Does anyone here have experience using DJ amplifiers in their home
theater? Is it recommended?

Many DJ amplifiers seem to offer good bang for the buck. One thing I
notice is that few provide rms power ratings. Should I assume that
the power rating list is max power and that the actual rms is about
1/2 of that amount?

Also, if DJ amplifiers are a feasible approach, what is the best way
to connect them to RCA outputs? Do adapters exist for this?

Thanks,

bguidry

"bsguidry" wrote in message
om...
Does anyone here have experience using DJ amplifiers in their home
theater? Is it recommended?

Many DJ amplifiers seem to offer good bang for the buck. One thing I
notice is that few provide rms power ratings. Should I assume that
the power rating list is max power and that the actual rms is about
1/2 of that amount?

Also, if DJ amplifiers are a feasible approach, what is the best way
to connect them to RCA outputs? Do adapters exist for this?

In my experience, they lack clarity compared to good home audio equipment.

Sound reinforcement equipment is intended to sound loud. The circuits are
simple.

Here it's important to distinguish with studio amps. There are many studio
amplifiers of exceptional quality.
Since both typically have balanced inputs, and many have fans, it can be
hard to tell the difference.
Hafler and Crown make very high quality amps.
And Crown amps are used in expensive sound reinforcement apps.

"bsguidry" wrote in message
om

Does anyone here have experience using DJ amplifiers in their home
theater?

Definitely.

Is it recommended?

It's recommended if you do it right, and are willing to make suitable
adaptations.

One thing to watch out for is the fact that many of these amps have fans.
Amps with fans generally aren't such a good idea if you keep them near your
listening location. They're not much of a problem if you keep your amps in a
closet or outside the listening room.

Many DJ amplifiers seem to offer good bang for the buck.

You still get what you pay for, but you're buying out of a more pragmatic
marketplace.

One thing I notice is that few provide rms power ratings.

You must be looking at junk, or not finding the right ratings lists.

Good brands to look at include QSC, Hafler, and Crown. If you surf the
vendor web sites, you'll find very detailed RMS power specs.

Should I assume that
the power rating list is max power and that the actual rms is about
1/2 of that amount?

Better yet, surf the web for the actual professional spec sheets. Forget
what you see in flyers and on tags in dealers.

Also, if DJ amplifiers are a feasible approach, what is the best way
to connect them to RCA outputs?

If you want to do it right, you make some custom cables or have them made.
If you want expeditious, but useful results, you just pick up some mono-1/4"
to RCA adaptors at Radio Shack.

Do adapters exist for this?

For sure. The Radio Shack adaptors are 2 for under $4, last time I looked.

In article ,
says...
"bsguidry" wrote in message
om

Does anyone here have experience using DJ amplifiers in their home
theater?
One thing I notice is that few provide rms power ratings.

You must be looking at junk, or not finding the right ratings lists.

Good brands to look at include QSC, Hafler, and Crown. If you surf the
vendor web sites, you'll find very detailed RMS power specs.

I suspect the OP is thinking in terms of DJ brands like
Gemini, American DJ, etc. Not the Pro-grade brands you're
mentioning.


--
Mark

The truth as I perceive it to be.
Your perception may be different.

Triple Z is spam control.

"Mark" wrote in message
th.net

In article ,
says...

"bsguidry" wrote in message
om

Does anyone here have experience using DJ amplifiers in their home
theater?
One thing I notice is that few provide rms power ratings.

You must be looking at junk, or not finding the right ratings lists.

Good brands to look at include QSC, Hafler, and Crown. If you surf
the vendor web sites, you'll find very detailed RMS power specs.

I suspect the OP is thinking in terms of DJ brands like
Gemini, American DJ, etc. Not the Pro-grade brands you're
mentioning.

Could be.

"Arny Krueger" wrote in message
...
"bsguidry" wrote in message
om

Does anyone here have experience using DJ amplifiers in their home
theater?

Definitely.

Is it recommended?

It's recommended if you do it right, and are willing to make suitable
adaptations.

One thing to watch out for is the fact that many of these amps have fans.
Amps with fans generally aren't such a good idea if you keep them near
your
listening location. They're not much of a problem if you keep your amps in
a
closet or outside the listening room.

Many DJ amplifiers seem to offer good bang for the buck.

You still get what you pay for, but you're buying out of a more pragmatic
marketplace.

One thing I notice is that few provide rms power ratings.

You must be looking at junk, or not finding the right ratings lists.

Good brands to look at include QSC, Hafler, and Crown. If you surf the
vendor web sites, you'll find very detailed RMS power specs.

Take QSC off the list. It's a testament to Arny's hearing difficulties.
Othewise, I concur.

"Robert Morein" wrote in message ...
"Arny Krueger" wrote in message
...
"bsguidry" wrote in message
om

Does anyone here have experience using DJ amplifiers in their home
theater?

Definitely.

Is it recommended?

It's recommended if you do it right, and are willing to make suitable
adaptations.

One thing to watch out for is the fact that many of these amps have fans.
Amps with fans generally aren't such a good idea if you keep them near
your
listening location. They're not much of a problem if you keep your amps in
a
closet or outside the listening room.

Many DJ amplifiers seem to offer good bang for the buck.

You still get what you pay for, but you're buying out of a more pragmatic
marketplace.

One thing I notice is that few provide rms power ratings.

You must be looking at junk, or not finding the right ratings lists.

Good brands to look at include QSC, Hafler, and Crown. If you surf the
vendor web sites, you'll find very detailed RMS power specs.

Take QSC off the list. It's a testament to Arny's hearing difficulties.
Othewise, I concur.

I've definitely consider QSC and Crown, however, I've not encountered
Hafler very often in my searching. Other brands that caught my
attention were Nady, Samson, Peavey, and Behringer. The fan noise
could be a problem as suggested. Since the concensus here seems to
indicate going with the more pricey Crown or Hafler amplifiers, I
think I will revert my focus back to obtaining a higher powerered
Carver amplifier. I'm currently using one rated at 175watts rms X 2
at 4 ohms. I love the look of the Carvers with the two analog power
meters on the front. I guess I'll keep scanning Ebay for good finds
on these. Thanks for all the feedback to this post and two my
previous posts about my Adire Tempest project.

bguidry

"bsguidry" wrote in message
om
"Robert Morein" wrote in message
...
"Arny Krueger" wrote in message
...
"bsguidry" wrote in message
om

Does anyone here have experience using DJ amplifiers in their home
theater?

Definitely.

Is it recommended?

It's recommended if you do it right, and are willing to make
suitable adaptations.

One thing to watch out for is the fact that many of these amps have
fans. Amps with fans generally aren't such a good idea if you keep
them near your listening location. They're not much of a problem if
you keep your
amps in a closet or outside the listening room.

Many DJ amplifiers seem to offer good bang for the buck.

You still get what you pay for, but you're buying out of a more
pragmatic marketplace.

One thing I notice is that few provide rms power ratings.

You must be looking at junk, or not finding the right ratings lists.

Good brands to look at include QSC, Hafler, and Crown. If you surf
the vendor web sites, you'll find very detailed RMS power specs.

Take QSC off the list. It's a testament to Arny's hearing
difficulties. Otherwise, I concur.

Ask Morein about his power amp DBTs. Then take a few of mine by downloading
files from http://www.pcabx.com/product/amplifiers/index.htm . BTW you can
hear audible differences between amps with some of these files, but the
test circumstances will be instructive.

I've definitely consider QSC and Crown, however, I've not encountered
Hafler very often in my searching.

One sees Haflers in a lot of control and mastering rooms, since we're
talking pro audio.

Other brands that caught my
attention were Nady, Samson, Peavey, and Behringer.

Other than Peavey, you're talking bottom-feeder specials. Nevertheless there
are some new Behringers (said to be essentially QSC clones, who'd a
figured?) that have more than a few people excited.

The fan noise
could be a problem as suggested. Since the consensus here seems to
indicate going with the more pricey Crown or Hafler amplifiers, I
think I will revert my focus back to obtaining a higher powerered
Carver amplifier.

Your typical Crown, QSC, or Hafler would probably bury a Carver when it
comes to difficult loads.

I'm currently using one rated at 175watts rms X 2 at 4 ohms.

Consider the fact that your typical Crown, QSC or Hafler has 4-ohm bridged
ratings. That correspond to a 2 ohm load.

I love the look of the Carvers with the two analog power
meters on the front.

I'd trade a really sensitive, accurate clipping light for fancy meters in a
heart beat.

"Arny Krueger" wrote

Since the consensus here seems to
indicate going with the more pricey Crown or Hafler
amplifiers, I think I will revert my focus back to
obtaining a higher powerered Carver amplifier.

Your typical Crown, QSC, or Hafler would probably
bury a Carver when it comes to difficult loads.

"would probably"... how would you know, mr.
no-empirical-experiences? Krell, Levinson and others
could be said to “bury” your biased picks, too.

I'm currently using one rated at 175watts rms X 2 at 4 ohms.

Consider the fact that your typical Crown, QSC or Hafler has
4-ohm bridged ratings. That correspond to a 2 ohm load.

Why is that relevant (bridging) to the poster’s
application/needs? RMS load rating is not
the major determinant in high fidelity reproduction.
It is only one factor of many to consider.

I love the look of the Carvers with the two analog power
meters on the front.

I'd trade a really sensitive, accurate clipping light for fancy
meters in a heart beat.

Quack, quack, quack...

"bsguidry" wrote in message
om...
[snip]
, or not finding the right ratings lists.

Good brands to look at include QSC, Hafler, and Crown. If you surf the
vendor web sites, you'll find very detailed RMS power specs.

Take QSC off the list. It's a testament to Arny's hearing difficulties.
Othewise, I concur.

I've definitely consider QSC and Crown, however, I've not encountered
Hafler very often in my searching.

David Hafler invented the Ultralinear tube circuit, which firmly enshrines
him in the audio pantheon of greats. He became chief engineer of Dynaco, and
went on to start Hafler. His second product was the DH-200, the world's
first MOSFET audio amplifier. At the time, this amp was regarded as a
price/performance breakthrough. Unassuming in appearance, it has massive
heatsinks with very plain metalwork. It was followed by some extremely good
preamps, and more MOSFET amps, some of which had a new circuit, the
Excelinear.

MOSFET amps are the most durable of all solid state amplifiers. They can
drive any load without output damage, and if you're reasonably lucky, they
will survive a dead short. The MOSFET transistor is now ubiquitous in power
switching applications because of it's ruggedness.

The sound of the traditional MOSFET circuit has both followers and
detractors, to which I add my personal observation that they complement
metal dome tweeters very well, but are not as good with fabric types.
Another MOSFET circuit developed by Jim Strickland, founder of Acoustat,
provides a different kind of sound that compliments fabric tweeters. I use
both types of amplifiers in my systems, depending upon the speakers they
match. At the time of it's introduction, the Acoustat TNT-200 was featured
on the cover of Audio Magazine, and it was regarded by many, at that time,
as raising the bar for clarity and detail in reproduction.

When Rockford bought Hafler and Acoustat, they chose -- unfortunately, in my
opinion, to preserve only one amplifier technology. Strickland's original
design was hardened -- the original design had vulnerabilities that had
nothing to do with output load -- and launched the 9000 series, and the P
series professional amps. These are astonishingly small, extremely high
quality amplifiers that are far tougher than the typical professional unit.
Because they use MOSFETs, they have no relays or fuses, and in my opinion,
have MUCH higher fidelity than the QSC units. Both types of Haflers are
common in studios, the XL-600 being one of t he most prized units. I have a
P3000.

Every once in a while, I find something really remarkable, or at least
remarkable for the price. I also use the Parasound HCA-2200ii bipolar amp. I
have found the Yamaha bipolar M series to have merit, though the build
quality is not in the class of an American amplifier. Nelson Pass's
Threshold amplifiers can be found in some Nakamichi receivers, and are quite
a pleasant surprise. B&K amplifiers use the traditional MOSFET circuit, with
exceptional build quality. I do not particularly enjoy ADCOM MOSFET amps,
though the build quality is very high.

I found the sound of Rotel, touted by various audio magazines, to be
disappointingly shrill.

The QSC is muddy. It's performance is a throwback to the bipolar amplifiers
of the late 70's and early 80's.

"Powell" wrote in message

"Arny Krueger" wrote

Since the consensus here seems to
indicate going with the more pricey Crown or Hafler
amplifiers, I think I will revert my focus back to
obtaining a higher powerered Carver amplifier.

Your typical Crown, QSC, or Hafler would probably
bury a Carver when it comes to difficult loads.

"would probably"... how would you know, Mr. no-empirical-experiences?

Given the rather conspicious reliable evidence that I've got considerable
emperical experience with these and many other amps, one is tempted to ask
what the heck are you ranting about, Powell?

Krell, Levinson and others
could be said to "bury" your biased picks, too.

True, there's no theoretical limit to how much an amp can be underrated.

I'm currently using one rated at 175watts rms X 2 at 4 ohms.

Consider the fact that your typical Crown, QSC or Hafler has
4-ohm bridged ratings. That correspond to a 2 ohm load.

Why is that relevant (bridging) to the poster's
application/needs?

See former comments about "difficult loads" and comment just above about "2
ohm load".

RMS load rating is not
the major determinant in high fidelity reproduction.

So Powell, does that mean that your main system with speakers has power amps
rated at 100 milliwatts, RMS? Of course not. There's at least a loose
relationship between RMS power ratings and ability to drive speakers to
useful volume levels. In fact there's no other spec that is vastly
different, and more relevant.

It is only one factor of many to consider.

Name a commonly-used amplifier spec that is vastly different and also a
better predictor of an amps ability to drive speakers to satisfying levels.

I love the look of the Carvers with the two analog power
meters on the front.

I'd trade a really sensitive, accurate clipping light for fancy
meters in a heart beat.

Quack, quack, quack...

So Powell, does that mean that given the chance, you took the fancy meters
that impress visiting-firemen and small children?

"Robert Morein" wrote in message


The QSC is muddy. It's performance is a throwback to the bipolar
amplifiers of the late 70's and early 80's.

Thus says a guy who would apparently die ignorant and inexperienced rather
than do a level-matched, time-synched bias-controlled listening test.

"Arny Krueger" wrote in message
...
"Robert Morein" wrote in message


The QSC is muddy. It's performance is a throwback to the bipolar
amplifiers of the late 70's and early 80's.

Thus says a guy who would apparently die ignorant and inexperienced rather
than do a level-matched, time-synched bias-controlled listening test.

Thusw says an engineer who has questionable hearing.

"Robert Morein" wrote in message

"Arny Krueger" wrote in message
...
"Robert Morein" wrote in message


The QSC is muddy. It's performance is a throwback to the bipolar
amplifiers of the late 70's and early 80's.

Thus says a guy who would apparently die ignorant and inexperienced
rather than do a level-matched, time-synched bias-controlled
listening test.

Thusw says an engineer who has questionable hearing.

Tell us why your hearing is unimpeachible, Morein.

"Robert Morein" wrote in message
...
MOSFET amps are the most durable of all solid state amplifiers.
They can
drive any load without output damage, and if you're reasonably
lucky, they
will survive a dead short. The MOSFET transistor is now
ubiquitous in power
switching applications because of it's ruggedness.

Really? That's an exceptional claim. Why do you claim MOSFETs
amps are any more durable than a bipolar output stage amp?

Bipoloar transistors do exihibit secondary breakdown and current
hogging/thermal runaway. However, in a competent design both
issues can be firmly addressed. Reliability and durability
should be no worse than a MOSFET amp.

The reason MOSFET output stages are ubiquitous these days is cost
and availability.

"Rusty Boudreaux" wrote in message


"Robert Morein" wrote in message
...

MOSFET amps are the most durable of all solid state amplifiers. They
can drive any load without output damage, and if you're reasonably
lucky, they will survive a dead short. The MOSFET transistor is now
ubiquitous in power switching applications because of it's
ruggedness.

Really? That's an exceptional claim. Why do you claim MOSFETs
amps are any more durable than a bipolar output stage amp?

It is true that MOSFET devices sometimes have greater inherent durability,
while BJT devices MUST be used with carefully-engineered protection
circuitry.

Bipoloar transistors do exhibit secondary breakdown and current
hogging/thermal runaway. However, in a competent design both
issues can be firmly addressed. Reliability and durability
should be no worse than a MOSFET amp.

Agreed. Morein doesn't seem to understand the kind of tough use and abuse
that well-engineered BJT amps routinely tolerate and even thrive on, with
appropriate circuit design. It took a while for engineers to figure out how
to protect BJT output stages from use and abuse, but that was all over
decades ago.

The reason MOSFET output stages are ubiquitous these days is cost
and availability.

Actually, it's BJT output stages that are ubiquitous but you've got the
reasons right - cost and availability.

"Arny Krueger" wrote

"Arny Krueger" wrote

Since the consensus here seems to
indicate going with the more pricey Crown or Hafler
amplifiers, I think I will revert my focus back to
obtaining a higher powerered Carver amplifier.

Your typical Crown, QSC, or Hafler would probably
bury a Carver when it comes to difficult loads.

"would probably"... how would you know, Mr.
no-empirical-experiences?

Given the rather conspicious reliable evidence
that I've got considerable emperical experience
with these and many other amps, one is tempted to ask
what the heck are you ranting about, Powell?

Rubbish. Talking about amps is not experience.
We all know you’ve not subscribed to any audio
magazines in the last 20 years... so you’re not
even well read on the subject.


Krell, Levinson and others
could be said to "bury" your biased picks, too.

True, there's no theoretical limit to how much an
amp can be underrated.

How would you know?


I'm currently using one rated at 175watts rms X 2 at 4 ohms.

Consider the fact that your typical Crown, QSC or Hafler has
4-ohm bridged ratings. That correspond to a 2 ohm load.

Why is that relevant (bridging) to the poster's
application/needs?

See former comments about "difficult loads" and
comment just above about "2 ohm load".

So what? The poster has not described his speakers
and has not complained about the ability to drive them.
You need a bigger shovel, Arny.


RMS load rating is not
the major determinant in high fidelity reproduction.

So Powell, does that mean that your main system
with speakers has power amps rated at 100
milliwatts, RMS? Of course not. There's at least a
loose relationship between RMS power ratings and
ability to drive speakers to useful volume levels.

You're the only thing "loose" and half cocked.

In fact there's no other spec that is vastly different,
and more relevant.

Relevant as a "loose relationship", according to you.


It is only one factor of many to consider.

Name a commonly-used amplifier spec that is vastly
different and also a better predictor of an amps ability
to drive speakers to satisfying levels.

Top Ten of important factors to consider:
1. The ability to satisfy the user's sound preferences.
2. The compatibility of the pre-amp to drive the power
amp.
3. The fidelity of the amp to discern fine detail, sound
stage and microdynamics.
4. Physical size limitations and cooling requirements
for placement in the user's setup.
5. Manufacturer's warranty and reliability.
6. Budget.
7. Quality and fit-and-finish.
8. Will it meet the needs for future expansion, if any?
9. Will the sound fidelity vary depending on
loudness?
10. Special requirements such as input like XLR,
vacuum tube vs SS, number of channels needed,
etc.

I love the look of the Carvers with the two analog power
meters on the front.

I'd trade a really sensitive, accurate clipping light
for fancy meters in a heart beat.

Quack, quack, quack...

So Powell, does that mean that given the chance, you
took the fancy meters that impress visiting-firemen
and small children?

The meters on the TFM line are very good,
mr. meter reader .

In article , "Rusty Boudreaux" wrote:
"Robert Morein" wrote in message
...
MOSFET amps are the most durable of all solid state amplifiers.
They can
drive any load without output damage, and if you're reasonably
lucky, they
will survive a dead short. The MOSFET transistor is now
ubiquitous in power
switching applications because of it's ruggedness.

Really? That's an exceptional claim. Why do you claim MOSFETs
amps are any more durable than a bipolar output stage amp?

Except for switching amps, car audio uses almost exclusively bipolar
output designs, down to below 2 ohms. Seems like ruggedness
in solid state amps is advertising propaganda, but few new
solid state amps have MOSFET outputs.

greg

"Arny Krueger" wrote in message
...
The reason MOSFET output stages are ubiquitous these days is
cost
and availability.

Actually, it's BJT output stages that are ubiquitous but you've
got the
reasons right - cost and availability.

Obviously, you're correct. I meant BJT but had MOSFET on the
brain. My bad.

"Powell" wrote in message
...
Given the rather conspicious reliable evidence
that I've got considerable emperical experience
with these and many other amps, one is tempted to ask
what the heck are you ranting about, Powell?

Rubbish. Talking about amps is not experience.
We all know you've not subscribed to any audio
magazines in the last 20 years... so you're not
even well read on the subject.

Thanks for the best laugh I've had all day for suggesting that
magazines will keep you "well read".

Although I subscribe to several print magazines they are really
worthless. By the time a review is published the product is
usually darn near obsolete. I can't remember how many years it's
been since I read something first in an audio mag. Q&A is
instead usually Q & wrongA. Feature articles usually miss the
mark even if they aren't scientifically flawed. I've kept all my
mag subscriptions through the years except Stereophile which I
failed to renew a few months ago. My colleagues and I took great
enjoyment from the gut busting laughs Stereophile offers every
month. For awhile, we made Top Ten lists for each issue and put
them in the humor email list. In the end it just got boring
laughing at the same stuff issue after issue no matter how
outrageous.

I'd like to see a poll of how many true audio professionals get
trade rags. Even including free subscriptions I bet the numbers
are quite low.

"gregs" wrote in message
. ..
In article , "Rusty Boudreaux"
wrote:
"Robert Morein" wrote in message
...
MOSFET amps are the most durable of all solid state amplifiers.
They can
drive any load without output damage, and if you're reasonably
lucky, they
will survive a dead short. The MOSFET transistor is now
ubiquitous in power
switching applications because of it's ruggedness.

Really? That's an exceptional claim. Why do you claim MOSFETs
amps are any more durable than a bipolar output stage amp?

Except for switching amps, car audio uses almost exclusively bipolar
output designs, down to below 2 ohms. Seems like ruggedness
in solid state amps is advertising propaganda, but few new
solid state amps have MOSFET outputs.

greg

Permit me to clarify my comment. When I said MOSFETs are ubiquitous in power
switching applications, I was not referring to audio. Power converters,
inverters, motor drivers, and all other industrial applications for power
control use MOSFETs, except for some rare IGBT apps.

Bipolar is the dominant technology for audio amplification. However, thermal
runaway has never been solved. It cannot be protected against by feedback or
any linear network. Practical protective circuits exist, but they DO fail
when pushed to the limit. By contrast, a MOSFET circuit is simply immune to
thermal runaway, because the physical process does not exist in the
semiconductor. It is for this reason that it has been universally adopted
for the above mentioned industrial apps.

"Arny Krueger" wrote in message
...
"Robert Morein" wrote in message

"Arny Krueger" wrote in message
...
"Robert Morein" wrote in message


The QSC is muddy. It's performance is a throwback to the bipolar
amplifiers of the late 70's and early 80's.

Thus says a guy who would apparently die ignorant and inexperienced
rather than do a level-matched, time-synched bias-controlled
listening test.

Thusw says an engineer who has questionable hearing.

Tell us why your hearing is unimpeachible, Morein.

You have a nasty habit of replying to nonexistent statements.
The fact that I can't stand the QSC, while you appear to love it, indicates
to me that there is some element of your discriminatory ability that is
simply missing. I do not know whether this is due to physical impairment or
neural processing.

The QSC is a piece of junk. It's a watt-pumper, and I advise anyone who
thinks he has taste to give it a wide berth.

Tell us why you shower with a firehose.

On Wed, 31 Dec 2003 12:10:51 -0500, "Robert Morein"
wrote:

The sound of the traditional MOSFET circuit has both followers and
detractors, to which I add my personal observation that they complement
metal dome tweeters very well, but are not as good with fabric types.

Absolute bolllocks! As with bipolars and even a select few tube amps,
a good amp sounds like a good amp, i.e. it sounds like its input
signal. They all sound the same, hence they don't 'complement' any
particular kind of tweeter.

Further, there's even more ******** in your sweeping generalisation
that metal dome and soft dome tweeters have a characteristic sound.
They don't.
--

Stewart Pinkerton | Music is Art - Audio is Engineering

"Powell" wrote in message

"Arny Krueger" wrote

"Arny Krueger" wrote

Since the consensus here seems to
indicate going with the more pricey Crown or Hafler
amplifiers, I think I will revert my focus back to
obtaining a higher powerered Carver amplifier.

Your typical Crown, QSC, or Hafler would probably
bury a Carver when it comes to difficult loads.

"would probably"... how would you know, Mr.
no-empirical-experiences?

Given the rather conspicuous reliable evidence
that I've got considerable empirical experience
with these and many other amps, one is tempted to ask
what the heck are you ranting about, Powell?

Rubbish. Talking about amps is not experience.

Agreed. Listening to them and measuring is. Been there, done that when it
comes to amps made by Crown, QSC, Hafler, Bryston, Parasound, Dyna, Alesis,
Yamaha, etc.

We all know you've not subscribed to any audio
magazines in the last 20 years... so you're not
even well read on the subject.

Rubbish. Reading about amps is not experience.

Krell, Levinson and others
could be said to "bury" your biased picks, too.

True, there's no theoretical limit to how much an
amp can be underrated.

How would you know?

Been there, done that.

I'm currently using one rated at 175watts rms X 2 at 4 ohms.

Consider the fact that your typical Crown, QSC or Hafler has
4-ohm bridged ratings. That correspond to a 2 ohm load.

Why is that relevant (bridging) to the poster's
application/needs?

See former comments about "difficult loads" and
comment just above about "2 ohm load".

So what? The poster has not described his speakers
and has not complained about the ability to drive them.

As you said Powell, so what. He may or may not have the problem, he may or
may not know that he will have the problem, but its a situation that he may
want to consider. I'm just providing evidence that he can use to base his
choice on.

You need a bigger shovel, Arny.

Been there, done that.

RMS load rating is not
the major determinant in high fidelity reproduction.

So Powell, does that mean that your main system
with speakers has power amps rated at 100
milliwatts, RMS? Of course not. There's at least a
loose relationship between RMS power ratings and
ability to drive speakers to useful volume levels.

You're the only thing "loose" and half cocked.

Personal attacks won't help your case, Powell. They just make you look
"loose" and "half cocked".

In fact there's no other spec that is vastly different,
and more relevant.

Relevant as a "loose relationship", according to you.

No problem.

It is only one factor of many to consider.

Name a commonly-used amplifier spec that is vastly
different and also a better predictor of an amps ability
to drive speakers to satisfying levels.

Top Ten of important factors to consider:

1. The ability to satisfy the user's sound preferences.

Not a spec, therefore irrelevant to the question I asked.

2. The compatibility of the pre-amp to drive the power
amp.

Not a spec, therefore irrelevant to the question I asked.

3. The fidelity of the amp to discern fine detail, sound
stage and microdynamics.

Not a spec, therefore irrelevant to the question I asked.

4. Physical size limitations and cooling requirements
for placement in the user's setup.

Irrelevant as a predictor of an amps ability to drive speakers to
satisfying levels and therefore irrelevant to the question I asked.

5. Manufacturer's warranty and reliability.

Irrelevant as a predictor of an amps ability to drive speakers to
satisfying levels and therefore irrelevant to the question I asked.

6. Budget.

Irrelevant as a predictor of an amps ability to drive speakers to
satisfying levels and therefore irrelevant to the question I asked.

7. Quality and fit-and-finish.

Irrelevant as a predictor of an amps ability to drive speakers to
satisfying levels and therefore irrelevant to the question I asked.

8. Will it meet the needs for future expansion, if any?

Not a spec, therefore irrelevant to the question I asked.

9. Will the sound fidelity vary depending on
loudness?

Not a spec, therefore irrelevant to the question I asked.

10. Special requirements such as input like XLR,
vacuum tube vs SS, number of channels needed,
etc.

Too obvious.

I love the look of the Carvers with the two analog power
meters on the front.

I'd trade a really sensitive, accurate clipping light
for fancy meters in a heart beat.

Quack, quack, quack...

So Powell, does that mean that given the chance, you
took the fancy meters that impress visiting-firemen
and small children?

The meters on the TFM line are very good, mr. meter reader .

Good for what, impressing visiting-firemen and small children?

Powell, thanks for again showing once again that you can't respond properly
to even the simplest of questions.

"Robert Morein" wrote in message

"Arny Krueger" wrote in message
...
"Robert Morein" wrote in message

"Arny Krueger" wrote in message
...
"Robert Morein" wrote in message


The QSC is muddy. It's performance is a throwback to the bipolar
amplifiers of the late 70's and early 80's.

Thus says a guy who would apparently die ignorant and inexperienced
rather than do a level-matched, time-synched bias-controlled
listening test.

Thusw says an engineer who has questionable hearing.

Tell us why your hearing is unimpeachable, Morein.

You have a nasty habit of replying to nonexistent statements.

Your inability to see simple logic is quite revealing, Morein. You complain
that my hearing is questionable, but you apparently can't even understand
the need to consider whether your hearing is any less questionable.

You're belaboring the obvious - of course my hearing is questionable, and so
is yours and that of everybody else on the group.

The fact that I can't stand the QSC, while you appear to love it,
indicates to me that there is some element of your discriminatory
ability that is simply missing.

Yes, I'm arguably less biased and prejudiced based on intangibles, then you
are.

I do not know whether this is due to
physical impairment or neural processing.

OK, which means that your hearing is just as questionable as mine. Therefore
your attack on me based on the questionable nature of my hearing indicts you
as well. In short, it is a self-defeating thing for you to do.

The QSC is a piece of junk.

OSAF.

It's a watt-pumper, and I advise anyone who thinks he has taste to give
it a wide berth.

Please give whatever unqualified advice you wish to, Morein. It's a free
country and you can make yourself look as silly as you would like to.

Tell us why you shower with a firehose.

Inefficient speakers - less than 85 dB/watt. Relatively large room. Desire
for realistic sound levels.

"Robert Morein" wrote in message


Permit me to clarify my comment. When I said MOSFETs are ubiquitous
in power switching applications, I was not referring to audio. Power
converters, inverters, motor drivers, and all other industrial
applications for power control use MOSFETs, except for some rare IGBT
apps.

This has a much to do with the need for high speed at ultrasonic
frequencies, as anything else. Probably more so.

Bipolar is the dominant technology for audio amplification. However,
thermal runaway has never been solved. It cannot be protected against
by feedback or any linear network.

The predominant means for protecting BJTs against thermal runaway is exactly
feedback, feedback of a nonlinear nature.

Practical protective circuits
exist, but they DO fail when pushed to the limit.

Nonsense.

By contrast, a
MOSFET circuit is simply immune to thermal runaway, because the
physical process does not exist in the semiconductor. It is for this
reason that it has been universally adopted for the above mentioned
industrial apps.

That's not right, either. There are tons of BJTs in industrial power
switching apps.

"Rusty Boudreaux" wrote in message

"Powell" wrote in message
...

Given the rather conspicuous reliable evidence
that I've got considerable empirical experience
with these and many other amps, one is tempted to ask
what the heck are you ranting about, Powell?

Rubbish. Talking about amps is not experience.
We all know you've not subscribed to any audio
magazines in the last 20 years... so you're not
even well read on the subject.

Thanks for the best laugh I've had all day for suggesting that
magazines will keep you "well read".

I like the juxtapositioning of a true statement:

"Talking about amps is not experience."

With his apparent claim that reading about amps would somehow mitigate this
problem.

Reading between the lines Powell is very proud that he reads about
amplifiers, LOTS!

What Powell is missing is the obvious connection between the data on my web
sites and intimate and continuing contact with the amplifiers that it is
attributed to. Amps tend to have technical and in some sense audible
signatures. It can be possible to falsify a claim that detailed technical
data came from a certain amplifier. I wouldn't risk that.

Although I subscribe to several print magazines they are really
worthless.

Case in point TAS, which I was a charter subscriber to in my more gullible
days.

By the time a review is published the product is
usually darn near obsolete. I can't remember how many years it's
been since I read something first in an audio mag.

Ever since you started surfing the web?

Q&A is
instead usually Q & wrongA. Feature articles usually miss the
mark even if they aren't scientifically flawed. I've kept all my
mag subscriptions through the years except Stereophile which I
failed to renew a few months ago.

That's how it happened with me.

My colleagues and I took great
enjoyment from the gut busting laughs Stereophile offers every
month.

Indeed.

For awhile, we made Top Ten lists for each issue and put
them in the humor email list. In the end it just got boring
laughing at the same stuff issue after issue no matter how
outrageous.

Agreed.

I'd like to see a poll of how many true audio professionals get
trade rags. Even including free subscriptions I bet the numbers
are quite low.

I think that there is plenty of evidence that Stereophile's magazine sales
are shrinking at a rate that should and probably does greatly concern
Atkinson. I've heard that Atkinson admits it privately. He might even admit
it publicly. Ironically, I don't think his inadequacies as an editor and
reviewer are the sole cause. Demographics are against him.

The best market information I have suggests that 2-channel audio is dying
pretty rapidly, HT is still rising strongly and probably will continue to
rise as it is closely tied to the switchover to HDTV, that aftermarket car
audio is stagnant but strong, that audio without available video will
languish and eventually die out; and that extreme portable audio is back as
the hottest new thing after languishing for years due to the commoditization
of the Walkman.

"Stewart Pinkerton" wrote in message

On Wed, 31 Dec 2003 12:10:51 -0500, "Robert Morein"
wrote:

The sound of the traditional MOSFET circuit has both followers and
detractors, to which I add my personal observation that they
complement metal dome tweeters very well, but are not as good with
fabric types.

Absolute bolllocks! As with bipolars and even a select few tube amps,
a good amp sounds like a good amp, i.e. it sounds like its input
signal. They all sound the same, hence they don't 'complement' any
particular kind of tweeter.

Agreed. The ideal amp is a "straight wire with gain", and many amplifiers
approximate this quite well, particularly if only reliable subjective means
are used to judge.

Further, there's even more ******** in your sweeping generalization
that metal dome and soft dome tweeters have a characteristic sound.
They don't.

Agreed. While intuition might suggest that metal domes might have stronger
high frequency response, the most popular dome-type tweeters with the most
extended response (40 KHz & beyond) have fabric diaphragms.

"Robert Morein" wrote in message
...
Permit me to clarify my comment. When I said MOSFETs are
ubiquitous in power
switching applications, I was not referring to audio. Power
converters,
inverters, motor drivers, and all other industrial applications
for power
control use MOSFETs, except for some rare IGBT apps.

Generally true but "rare apps" is a too wide sweeping of a
statement.

Power MOSFETs make up the bulk of the mainstream switchmode power
conversion. However, very large inverters, motor drives and
other apps routinely use other devices such as bipolars and
combination devices (MCTs and IGBTs to name a few). Many
actually use a BOTH device types such as MCTs or IGBTs for the
main power devices and MOSFETs either in parallel to reduce
switching loss or to force resonant switching. On the low power
side many switching regulator ICs (both offline and low voltage
DC-DC) use onboard bipolar transistors due to ease of integration
with control functions (although newer devices such as STs VIPer
uses onboard HV MOSFET) . I believe the vast majority of low end
TV sets still use bipolars for the high voltage flyback.
Electronic ballasts for florescent lighting are using more and
more MOSFETs but the majority still use bipolars in a self driven
architecture due to cost. Just about any application where
breakdown voltage exceeds 1200V is exclusively bipolar. Ditto
for high voltage and high current applications. You can get an
IGBT rated for 3,300V and 1,200A with 500ns switching in a small
module which just can't be done with current generation MOSFETs.

In many cases it boils down to cost. Bipolar structures use far
less silicon for the same current density. MOSFETs usually make
the most sense when either cost isn't the primary concern, fast
switching speed is required (without resonant techniques), or the
MOSFET die size can be large enough to have a lower conduction
losses than bipolar. In the commercial world MOSFETs usually
meet this critera when the power is more than a few watts but
less than a few kW.

Bipolar is the dominant technology for audio amplification.
However, thermal
runaway has never been solved. It cannot be protected against
by feedback or
any linear network.

Wrong. Many bulletproof protection methods are available and
have been for decades. Just because audio designers can be
ignorant and continually try to reinvent the wheel doesn't mean
the rest of the world hasn't figured out how to do it right.

I've designed kilowatt output switching power supplies with
bipolar devices which can withstand any overload you can throw at
it...even at a steady state operating temperature of 150C.

when pushed to the limit. By contrast, a MOSFET circuit is
simply immune to
thermal runaway, because the physical process does not exist in
the
semiconductor.

Simply immune is simply wrong.

Thermal runaway most certainly exists in a MOSFET. ON resistance
is a strong function of temperature. The hotter the MOSFET the
higher the ON resistance. Higher ON resistance causes more power
dissipation which causes temperature to rise which increases ON
resistance which causes temperature to rise which....BOOM!

In the case of a switching power supply you can easily get the
MOSFET in a state where it thermally runs away. I've had
prototypes where the MOSFET is running fine at a given ambient
temperature. Increase the ambient temperature by only 5C and the
MOSFET quickly runs away and exceeds the 175C rating and dies.

You may be confusing the situation where you have devices in
parallel. If an individual FET heats up the increased ON
resistance forces current to the other FETs which gives nice
current sharing. Bipolars in parallel don't share well by
themselves since as one heats up it's Vce decreases which allows
more current to flow in that device and can cause runaway.

It is for this reason that it has been universally adopted
for the above mentioned industrial apps.

Careful with the use of 'industrial'. Industrial usually means
high power and/or high voltage in which bipolar reins supreme
(steel mills, production facilities, etc). It is the commercial
world in which MOSFETs are most common (PC power
supplies/motherboards etc).

"Robert Morein" wrote in message
...
The QSC is a piece of junk. It's a watt-pumper, and I advise
anyone who
thinks he has taste to give it a wide berth.

Please elaborate on why YOU think this is the case. It's
certainly not the opinion of the rest of the audio world.

bsguidry wrote:

[arny said]

Good brands to look at include QSC, Hafler, and Crown. If you
surf the vendor web sites, you'll find very detailed RMS power
specs.

[morein said]

Take QSC off the list. It's a testament to Arny's hearing
difficulties. Othewise, I concur.

I've definitely consider QSC and Crown, however, I've not
encountered Hafler very often in my searching.

I haven't heard any "recent un's" of the amps mentioned, but based on
the context I have seen them mentioned in I would go for QSC for the
bass and Hafler for "the above rest", and skip Crown as being not cost
efficient in the context.

Other brands that caught my
attention were Nady, Samson, Peavey, and Behringer.

Behringer tends to be getting ever more an interesting dark horse
specwise and from what people who suggest them.

The fan noise could be a problem as suggested. Since
the concensus here seems to indicate going with the more
pricey Crown or Hafler amplifiers, I think I will revert
my focus back to obtaining a higher powerered
Carver amplifier.

There must be real bargains out there amongst the "crap bipolars from
the 70-ties and 80-ties", but perhaps not in the power class you want,
mostly it is the below 150 watts from that time and age you find the
good ones in. I recently bought a "stone age" Technics SE9021, and it
was a very positive surprise. Obvious caveats exist with so old stuff,
especially if it has not been recently or reasonably constantly used.

I'm currently using one rated at 175watts rms X 2
at 4 ohms. I love the look of the Carvers with the two analog power
meters on the front. I guess I'll keep scanning Ebay for good finds
on these. Thanks for all the feedback to this post and two my
previous posts about my Adire Tempest project.

bguidry

--
************************************************** *************
* \\\\\\\ Quality Ascii handcrafted by Peter Larsen /////// *
* \\\\\\\ My site is at: http://www.muyiovatki.dk /////// *
************************************************** *******

"Arny Krueger" wrote in message
...
"Rusty Boudreaux" wrote in message

"Powell" wrote in message
...

Given the rather conspicuous reliable evidence
that I've got considerable empirical experience
with these and many other amps, one is tempted to ask
what the heck are you ranting about, Powell?

Rubbish. Talking about amps is not experience.
We all know you've not subscribed to any audio
magazines in the last 20 years... so you're not
even well read on the subject.

Thanks for the best laugh I've had all day for suggesting
that
magazines will keep you "well read".

I like the juxtapositioning of a true statement:

"Talking about amps is not experience."

With his apparent claim that reading about amps would somehow
mitigate this
problem.

Reading between the lines Powell is very proud that he reads
about
amplifiers, LOTS!

My wife reads murder-mysteries. I'm surprised the FBI hasn't
called for her help yet.

What Powell is missing is the obvious connection between the
data on my web
sites and intimate and continuing contact with the amplifiers
that it is
attributed to. Amps tend to have technical and in some sense
audible
signatures. It can be possible to falsify a claim that detailed
technical
data came from a certain amplifier. I wouldn't risk that.

Agreed.

By the time a review is published the product is
usually darn near obsolete. I can't remember how many years
it's
been since I read something first in an audio mag.

Ever since you started surfing the web?

Yeah, pretty much.

I think that there is plenty of evidence that Stereophile's
magazine sales
are shrinking at a rate that should and probably does greatly
concern
Atkinson. I've heard that Atkinson admits it privately. He
might even admit
it publicly. Ironically, I don't think his inadequacies as an
editor and
reviewer are the sole cause. Demographics are against him.

I had noticed the drop on their gov't filing page for
circulation.

Is Stereophile Guide to HT also edited by John? How's it doing?

The best market information I have suggests that 2-channel
audio is dying
pretty rapidly, HT is still rising strongly and probably will
continue to
rise as it is closely tied to the switchover to HDTV, that
aftermarket car
audio is stagnant but strong, that audio without available
video will
languish and eventually die out

That's certainly been my feeling. Why buy a CD partially filled
with poor music when a DVD is cheaper and has more and better
content?

The 2-channel world needs to drop the unnecessary high bit/high
frequency space hog and at least convert to multichannel
16bit/44kHz. Video is definitely a plus.

"Rusty Boudreaux" wrote in message
...
"Robert Morein" wrote in message
...
The QSC is a piece of junk. It's a watt-pumper, and I advise
anyone who
thinks he has taste to give it a wide berth.

Please elaborate on why YOU think this is the case. It's
certainly not the opinion of the rest of the audio world.


Based upon your use of "YOU" above, I will carefully label my response:

PERSONAL OPINION:
The QSC is a piece of junk.

WHY:
Amplifier had many of the sonic attributes of older, cold running bipolar
units.

CONJECTU
The QSC runs low bias current; therefore it uses precision biasing to
eliminate crossover distortion. Some schemes are more successful than
others. I do not believe the QSC to be the best in this category. As a
group, I find such amplifiers to be be less than the best.

REASON FOR VARIANCE OF OPINION
We're all sensitive to different things. The QSC is a great bass amp, and
capable of high volume levels. Fortunately, I have amplifiers that can do
these things, and sound good TO ME as well.

"Stewart Pinkerton" wrote in message
...
On Wed, 31 Dec 2003 12:10:51 -0500, "Robert Morein"
wrote:

The sound of the traditional MOSFET circuit has both followers and
detractors, to which I add my personal observation that they complement
metal dome tweeters very well, but are not as good with fabric types.

Absolute bolllocks! As with bipolars and even a select few tube amps,
a good amp sounds like a good amp, i.e. it sounds like its input
signal. They all sound the same, hence they don't 'complement' any
particular kind of tweeter.

No they don't all sound the same. Otherwise, you could get rid of your
KSA-50 and get a good Japanese receiver.

Further, there's even more ******** in your sweeping generalisation
that metal dome and soft dome tweeters have a characteristic sound.
They don't.

It depends upon whether you go by averages, or the "exception that breaks
the rule."
There certainly are exceptions.
--

Stewart Pinkerton | Music is Art - Audio is Engineering

"Rusty Boudreaux" wrote in message

"Arny Krueger" wrote in message
...
"Rusty Boudreaux" wrote in message


I think that there is plenty of evidence that Stereophile's magazine
sales are shrinking at a rate that should and probably does greatly
concern Atkinson. I've heard that Atkinson admits it privately. He
might even admit it publicly. Ironically, I don't think his
inadequacies as an editor and reviewer are the sole cause.
Demographics are against him.

I had noticed the drop on their gov't filing page for
circulation.

Is Stereophile Guide to HT also edited by John?

I see evidence that its editor is Thomas Norton.

How's it doing?

You're asking the wrong guy. I don't read it.

The best market information I have suggests that 2-channel audio is
dying pretty rapidly, HT is still rising strongly and probably will
continue to rise as it is closely tied to the switchover to HDTV,
that aftermarket car audio is stagnant but strong, that audio
without available video will languish and eventually die out

That's certainly been my feeling. Why buy a CD partially filled
with poor music when a DVD is cheaper and has more and better
content?

Stated differently - if one is going to sit down and listen, why just listen
when you can also watch something that is relevant to the music?

The 2-channel world needs to drop the unnecessary high bit/high
frequency space hog and at least convert to multichannel
16bit/44kHz.

I'm not a big fan of AC-3 - I'd rather listen to multichannel that hasn't
been perceptually compressed. For example, my portable hard drive player is
loaded with 100% .WAV files even though it cuts its capacity by over 10:1
and cuts battery life by about two due to the extra hard drive activity.

Video is definitely a plus.

"Arny Krueger" wrote in message
...
"Stewart Pinkerton" wrote in message

On Wed, 31 Dec 2003 12:10:51 -0500, "Robert Morein"
wrote:

The sound of the traditional MOSFET circuit has both followers and
detractors, to which I add my personal observation that they
complement metal dome tweeters very well, but are not as good with
fabric types.

Absolute bolllocks! As with bipolars and even a select few tube amps,
a good amp sounds like a good amp, i.e. it sounds like its input
signal. They all sound the same, hence they don't 'complement' any
particular kind of tweeter.

Agreed. The ideal amp is a "straight wire with gain", and many amplifiers
approximate this quite well, particularly if only reliable subjective
means
are used to judge.

Of course. Simply ignore the "in your face evidence" and keep looking at the
"data."


Further, there's even more ******** in your sweeping generalization
that metal dome and soft dome tweeters have a characteristic sound.
They don't.

Agreed. While intuition might suggest that metal domes might have stronger
high frequency response, the most popular dome-type tweeters with the most
extended response (40 KHz & beyond) have fabric diaphragms.

I have a set of Polks with the new Audax ring drivers, and they STILL sound
soft, compared to a typical metal dome.

I can't ignore what I hear.

"Robert Morein" wrote in message


"Arny Krueger" wrote in message
...

Agreed. While intuition might suggest that metal domes might have
stronger high frequency response, the most popular dome-type
tweeters with the most extended response (40 KHz & beyond) have
fabric diaphragms.

I have a set of Polks with the new Audax ring drivers, and they STILL
sound soft, compared to a typical metal dome.

I note Morein that you can't even cite the name of any speakers with metal
dome tweeters.

I have a pair of NHT 2.5i speakers with metal domes and a pair of speakers
based on the Audax ring drivers that I designed myself. They both sound
great, neither sounds soft or harsh. Something about quality of
implementation...

I can't ignore what I hear.

Neither can I.

On Thu, 1 Jan 2004 11:40:48 -0500, "Arny Krueger"
wrote:

That's certainly been my feeling. Why buy a CD partially filled
with poor music when a DVD is cheaper and has more and better
content?

Stated differently - if one is going to sit down and listen, why just listen
when you can also watch something that is relevant to the music?

There are several good reasons.

The main one is that music is highly based on the imagination of the
listener. You can actually minimize the impact of the music by tying
images chosen by someone else to the listening of said music.

This isn't to say that it can't be effective. But for instance, I
usually don't like watching videos of symphony orchestras performing
music. I simply find it distracting. Sometimes the editing is
distracting, sometimes it's just the camera angles. Others might
disagree of course.

Then there's the issue of artistic videos interpreting music.
Sometimes it works and sometimes it doesn't.

So, there are plenty of good reasons for forgoing watching video while
listening to music.

Yes, I'm arguably less biased and prejudiced based on intangibles, then you
are.

LOL

"dave weil" wrote in message

On Thu, 1 Jan 2004 11:40:48 -0500, "Arny Krueger"
wrote:

That's certainly been my feeling. Why buy a CD partially filled
with poor music when a DVD is cheaper and has more and better
content?

Stated differently - if one is going to sit down and listen, why
just listen when you can also watch something that is relevant to
the music?

There are several good reasons.

The main one is that music is highly based on the imagination of the
listener. You can actually minimize the impact of the music by tying
images chosen by someone else to the listening of said music.

Or, you can increase the impact of the music, or you can change it. You
don't have to watch if you don't want to. If you don't watch you have the
experience(s) you've described which I agree can have tremendous value, but
if you do watch, you have the benefit of a different experience.

This isn't to say that it can't be effective. But for instance, I
usually don't like watching videos of symphony orchestras performing
music. I simply find it distracting. Sometimes the editing is
distracting, sometimes it's just the camera angles. Others might
disagree of course.

I agree, but I like having the choice.

Then there's the issue of artistic videos interpreting music.
Sometimes it works and sometimes it doesn't.

I agree, but I like having the choice.

So, there are plenty of good reasons for forgoing watching video while
listening to music.

I agree, but I like having the choice.