[William Sommerwerck]

"Arny Krueger" wrote in message
. ..

I seriously doubt that in this day and age, Crown would field an amplifier
that simply failed to work or would unconditionally sound bad, if in good
working condition. I say this somewhat advisedly, having some inside
information about the reliability of some of their parent company's OEM
power amps for automotive use.

Which is why I bought some K1s without auditioning them.

As I've said before, Dr. Clayton Barclay, no longer with Crown, twice
apologized to me for Crown having manufactured them. He had left the
company, and was not present to block their manufacture.

If I recall correctly, he told me that the K1s had never been subjected to
Crown input-output null test, which reveals distortion with program
material, not test tones.

Dr. Barclay urged me to find Crown "Power Line" amps, which were his
favorites, and (of course) are no longer made. He said they could achieve a
90dB I/O null on program material.

[David Gravereaux]

Scott Dorsey wrote:
David Gravereaux wrote:
Scott Dorsey wrote:
...
I have never heard a switching amplifier which didn't sound bad.
Ditto. Although I would love to use this MOSFET class A/B design I have
in a product, which sounds amazingly good, I can't due to thermal
requirements. I've tried numerous high efficiency modules made by
IcePower and PowerOne, and I've come the same conclusion. They all
sound like crap. Mostly an unnatural crispyness to the top-end and lack
of punch in the bottom.

Look at the Tripath modules. They seem to be the best of the set. Also
look at a more aggressive integration stage... don't worry if your top end
response sags a bit on paper... it will sound better.
--scott

Thanks Scott. Their website seems to be off-the-air, but found a
datasheet on the 2022 and it looks nice, but it needs a bi-polar supply
input. I need single-ended. I already have enough buck converters
splitting out the main +48V feed into +/-12V,+5V, and +24V to the other
electronics. I hear you on the integration aspect. This speaker is
well processed using a DSP engine for x-over, filtering, limiting, etc,
so acual response on paper of the amps doesn't have much merit to the
result.

For those that noticed, PowerOne makes switch-mode power supplies, not
amps. I meant to say PowerPhysics.

[Arny Krueger]

"David Gravereaux" wrote in message

Scott Dorsey wrote:
David Gravereaux wrote:
Scott Dorsey wrote:
...
I have never heard a switching amplifier which didn't
sound bad.
Ditto. Although I would love to use this MOSFET class
A/B design I have in a product, which sounds amazingly
good, I can't due to thermal requirements. I've tried
numerous high efficiency modules made by IcePower and
PowerOne, and I've come the same conclusion. They all
sound like crap. Mostly an unnatural crispyness to the
top-end and lack of punch in the bottom.

Look at the Tripath modules. They seem to be the best
of the set. Also look at a more aggressive integration
stage... don't worry if your top end response sags a bit
on paper... it will sound better. --scott

Thanks Scott. Their website seems to be off-the-air,

Word has it that they may be in financial trouble.

but
found a datasheet on the 2022 and it looks nice, but it
needs a bi-polar supply input. I need single-ended. I
already have enough buck converters splitting out the
main +48V feed into +/-12V,+5V, and +24V to the other
electronics. I hear you on the integration aspect. This
speaker is well processed using a DSP engine for x-over,
filtering, limiting, etc, so acual response on paper of
the amps doesn't have much merit to the result.

For those that noticed, PowerOne makes switch-mode power
supplies, not amps. I meant to say PowerPhysics.

I have some experience with Tripath modules, and in my tests they did not
perform well. One problem is that they start spewing out a lot of ultrasonic
and high frequency sonic garbage a couple of dBs or more below clipping.

Also, Tripath modules have the typical switchmode amplfiier problem of
rising source impedance due to the output filter network. The impedance
curve of your speaker's tweeters can change how they sound. If your
application is the closed system it appears to be, then this won't be much
of a problem as long as you see it coming.

If you check around you will find a lot of critical statements about Tripath
modules. There are some european designs that get better press.

[Scott Dorsey]

Arny Krueger wrote:
"David Gravereaux" wrote in message
but
found a datasheet on the 2022 and it looks nice, but it
needs a bi-polar supply input. I need single-ended. I
already have enough buck converters splitting out the
main +48V feed into +/-12V,+5V, and +24V to the other
electronics. I hear you on the integration aspect. This
speaker is well processed using a DSP engine for x-over,
filtering, limiting, etc, so acual response on paper of
the amps doesn't have much merit to the result.

I think their power consumption is sufficiently symmetric that you
might be able to make them operate with a +48V rail using a small
+24V current as a reference ground. Of course you will have to AC
couple everything.

For those that noticed, PowerOne makes switch-mode power
supplies, not amps. I meant to say PowerPhysics.

I have some experience with Tripath modules, and in my tests they did not
perform well. One problem is that they start spewing out a lot of ultrasonic
and high frequency sonic garbage a couple of dBs or more below clipping.

This is "soft clipping" right? Everybody likes that. Well, actually I
would characterize it as a lowered clipping point.

Also, Tripath modules have the typical switchmode amplfiier problem of
rising source impedance due to the output filter network. The impedance
curve of your speaker's tweeters can change how they sound. If your
application is the closed system it appears to be, then this won't be much
of a problem as long as you see it coming.

This is an issue with all of the class D systems in one form or another, I
am sorry to report.

If you check around you will find a lot of critical statements about Tripath
modules. There are some european designs that get better press.

There is a division of B&O which is making some which have got very good
press, actually. I was not impressed with their demo at the AES, which
was very glassy-sounding, though that could have been a speaker issue in part.
Still, if the staff don't have the ability and the listening skills to make
a demo sound good, that's not a good sign that they can make the part sound
good either. Also, Hegel AS of Norway has been selling some that have a good
reputation. I have only heard those used with subwoofers, though.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."

[Arny Krueger]

"Scott Dorsey" wrote in message

Arny Krueger wrote:
"David Gravereaux" wrote in message
but
found a datasheet on the 2022 and it looks nice, but it
needs a bi-polar supply input. I need single-ended. I
already have enough buck converters splitting out the
main +48V feed into +/-12V,+5V, and +24V to the other
electronics. I hear you on the integration aspect.
This speaker is well processed using a DSP engine for
x-over, filtering, limiting, etc, so acual response on
paper of the amps doesn't have much merit to the result.

I think their power consumption is sufficiently symmetric
that you
might be able to make them operate with a +48V rail using
a small +24V current as a reference ground. Of course
you will have to AC
couple everything.

For those that noticed, PowerOne makes switch-mode power
supplies, not amps. I meant to say PowerPhysics.

I have some experience with Tripath modules, and in my
tests they did not perform well. One problem is that
they start spewing out a lot of ultrasonic and high
frequency sonic garbage a couple of dBs or more below
clipping.

This is "soft clipping" right?

No, the high frequency garbage is not harmonics of the signal being
amplified.


Also, Tripath modules have the typical switchmode
amplfiier problem of rising source impedance due to the
output filter network. The impedance curve of your
speaker's tweeters can change how they sound. If your
application is the closed system it appears to be, then
this won't be much of a problem as long as you see it
coming.

This is an issue with all of the class D systems in one
form or another, I am sorry to report.

Except those that have complex low pass filters at their output, or use some
kind of loop feedback.

If you check around you will find a lot of critical
statements about Tripath modules. There are some
european designs that get better press.

There is a division of B&O which is making some which
have got very good press, actually. I was not impressed
with their demo at the AES, which
was very glassy-sounding, though that could have been a
speaker issue in part.

I'm not aware of any listening tests of these products that I could call
definitive.

Still, if the staff don't have the
ability and the listening skills to make
a demo sound good, that's not a good sign that they can
make the part sound good either.

I don't put a lot of stock in convention demos, whether the outcomes are
good or bad.

Also, Hegel AS of
Norway has been selling some that have a good reputation.

http://www.hegel.no/index.htm ???

I don't see any references to switchmode power amps.

[David Gravereaux]

Scott Dorsey wrote:

There is a division of B&O which is making some which have got very good
press, actually.

Yes, that's IcePower. They measure better than they sound. To me,
there's nothing much better than a lateral MOSFET output class A/B power
amp; nevermind the heat. This drive for efficiency is costly for sound
quality.

To bad I can't dissipate 40W of heat to the stainless front grill.. lots
of surface area there. Mechanical constraints make it so I can't. If I
could, should be about a temp rise of 8 degrees C (math be damned,
that's an educated guess) which should OK to touch.