real money, and if you're a snob who wants
it in SE, you're going to be paying Range Rover Vogue money. I know; I
built an 80W SE amp, which of course by definition ran only in Class
A. The Velleman is relatively inexpensive, very sturdy, very good
value amplifier kit from the most famous makers of all kinds of
electronic kits in the world. But its price will look a tip to a
doorman by the time you finish paying for a 100W Class A amp.

And what's that rubbish about "maximum output" anyway? By definition a
class AB amp's Class A output is at some lower power than maximum,
otherwise it would be a Class A amp, period. The whole point about a
Class AB amp is that most music is played where such an amp makes its
sweetest sounds, but that it has headroom for any contingency, though
you sacrifice a little something in quality when that headroom is
taken up.

If your taste is so refined that you must have nothing but Class A,
there are a bunch of designs for Class A amps on my netsite. And, for
the sake of completeness, my own favourite everyday amp is my own T113
"Triple Threat" design, which runs PP EL34s in triode and strictly in
Class A. But you'd need about 8 of those to get 100W...

You know an audiophool snob when he starts talking about "pure" Class
A...

Andre Jute
Visit Jute on Amps at http://members.lycos.co.uk/fiultra/
"wonderfully well written and reasoned information
for the tube audio constructor"
John Broskie TubeCAD & GlassWare
"an unbelievably comprehensive web site
containing vital gems of wisdom"
Stuart Perry Hi-Fi News & Record Review

[Multi-grid]

On Oct 20, 3:34 am, Andre Jute wrote:
On Oct 19, 3:50 pm, Multi-grid wrote:

overmatched to the Tannoys. It has around 16 to 18W in Class A alone.
I sometimes used mine for driving a bass bin, where its 100W in Class
A/B could sometimes come into play, at least theoretically (I'm not a
headbanger).

hey-Hey!!!,
An amp with maximum output happening with one phase of its PP set cut
off is *NOT* class A. A real class A amp has both phases conducting at
maximum power, and not from some variable pitch grid winding, remote
cut-off stuff either.

That Vellman amp is an AB, and barely so at that.
cheers,
Douglas

What are you on about, Dougles? I just told you, it is a class AB amp.
Class AB amps by definition have some class A output and the rest in
Class B.

No it doesn't, it has no power in Class A. That's why it is called an
AB amp. It is really simple.


If you want an unadulterated Class A amp with a 100W output,
you're going to be paying real money, and if you're a snob who wants
it in SE, you're going to be paying Range Rover Vogue money. I know; I
built an 80W SE amp, which of course by definition ran only in Class
A. The Velleman is relatively inexpensive, very sturdy, very good
value amplifier kit from the most famous makers of all kinds of
electronic kits in the world. But its price will look a tip to a
doorman by the time you finish paying for a 100W Class A amp.

I don't recall ever telling you what I wanted, or owned, or for that
matter what I've built. None of that has any bearing on your marketing-
based dafynishion of what you'd like an AB amp to be.


And what's that rubbish about "maximum output" anyway? By definition a
class AB amp's Class A output is at some lower power than maximum,
otherwise it would be a Class A amp, period.

Just because both of the finals are conducting does not mean it is
Class A. That is reserved for amps that keep both conducting *AT FULL
POWER*. Why *******ize the definition just because some marketing fool
likes says it's OK? A Class AB amp doesn't have any Class A output.
Both phases conducting does not make Class A....or is that too hard to
grasp?



The whole point about a
Class AB amp is that most music is played where such an amp makes its
sweetest sounds, but that it has headroom for any contingency, though
you sacrifice a little something in quality when that headroom is
taken up.

If your taste is so refined that you must have nothing but Class A,
there are a bunch of designs for Class A amps on my netsite.

I don't think I'll be considering any of those amps. Kinda off-the-
rack and boring.


And, for
the sake of completeness, my own favourite everyday amp is my own T113
"Triple Threat" design, which runs PP EL34s in triode and strictly in
Class A. But you'd need about 8 of those to get 100W...


You know an audiophool snob when he starts talking about "pure" Class
A...

Probably just somebody who knows how to use the language properly. You
can join the club anytime you wish to conduct yourself properly....and
leave it just as quickly.
cheers,
Douglas

[Andre Jute]

On Oct 19, 6:37 pm, Multi-grid wrote:
On Oct 20, 3:34 am, Andre Jute wrote:



On Oct 19, 3:50 pm, Multi-grid wrote:

overmatched to the Tannoys. It has around 16 to 18W in Class A alone.
I sometimes used mine for driving a bass bin, where its 100W in Class
A/B could sometimes come into play, at least theoretically (I'm not a
headbanger).

hey-Hey!!!,
An amp with maximum output happening with one phase of its PP set cut
off is *NOT* class A. A real class A amp has both phases conducting at
maximum power, and not from some variable pitch grid winding, remote
cut-off stuff either.

That Vellman amp is an AB, and barely so at that.
cheers,
Douglas

What are you on about, Dougles? I just told you, it is a class AB amp.
Class AB amps by definition have some class A output and the rest in
Class B.

No it doesn't, it has no power in Class A. That's why it is called an
AB amp. It is really simple.

If you want an unadulterated Class A amp with a 100W output,

you're going to be paying real money, and if you're a snob who wants
it in SE, you're going to be paying Range Rover Vogue money. I know; I
built an 80W SE amp, which of course by definition ran only in Class
A. The Velleman is relatively inexpensive, very sturdy, very good
value amplifier kit from the most famous makers of all kinds of
electronic kits in the world. But its price will look a tip to a
doorman by the time you finish paying for a 100W Class A amp.

I don't recall ever telling you what I wanted, or owned, or for that
matter what I've built. None of that has any bearing on your marketing-
based dafynishion of what you'd like an AB amp to be.



And what's that rubbish about "maximum output" anyway? By definition a
class AB amp's Class A output is at some lower power than maximum,
otherwise it would be a Class A amp, period.

Just because both of the finals are conducting does not mean it is
Class A. That is reserved for amps that keep both conducting *AT FULL
POWER*. Why *******ize the definition just because some marketing fool
likes says it's OK? A Class AB amp doesn't have any Class A output.
Both phases conducting does not make Class A....or is that too hard to
grasp?

The whole point about a

Class AB amp is that most music is played where such an amp makes its
sweetest sounds, but that it has headroom for any contingency, though
you sacrifice a little something in quality when that headroom is
taken up.

If your taste is so refined that you must have nothing but Class A,
there are a bunch of designs for Class A amps on my netsite.

I don't think I'll be considering any of those amps. Kinda off-the-
rack and boring.

And, for

the sake of completeness, my own favourite everyday amp is my own T113
"Triple Threat" design, which runs PP EL34s in triode and strictly in
Class A. But you'd need about 8 of those to get 100W...

You know an audiophool snob when he starts talking about "pure" Class A...

Probably just somebody who knows how to use the language properly. You
can join the club anytime you wish to conduct yourself properly....and
leave it just as quickly.

Yes, I see what this is about: another clown storming into RAT with a
mission to see me off. Thanks for coming, Dougles, but I don't think I
would care to belong to any club that lets you in.

cheers,
Douglas

[Multi-grid]

On Oct 20, 6:42 am, Andre Jute wrote:
On Oct 19, 6:37 pm, Multi-grid wrote:





On Oct 20, 3:34 am, Andre Jute wrote:

On Oct 19, 3:50 pm, Multi-grid wrote:

overmatched to the Tannoys. It has around 16 to 18W in Class A alone.
I sometimes used mine for driving a bass bin, where its 100W in Class
A/B could sometimes come into play, at least theoretically (I'm not a
headbanger).

hey-Hey!!!,
An amp with maximum output happening with one phase of its PP set cut
off is *NOT* class A. A real class A amp has both phases conducting at
maximum power, and not from some variable pitch grid winding, remote
cut-off stuff either.

That Vellman amp is an AB, and barely so at that.
cheers,
Douglas

What are you on about, Dougles? I just told you, it is a class AB amp.
Class AB amps by definition have some class A output and the rest in
Class B.

No it doesn't, it has no power in Class A. That's why it is called an
AB amp. It is really simple.

If you want an unadulterated Class A amp with a 100W output,

you're going to be paying real money, and if you're a snob who wants
it in SE, you're going to be paying Range Rover Vogue money. I know; I
built an 80W SE amp, which of course by definition ran only in Class
A. The Velleman is relatively inexpensive, very sturdy, very good
value amplifier kit from the most famous makers of all kinds of
electronic kits in the world. But its price will look a tip to a
doorman by the time you finish paying for a 100W Class A amp.

I don't recall ever telling you what I wanted, or owned, or for that
matter what I've built. None of that has any bearing on your marketing-
based dafynishion of what you'd like an AB amp to be.

And what's that rubbish about "maximum output" anyway? By definition a
class AB amp's Class A output is at some lower power than maximum,
otherwise it would be a Class A amp, period.

Just because both of the finals are conducting does not mean it is
Class A. That is reserved for amps that keep both conducting *AT FULL
POWER*. Why *******ize the definition just because some marketing fool
likes says it's OK? A Class AB amp doesn't have any Class A output.
Both phases conducting does not make Class A....or is that too hard to
grasp?

The whole point about a

Class AB amp is that most music is played where such an amp makes its
sweetest sounds, but that it has headroom for any contingency, though
you sacrifice a little something in quality when that headroom is
taken up.

If your taste is so refined that you must have nothing but Class A,
there are a bunch of designs for Class A amps on my netsite.

I don't think I'll be considering any of those amps. Kinda off-the-
rack and boring.

And, for

the sake of completeness, my own favourite everyday amp is my own T113
"Triple Threat" design, which runs PP EL34s in triode and strictly in
Class A. But you'd need about 8 of those to get 100W...

You know an audiophool snob when he starts talking about "pure" Class A...

Probably just somebody who knows how to use the language properly. You
can join the club anytime you wish to conduct yourself properly....and
leave it just as quickly.

Yes, I see what this is about: another clown storming into RAT with a
mission to see me off. Thanks for coming, Dougles, but I don't think I
would care to belong to any club that lets you in.



cheers,
Douglas- Hide quoted text -

- Show quoted text -- Hide quoted text -

- Show quoted text -

hey-Hey!!!,
Well Andre, you can imagine my mission to be what ever it you want.
Again, that has no bearing what so ever on your mis-use of the
definition. Please stay on topic if you'd be so kind. Quit clouding
the issue please.

Do people go 'storming into RAT with a mission to see me off' alot
lately? Are you paranoid or something? Where would you get such an
idea?

I'll type slowly so you can understand it, this club I referred to
only requires its members to use accepted audio definitions and terms
properly. Of course it doesn't really exist, save for in
metaphore...but an accomplished writer like you would know all this,
right?

While you're at it, a schematic of your 80W SE amp would be nice to
look at.
cheers,
Douglas

[sparky]

On Oct 19, 7:27 am, Andre Jute wrote:
On Oct 19, 12:11 am, "Iain Churches" wrote:

"Andre Jute" wrote

Real tubies build real valve amp kits, like
my Velleman K4000, three EL34 per side for 18W in Class A and 101W in
Class B (measured, they claim only 16/96W). Now that is an amp that
leaves hairy footprints.

Interesting you should mention the Velleman. It is indeed a good sounding
amp. It is a long time since I have seen a K4000, but I seem to recollect
it had four EL34's in push pull parallel per side.

PPP.

It seems as though the K4000 is discontinued.

Mine is ancient. Early to mid-1990s, at a guess, without looking up
the reviews I wrote of it.

I listened to a 4040 not too long ago, with a pair of splendid Tannoy
Canterbury
SE speakers. Very pleasing indeed. The amp was running far below its full
power potential.

Quite a bizarre thing to say, I suppose, but the Velleman is probably
overmatched to the Tannoys. It has around 16 to 18W in Class A alone.
I sometimes used mine for driving a bass bin, where its 100W in Class
A/B could sometimes come into play, at least theoretically (I'm not a
headbanger).

The noise floor was exceptionally low. Later, a quick
look on the bench revealed the noise floor to be 100µV, so a
SNR of 105dB and at 96W, the THD was only 0.1%

It depends on your outlook whether you view the Velleman K40x0 as that
rare thing, a perfect all-round amp -- or as a perfectly schizophrenic
amp: on the one hand superbly well designed and good-sounding,
escpecially in that very hefty Class A segment, a delicate match to
ESL-63, on the other hand a brutish bass thumper on demand. As an all-
round amp of excellent quality and durability it is of course a very
great bargain at the price.

The Belgians know how to make more than just chocolates:-)

We used to make a round trip of 50 miles to buy Belgian chocolates in
Cork...

Regards
Iain

Andre Jute
Visit Jute on Amps athttp://members.lycos.co.uk/fiultra/
"wonderfully well written and reasoned information
for the tube audio constructor"
John Broskie TubeCAD & GlassWare
"an unbelievably comprehensive web site
containing vital gems of wisdom"
Stuart Perry Hi-Fi News & Record Review

Of all the decent amps out there why would you pick something like
This?

[Iain Churches[_2_]]

"Andre Jute" wrote in message
oups.com...
On Oct 19, 12:11 am, "Iain Churches" wrote:

The noise floor was exceptionally low. Later, a quick
look on the bench revealed the noise floor to be 100µV, so a
SNR of 105dB and at 96W, the THD was only 0.1%

It depends on your outlook whether you view the Velleman K40x0 as that
rare thing, a perfect all-round amp --

(snip)

Oh,. I don't think it is anywhere near that!
I regard it as a good-sounding DIY project, no more.
The fact that the tube sockets are mounted on the PCB
really put me off.

I have a Radford STA 100. So no contest.

Iain

[Jon Yaeger]

(snip)

Oh,. I don't think it is anywhere near that!
I regard it as a good-sounding DIY project, no more.
The fact that the tube sockets are mounted on the PCB
really put me off.

I have a Radford STA 100. So no contest.

Iain



I owned one that another fellow put together. I remember replacing some of
the 10 ohm resistors because of excessive cathode current draw.

It was a nice looking amp, with plenty of power. The PCBs were a turn-off,
but not a killer for me (Hey, if you want to have some REAL fun, do
component-level work on an Audio Research D-70. What a nightmare to repair!)

In my continuing search for the holy grail of sound, that amp went to a new
owner. To my ears, the sound was kind of harsh for a tube amp, and lacking
excitement.

I agree that it is "a good-sounding DIY project."

Jon

[Iain Churches[_2_]]

"Jon Yaeger" wrote in message
...

I owned one that another fellow put together. I remember replacing some
of
the 10 ohm resistors because of excessive cathode current draw.

It was a nice looking amp, with plenty of power. The PCBs were a turn-off,
but not a killer for me (Hey, if you want to have some REAL fun, do
component-level work on an Audio Research D-70. What a nightmare to
repair!)

In my continuing search for the holy grail of sound, that amp went to a
new
owner. To my ears, the sound was kind of harsh for a tube amp, and
lacking
excitement.

I agree that it is "a good-sounding DIY project."

And, in that respect, if it does something to light the spark
of interest in tube audio, then it has served a very useful purpose.

Iain

[Andre Jute]

On Oct 21, 7:48 am, "Iain Churches" wrote:
"Andre Jute" wrote in message

oups.com...
On Oct 19, 12:11 am, "Iain Churches" wrote:

The noise floor was exceptionally low. Later, a quick
look on the bench revealed the noise floor to be 100µV, so a
SNR of 105dB and at 96W, the THD was only 0.1%

It depends on your outlook whether you view the Velleman K40x0 as that
rare thing, a perfect all-round amp --

It's all opinion. Some opinions are informed by relevant experience
and therefore more valuable. Some opinions are informed by nothing but
street corner gossip or personal animosity and are therefore
worthless.

Oh,. I don't think it is anywhere near that!
I regard it as a good-sounding DIY project, no more.
The fact that the tube sockets are mounted on the PCB
really put me off.

I have a Radford STA 100. So no contest.

And I have a Quad II. No contest, to my mind at least; it depends what
you want to measure and hear. Except that the Quad II doesn't put out
100W. Let's compare apples with apples, not with gilded plums, mmm?

I could compare the Velleman K4000 100W with a bunch of other kits I
have built and used extensively: Arion Adonis PP 5581 20W, Audio
Innovations Classic Stereo 25 PP EL34 25W, Triode Supply Japan Miyabe
300B SEPP 16W, etc, etc, and in no instance would it be comparing
apples with apples, for the good and simple reason that none of them
have 100W. In that the Velleman K40*0 stands alone, and gives the
beginner versatility to use the most grossly insensitive bookshelf
speakers to get real oomph on any music whatsoever. I could have
chosen any of the amps listed, or any of the other kits I have built,
including some I don't list because they have less than 10W, and said
they're fine on some aspect (or even the best) but, while all of them
have served me very well indeed, none of them can be put up against
the Velleman without admitting some handicap in some perfectly common
everyday use for an identifiable group of users.

I might add that my favourite among that lot is the AI, which is a
gentleman's amp, never intrusive; an amp you can play 14 hours every
day and never find fault with. I find the Velleman far too analytical
for my taste but that is because it is so accurate, a characteristic
many value. But, to illustrate once more that all this is relative to
usage and opinion, I play mainly chamber music at low volume;
symphonic or other "big" music played on insensitive speakers
*requires* a big amp. If I were into heavy metal or whatever the
current fave of the loud set is called, I wouldn't touch any of my
favourite amps for chamber music -- they'd all be less than convincing
-- I'd go straight to the Velleman and acoustic overload heaven.

By the way, the Velleman K40*0 is eminently tweakable. On my old
netsite I had an entire big section devoted to altering the factory
spec to make it sound like anything you wanted it to sound like. The
"harshness" Jon Yaeger objects to, for instance, was just a matter of
swapping out a ceramic (! now that's an excess of engineering...) cap
for a film cap; you would of course sacrifice a little of the
excellent noise spec (which was why the designer put it in there) but
might consider the loss worthwhile to gain precisely the sound you
want. I'm amazed that Yaeger doesn't know that.

As for the snobbery of demanding point to point wiring on kits, go
right ahead: you'll be helping to kill the hobby off faster than is
necessary. In my experience eliminating the PCB, or insisting on
sockets mounted to the chassis, just about triples the price of the
kit, and ensures that the successful assembly rate is halved.
(Suppliers who give a completion guarantee, or who provide a
handholding service, keep very good records of these matters! Or you
can read between the lines in the instructions and on the sites of
those who sell PTP kits how fed up they are with seeing time and
profits dribble away in support to eejits who cannot follow simple
instructions.)

If you insist on hardwiring, nothing stops you buying a Velleman K40*0
kit, or any other kit with a chassis, to get the design and all the
parts, and simply drilling the cover to hold sockets for the tubes and
then fitting the components to tag strips you supply. Nor is there any
secret to designing a PCB construction properly for heat management:
either ascertain that the kit has ceramic standoffs for power tubes
and resistors as standard, or add them yourself. I'm really amazed at
discovering DIYers who brag about their craftsmanship, then complain
about an amp because it is designed to be built on a PCB: if you don't
like it, change it!

Iain

For those who need or want a 100W and prefer tubes, the Velleman K40x0
is unique, zero competition that I know about.

I don't see much point in nitpicking commercial amps against
irrelevant self-proclaimed "standards"; the test is whether the thing
works in the hands of owners, and the K40*0 worked fine for a decade
and more in my hands. We've already had a bunch of clowns in this
thread condemning one of the most succesful commercial amps in the
world *without ever seeing one or hearing it*. That sort of street
corner gossip repeated as gospel is what trashes the reputation of
RAT, not putting down the thieves of intellectual rights or netbullies
and netstalkers -- on the contrary, it is toleration and protection of
such people that trashes our reputation.

Andre Jute
Visit Jute on Amps at http://members.lycos.co.uk/fiultra/
"wonderfully well written and reasoned information
for the tube audio constructor"
John Broskie TubeCAD & GlassWare
"an unbelievably comprehensive web site
containing vital gems of wisdom"
Stuart Perry Hi-Fi News & Record Review

[Phread]

"Andre Jute" wrote in message oups.com...
On Oct 21, 7:48 am, "Iain Churches" wrote:
"Andre Jute" wrote in message

oups.com...
On Oct 19, 12:11 am, "Iain Churches" wrote:

The noise floor was exceptionally low. Later, a quick
look on the bench revealed the noise floor to be 100µV, so a
SNR of 105dB and at 96W, the THD was only 0.1%

It depends on your outlook whether you view the Velleman K40x0 as that
rare thing, a perfect all-round amp --

It's all opinion. Some opinions are informed by relevant experience
and therefore more valuable. Some opinions are informed by nothing but
street corner gossip or personal animosity and are therefore
worthless.

Oh,. I don't think it is anywhere near that!
I regard it as a good-sounding DIY project, no more.
The fact that the tube sockets are mounted on the PCB
really put me off.

I have a Radford STA 100. So no contest.

And I have a Quad II. No contest, to my mind at least; it depends what
you want to measure and hear. Except that the Quad II doesn't put out
100W. Let's compare apples with apples, not with gilded plums, mmm?

I could compare the Velleman K4000 100W with a bunch of other kits I
have built and used extensively: Arion Adonis PP 5581 20W, Audio
Innovations Classic Stereo 25 PP EL34 25W, Triode Supply Japan Miyabe
300B SEPP 16W, etc, etc, and in no instance would it be comparing
apples with apples, for the good and simple reason that none of them
have 100W. In that the Velleman K40*0 stands alone, and gives the
beginner versatility to use the most grossly insensitive bookshelf
speakers to get real oomph on any music whatsoever. I could have
chosen any of the amps listed, or any of the other kits I have built,
including some I don't list because they have less than 10W, and said
they're fine on some aspect (or even the best) but, while all of them
have served me very well indeed, none of them can be put up against
the Velleman without admitting some handicap in some perfectly common
everyday use for an identifiable group of users.

I might add that my favourite among that lot is the AI, which is a
gentleman's amp, never intrusive; an amp you can play 14 hours every
day and never find fault with. I find the Velleman far too analytical
for my taste but that is because it is so accurate, a characteristic
many value. But, to illustrate once more that all this is relative to
usage and opinion, I play mainly chamber music at low volume;
symphonic or other "big" music played on insensitive speakers
*requires* a big amp. If I were into heavy metal or whatever the
current fave of the loud set is called, I wouldn't touch any of my
favourite amps for chamber music -- they'd all be less than convincing
-- I'd go straight to the Velleman and acoustic overload heaven.

By the way, the Velleman K40*0 is eminently tweakable. On my old
netsite I had an entire big section devoted to altering the factory
spec to make it sound like anything you wanted it to sound like. The
"harshness" Jon Yaeger objects to, for instance, was just a matter of
swapping out a ceramic (! now that's an excess of engineering...) cap
for a film cap; you would of course sacrifice a little of the
excellent noise spec (which was why the designer put it in there) but
might consider the loss worthwhile to gain precisely the sound you
want. I'm amazed that Yaeger doesn't know that.

As for the snobbery of demanding point to point wiring on kits, go
right ahead: you'll be helping to kill the hobby off faster than is
necessary. In my experience eliminating the PCB, or insisting on
sockets mounted to the chassis, just about triples the price of the
kit, and ensures that the successful assembly rate is halved.
(Suppliers who give a completion guarantee, or who provide a
handholding service, keep very good records of these matters! Or you
can read between the lines in the instructions and on the sites of
those who sell PTP kits how fed up they are with seeing time and
profits dribble away in support to eejits who cannot follow simple
instructions.)

If you insist on hardwiring, nothing stops you buying a Velleman K40*0
kit, or any other kit with a chassis, to get the design and all the
parts, and simply drilling the cover to hold sockets for the tubes and
then fitting the components to tag strips you supply. Nor is there any
secret to designing a PCB construction properly for heat management:
either ascertain that the kit has ceramic standoffs for power tubes
and resistors as standard, or add them yourself. I'm really amazed at
discovering DIYers who brag about their craftsmanship, then complain
about an amp because it is designed to be built on a PCB: if you don't
like it, change it!

Iain

For those who need or want a 100W and prefer tubes, the Velleman K40x0
is unique, zero competition that I know about.

I don't see much point in nitpicking commercial amps against
irrelevant self-proclaimed "standards"; the test is whether the thing
works in the hands of owners, and the K40*0 worked fine for a decade
and more in my hands. We've already had a bunch of clowns in this
thread condemning one of the most succesful commercial amps in the
world *without ever seeing one or hearing it*. That sort of street
corner gossip repeated as gospel is what trashes the reputation of
RAT, not putting down the thieves of intellectual rights or netbullies
and netstalkers -- on the contrary, it is toleration and protection of
such people that trashes our reputation.

Horse****, Andre. It isn't the reputation of RAT that's trashed, it's the
atmosphere that people have been fleeing. That atmosphere has been
trashed by your relentless personal attacks on everyone you can find
even the slightest reason to go after.

But it's OK; pretty soon you and your sock puppets will have this place
all to yourselves. You'll be able to launch devastating attacks on your
sock puppets every day and no one will complain unless you do it for
them.

He he, Andre, what a horse's ass you are.

Andre Jute
Visit Jute on Amps at http://members.lycos.co.uk/fiultra/
"wonderfully well written and reasoned information
for the tube audio constructor"
John Broskie TubeCAD & GlassWare
"an unbelievably comprehensive web site
containing vital gems of wisdom"
Stuart Perry Hi-Fi News & Record Review

[Multi-grid]

I don't see much point in nitpicking commercial amps against
irrelevant self-proclaimed "standards"; the test is whether the thing
works in the hands of owners, and the K40*0 worked fine for a decade
and more in my hands. We've already had a bunch of clowns in this
thread condemning one of the most succesful commercial amps in the
world *without ever seeing one or hearing it*. That sort of street
corner gossip repeated as gospel is what trashes the reputation of
RAT, not putting down the thieves of intellectual rights or netbullies
and netstalkers -- on the contrary, it is toleration and protection of
such people that trashes our reputation.

Andre Jute


I'll second Phread, it is the personal attacking that makes this place
less-than. If you'd examine the history, RAT was a reasonable going
concern until the Jute v. Magnetquest war. Seems Andre was unable to
make a legitimate criticism of Mikey stick.

So then Andre, you mention an AB amp having A power, you reference an
80W SE amp, claim an off the rack Vellman kit is brilliant, and then
attack anybody who'd have the guts to say you've over reached. Even
with poor S/N ratio there is still signal. Let's see some from you.
cheers,
Douglas

[mick]

On Mon, 22 Oct 2007 13:50:47 -0700, Multi-grid wrote:


snip

So then Andre, you mention an AB amp having A power, you reference an
80W SE amp, claim an off the rack Vellman kit is brilliant, and then
attack anybody who'd have the guts to say you've over reached. Even with
poor S/N ratio there is still signal. Let's see some from you. cheers,


Surely though, a class AB amp such as the Vellman *is* running in class A
up to the point where one output device starts to turn off isn't it? The
changeover to class B happens at that point and is dependent on the
quiescent current in the outputs.

A true class A amp is only a special case of the normal AB class. It's
just that it clips symmetrically instead of moving smoothly into class
B. ;-)

--
Mick (Working in a M$-free zone!)
Web: http://www.nascom.info http://mixpix.batcave.net

[Multi-grid]

Surely though, a class AB amp such as the Vellman *is* running in class A
up to the point where one output device starts to turn off isn't it?
--
Mick (Working in a M$-free zone!)
Web:http://www.nascom.info http://mixpix.batcave.net

Nope, not a chance. That both tubes are conducting does not mean it is
A. Have some respect... AB amps don't have any A power, that is why
there is a seperate classification.
cheers,
Douglas

[Andre Jute]

On Oct 22, 2:33 pm, mick wrote:
On Mon, 22 Oct 2007 13:50:47 -0700, Multi-grid wrote:

snip

So then Andre, you mention an AB amp having A power, you reference an
80W SE amp, claim an off the rack Vellman kit is brilliant, and then
attack anybody who'd have the guts to say you've over reached. Even with
poor S/N ratio there is still signal. Let's see some from you. cheers,

Who is this fellow "Multi-grid", and why is he addressing me?

Surely though, a class AB amp such as the Vellman *is* running in class A
up to the point where one output device starts to turn off isn't it? The
changeover to class B happens at that point and is dependent on the
quiescent current in the outputs.

I would have thought anyone with a handle like "Multi-grid" would have
taken that sort of basic tube knowledge from the teat. Mind you, I
remember when Ron Bales wanted us here on RAT to give everyone who
claimed a "tubie-handle" a test of tube knowledge to ensure they don't
give a respectable hobby a bad name by wielding their ignorance like
clubs. That was about 1998. Looks like this "Multi-grid" fellow is a
prime candidate for the Bales Test.

A true class A amp is only a special case of the normal AB class. It's
just that it clips symmetrically instead of moving smoothly into class
B. ;-)

It is beneath my dignity to rise to such provocation -- sniff. A Class
AB amp is a compromised Class A amp, and it probably requires negative
feedback too to work even acceptably. A properly designed Class A amp
never clips because the operating parameters were so chosen that it
runs out of signal from the intended source before it can clip (that
is one reason why the design instructions on my netsite feature the
*design center* process so heavily). It is only "engineers" who
"design" amps to hog the maximum power from each tube who even need a
concept like clipping; for sane tubies it is obsolete terminology.

--
Mick (Working in a M$-free zone!)
Web:http://www.nascom.infohttp://mixpix.batcave.net

Andre Jute
Our legislators managed to criminalize fox-hunting and smoking; when
will they get off their collective fat backside and criminalize
negative feedback? It is clearly consumed only by thickoes.