Pictures by: Tom Hole comparing Berhinger and QSC power amps:

http://www.tomhole.com/Behringer%20E...RMX%202450.htm

Not surprising at all. Mackie once sued Behringer for "cloning" at
least one model Mackie microphone mixer (possibly other models as
well). Looks like Behringer still hasn't learned their lesson.

Brian Aase

On Fri, 27 Aug 2004 17:05:37 -0400, "Arny Krueger"
wrote:

Pictures by: Tom Hole comparing Berhinger and QSC power amps:

http://www.tomhole.com/Behringer%20E...RMX%202450.htm



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"Brian A" wrote in message
...
Not surprising at all. Mackie once sued Behringer for "cloning" at
least one model Mackie microphone mixer (possibly other models as
well). Looks like Behringer still hasn't learned their lesson.

Since Mackie lost, what lesson would that be?

TonyP.

"François Yves Le Gal" wrote in message

On Sun, 29 Aug 2004 14:46:33 +1000, "TonyP"
wrote:

Since Mackie lost, what lesson would that be?

That "better sound thru litigation" has only worked with Bose?


"Better sound thru litigation" clearly did not work for Carver. The
defendent was the parent company of Velodyne. Having deep pockets they
mounted a spirited not to mention expensive defense which was so effective,
that Carver had to pay for it!

http://www.audioholics.com/news/pres...ferlawsuit.php

"Arny Krueger" wrote in message ...
Pictures by: Tom Hole comparing Berhinger and QSC power amps:

http://www.tomhole.com/Behringer%20E...RMX%202450.htm

While noting the similarities, I encourage looking at the differences
too. Tomorrow (when I have access to a fast network connection) I will
take a closer look at the pictures, but my first impression is that
the QSC has roughly twice as big a power transformer, and perhaps more
beefy components in general.

"François Yves Le Gal" wrote in message

On Sun, 29 Aug 2004 06:50:17 -0400, "Arny Krueger"
wrote:

"Better sound thru litigation" clearly did not work for Carver.

Bob Carver was quite stupid at trying to have an unforceable patent
enforced in court...

His stupidity was enhanced by his previous successes at bullying smaller
manufacturers into paying him royalties.

"Detector195" wrote in message
om

"Arny Krueger" wrote in message
...
Pictures by: Tom Hole comparing Berhinger and QSC power amps:

http://www.tomhole.com/Behringer%20E...RMX%202450.htm

While noting the similarities, I encourage looking at the differences
too. Tomorrow (when I have access to a fast network connection) I will
take a closer look at the pictures, but my first impression is that
the QSC has roughly twice as big a power transformer,


and perhaps more beefy components in general.

I notice lots more fasterners, and the use of sleeving on some line voltage
wiring.

(Detector195) wrote in message . com...
"Arny Krueger" wrote in message ...
Pictures by: Tom Hole comparing Berhinger and QSC power amps:

http://www.tomhole.com/Behringer%20E...RMX%202450.htm

While noting the similarities, I encourage looking at the differences
too. Tomorrow (when I have access to a fast network connection) I will
take a closer look at the pictures, but my first impression is that
the QSC has roughly twice as big a power transformer, and perhaps more
beefy components in general.

Oops, it was an optical illusion. Both amps have roughly the same size
transformers. The Behringer has more empty space, making it look like
it has a smaller transformer. Empty space is not necessarily a bad
thing, of course.

Now back to my quandary about power transformer sizing. These are
2-space amps, so they are no more than 3.5 inches thick, and the
transformers are about 5 inches in diameter. Quickly checking my
Digi-Key catalog, p. 1239, suggests that a toroidal transformer of
this size is rated at roughly 600 Watts, give or take. Of course this
is just for one brand (Amveco), but it seems unlikely to me that other
brands of toroids are going to be a significantly more efficient to
the point where it is believable that these are anything but 600 Watt
power transformers, in amplifiers rated at 2400 Watts.

The only conclusion I can come up with is that these power amps are
designed based on extremely optimistic assumptions about the types of
signals encountered in normal use. At best, one can hope that the amp
is designed so that the power transformer survives long enough for the
protection circuitry to shut everything down.

Being a regular subscriber to the music gear catalogs, I grow
increasingly skeptical about the stratospheric power ratings claimed
for amplifiers. Unless I am completely missing the boat on my
technical understanding.

This issue is growing in importance for me, as I approach the day of
reckoning when I have to shop for a more powerful bass amplifier.

Are they silly enough to run the transformers at 60HZ? With switching power
supplies they may be much higher and require less core material....
preferably well above 20khz....

Rgds:
Eric

"Detector195" wrote in message
om...
(Detector195) wrote in message
. com...
"Arny Krueger" wrote in message
...
Pictures by: Tom Hole comparing Berhinger and QSC power amps:

http://www.tomhole.com/Behringer%20E...RMX%202450.htm

While noting the similarities, I encourage looking at the differences
too. Tomorrow (when I have access to a fast network connection) I will
take a closer look at the pictures, but my first impression is that
the QSC has roughly twice as big a power transformer, and perhaps more
beefy components in general.

Oops, it was an optical illusion. Both amps have roughly the same size
transformers. The Behringer has more empty space, making it look like
it has a smaller transformer. Empty space is not necessarily a bad
thing, of course.

Now back to my quandary about power transformer sizing. These are
2-space amps, so they are no more than 3.5 inches thick, and the
transformers are about 5 inches in diameter. Quickly checking my
Digi-Key catalog, p. 1239, suggests that a toroidal transformer of
this size is rated at roughly 600 Watts, give or take. Of course this
is just for one brand (Amveco), but it seems unlikely to me that other
brands of toroids are going to be a significantly more efficient to
the point where it is believable that these are anything but 600 Watt
power transformers, in amplifiers rated at 2400 Watts.

The only conclusion I can come up with is that these power amps are
designed based on extremely optimistic assumptions about the types of
signals encountered in normal use. At best, one can hope that the amp
is designed so that the power transformer survives long enough for the
protection circuitry to shut everything down.

Being a regular subscriber to the music gear catalogs, I grow
increasingly skeptical about the stratospheric power ratings claimed
for amplifiers. Unless I am completely missing the boat on my
technical understanding.

This issue is growing in importance for me, as I approach the day of
reckoning when I have to shop for a more powerful bass amplifier.

"Detector195" wrote in message
om...
Now back to my quandary about power transformer sizing. These are
2-space amps, so they are no more than 3.5 inches thick, and the
transformers are about 5 inches in diameter. Quickly checking my
Digi-Key catalog, p. 1239, suggests that a toroidal transformer of
this size is rated at roughly 600 Watts, give or take. Of course this
is just for one brand (Amveco), but it seems unlikely to me that other
brands of toroids are going to be a significantly more efficient to
the point where it is believable that these are anything but 600 Watt
power transformers, in amplifiers rated at 2400 Watts.

The Behringer EP1500 uses a made in USA "Torroid" brand 800W transformer.
I doubt very much that the EP2500 uses a smaller one. However if you expect
to get 2400W RMS continuous from one of these amps, you will be
disappointed. Those who are more realistic will consider them good value.
In Australia you cannot buy the parts for the cost of the Behringer amps, I
doubt things are different in the USA.

My only complaint is the small amount of capacitance provided, but as you
note there is enough space to add more.

TonyP.

TonyP wrote:

The Behringer EP1500 uses a made in USA "Torroid" brand 800W transformer.

What makes you think that ?

The little red hedgehog sticker indicates the manufacturer is Toroid
International.

They have Asian factories in India, Sri Lanka and working on one in China too I
think.

They have no US facilities to the best of my knowledge.

See http://www.toroid.co.uk/ or http://www.toroid.se/english/

I doubt very much that the EP2500 uses a smaller one. However if you expect
to get 2400W RMS continuous from one of these amps, you will be
disappointed.

Says who ?

In the short term at least - transformers such as these can deliver much more
than their continuous VA rating would indicate.

Those who are more realistic will consider them good value.
In Australia you cannot buy the parts for the cost of the Behringer amps, I
doubt things are different in the USA.

Neither the QSC RMXs or the Behringers are made in the USA. They are made in
China.

My only complaint is the small amount of capacitance provided, but as you
note there is enough space to add more.

Those are 12,000 uF caps in the RMX2450. Not big enough ?


Graham

"Pooh Bear" wrote in message
...
TonyP wrote:

The Behringer EP1500 uses a made in USA "Torroid" brand 800W
transformer.
What makes you think that ?

The Behringer web site literature.

The little red hedgehog sticker indicates the manufacturer is Toroid
International.
They have Asian factories in India, Sri Lanka and working on one in China
too I
think.
They have no US facilities to the best of my knowledge.
See http://www.toroid.co.uk/ or http://www.toroid.se/english/

I'll take your word for it.

I doubt very much that the EP2500 uses a smaller one. However if you
expect
to get 2400W RMS continuous from one of these amps, you will be
disappointed.

Says who ?

In the short term at least - transformers such as these can deliver much
more
than their continuous VA rating would indicate.


That's why I said "RMS **CONTINUOUS**".
Having trouble reading?


Those who are more realistic will consider them good value.
In Australia you cannot buy the parts for the cost of the Behringer
amps, I
doubt things are different in the USA.

Neither the QSC RMXs or the Behringers are made in the USA. They are made
in
China.

Where did I say otherwise? Try reading what I write next time.

My only complaint is the small amount of capacitance provided, but as
you
note there is enough space to add more.

Those are 12,000 uF caps in the RMX2450. Not big enough ?

I was referring to the Behringer, but since you asked NO.

TonyP.

"TonyP" wrote in message
u...

"Brian A" wrote in message
...
Not surprising at all. Mackie once sued Behringer for "cloning" at
least one model Mackie microphone mixer (possibly other models as
well). Looks like Behringer still hasn't learned their lesson.

Since Mackie lost, what lesson would that be?

I was under the impression the offending mixer was withdrawn from sale in
the USA.....

geoff

"Eric K. Weber" wrote in message


Are they silly enough to run the transformers at 60HZ?

In this case, yes. This is still common with low-end power amps. QSC has
been a leader in the area of building amps with switchmode and stepped power
supplies, but those are all in higher-end amps.

With switching power supplies they may be much higher and require less
core material.... preferably well above 20khz....

The electronics to drive the transformers aren't exactly free. More and more
applications have been flipped into switchmode operation as times wear on,
and the driving electronics get cheaper. It's obviously only a matter of
time...

"TonyP" wrote in message
u
"Pooh Bear" wrote in message
...
TonyP wrote:


I doubt very much that the EP2500 uses a smaller one. However if
you expect to get 2400W RMS continuous from one of these amps, you
will be disappointed.

Says who ?

In the short term at least - transformers such as these can deliver
much more than their continuous VA rating would indicate.


That's why I said "RMS **CONTINUOUS**".
Having trouble reading?


There is *continuous* and there is **continuous**. Temperatures in bit power
transformers build up slowly - in minutes and hours. AFAIK, the longest term
standard test of power output is limited to 30 minutes. I've seen
transformers do 30 minutes no sweat, but fail due to thermal stress several
hours later.

TonyP wrote:

"Pooh Bear" wrote in message
...
TonyP wrote:

The Behringer EP1500 uses a made in USA "Torroid" brand 800W
transformer.
What makes you think that ?

The Behringer web site literature.

Can you post a link ?

That makes them liars.


The little red hedgehog sticker indicates the manufacturer is Toroid
International.
They have Asian factories in India, Sri Lanka and working on one in China
too I
think.
They have no US facilities to the best of my knowledge.
See http://www.toroid.co.uk/ or http://www.toroid.se/english/

I'll take your word for it.

I doubt very much that the EP2500 uses a smaller one. However if you
expect
to get 2400W RMS continuous from one of these amps, you will be
disappointed.

Says who ?

In the short term at least - transformers such as these can deliver much
more
than their continuous VA rating would indicate.

That's why I said "RMS **CONTINUOUS**".
Having trouble reading?

Those amps *will* deliver RMS CONTINUOUS outputs - at least for maybe 1/4 - 1/2
hour perhaps. Usually the heatsink get so hot and causes the amp to shut down
temporarily, thus avoiding transformer overheating too.

Real audio does not require rms continuous operation. Almost no audio amplifier
is designed to provide continuous full power sinewave output these days. Very
few ever were so capable !

snip

Those are 12,000 uF caps in the RMX2450. Not big enough ?

I was referring to the Behringer, but since you asked NO.

So what *would* be big enough in your opinion and why isn't 12,000uF enough ?

Graham

Arny Krueger wrote:

"TonyP" wrote in message
u
"Pooh Bear" wrote in message
...
TonyP wrote:


I doubt very much that the EP2500 uses a smaller one. However if
you expect to get 2400W RMS continuous from one of these amps, you
will be disappointed.

Says who ?

In the short term at least - transformers such as these can deliver
much more than their continuous VA rating would indicate.


That's why I said "RMS **CONTINUOUS**".
Having trouble reading?

There is *continuous* and there is **continuous**. Temperatures in bit power
transformers build up slowly - in minutes and hours. AFAIK, the longest term
standard test of power output is limited to 30 minutes. I've seen
transformers do 30 minutes no sweat, but fail due to thermal stress several
hours later.

Yup, seen that one too. 'Heat soak' is the culprit I think.

Using 'oversize' copper for the windings to keep down I^2*R heating helps a
*lot*.


Graham

"François Yves Le Gal" wrote:

On Mon, 30 Aug 2004 22:09:01 +0100, Pooh Bear
wrote:

Can you post a link ?

The brochure brochure only mentions:

"Oversized power supply

Ultra-reliable, low-noise and highheadroom toroidal power transformer from
the world’s most acclaimed manufacturer TOROID®. You’ll find this brand in
the world’s best and most expensive power amps.

That agrees with what I saw.

I guess someone thought it had to be made in the USA to be good ?


The shielded power transformer with a toroidal core is extremely quiet and
much more musical than a switchmode power supply. It also has an
incredible power reserve to assure that your amp delivers full and tight
bass no matter how much you crank it up".

Hmmm - I wonder - how do they measure how much more musical a toroid is ?


Graham ;-)

Arny Krueger wrote:

"Eric K. Weber" wrote in message


Are they silly enough to run the transformers at 60HZ?

In this case, yes. This is still common with low-end power amps. QSC has
been a leader in the area of building amps with switchmode and stepped power
supplies, but those are all in higher-end amps.

With switching power supplies they may be much higher and require less
core material.... preferably well above 20khz....

The electronics to drive the transformers aren't exactly free.

In fact those big IGBTs and ultra-fast rectifiers aren't cheap. Nor the rest of
the support circuitry. 2 sets of DC storage caps ( instead of 1 ) required too.

More and more
applications have been flipped into switchmode operation as times wear on,
and the driving electronics get cheaper. It's obviously only a matter of
time...

It's going that way - but SMPS still requires expensive ac line filtering to
meet EMC regs that traditional supplies don't. That's a significant extra
expense that won't go away.


Graham

"Arny Krueger" wrote in message ...

There is *continuous* and there is **continuous**. Temperatures in bit power
transformers build up slowly - in minutes and hours. AFAIK, the longest term
standard test of power output is limited to 30 minutes. I've seen
transformers do 30 minutes no sweat, but fail due to thermal stress several
hours later.

For fun, I looked up the heat capacity of copper, and on back of
envelope, figured that the 1500 Watt behringer amp, run at rated
power, should bring its 800 Watt power transformer up to 105 degrees C
in just over five minutes. Of course this was naturally based on lots
of assumptions.

I also looked up the FTC power rating standard -- it calls for a
period of preconditioning at 1/8 rated power, followed by 5 minutes at
rated power.

I would say that unless the vendor claims a continuous power rating,
you can expect a power amp to survive for 5 minutes at rated power.
Hopefully, the protection circuits will shut everything down before
the smoke gets too thick, but it is notable that there is no
temperature sensor on the power transformer in any of these amps.

One vendor, Carvin, claims their power ratings are for continuous use.
But maybe that is overkill. In any event, it seems like we are at the
mercy of engineers making assumptions about the conditions under which
an amp will be operated. This does not give me a lot of confidence in
a market that is so price-driven as music gear.

"Geoff Wood" -nospam wrote in message
...
I was under the impression the offending mixer was withdrawn from sale in
the USA.....

This has been covered in detail here many times, by people far more
knowledgeable of the case than me. I suggest you do a google search.

TonyP.

"Arny Krueger" wrote in message
...
"TonyP" wrote in message
u
"Pooh Bear" wrote in message
...
TonyP wrote:

I doubt very much that the EP2500 uses a smaller one. However if
you expect to get 2400W RMS continuous from one of these amps, you
will be disappointed.

Says who ?

In the short term at least - transformers such as these can deliver
much more than their continuous VA rating would indicate.


That's why I said "RMS **CONTINUOUS**".
Having trouble reading?


There is *continuous* and there is **continuous**. Temperatures in bit
power
transformers build up slowly - in minutes and hours. AFAIK, the longest
term
standard test of power output is limited to 30 minutes. I've seen
transformers do 30 minutes no sweat, but fail due to thermal stress
several
hours later.

Sure, and how many amplifiers can get over 2400W from an 800W transformer
for 30 minutes?

TonyP.

Detector195 wrote:

"Arny Krueger" wrote in message ...

There is *continuous* and there is **continuous**. Temperatures in bit power
transformers build up slowly - in minutes and hours. AFAIK, the longest term
standard test of power output is limited to 30 minutes. I've seen
transformers do 30 minutes no sweat, but fail due to thermal stress several
hours later.

For fun, I looked up the heat capacity of copper, and on back of
envelope, figured that the 1500 Watt behringer amp, run at rated
power, should bring its 800 Watt power transformer up to 105 degrees C
in just over five minutes. Of course this was naturally based on lots
of assumptions.

Including the gauge of the copper windings no doubt.

I actually have *extensive* experience of designing power transformers for use at 50/60Hz for power
amplifiers ( with the same company as used by QSC and Behringer too as it happens ) and I know how
to design for *far* more capacity than you would credit by looking at the thing.

Some of my designs have been run for *months* non-stop - with low dynamic range ( rave ) music
signal at a level sufficient to briefly illuminate the clip leds fairly regularly without ever
faltering. And that's with a transformer you would conventionally call 'undersized'. There's no
substitute for a 'real world' test. Sinewave continuous tells you little of any value. Any amp can
deliver sinewave continuous for 1,2,4,8,15 etc minutes. It's how it performs with music that
counts.

Don't assume a stock catalogue power transformer is the same as a custom one.


I also looked up the FTC power rating standard -- it calls for a
period of preconditioning at 1/8 rated power, followed by 5 minutes at
rated power.

I would say that unless the vendor claims a continuous power rating,
you can expect a power amp to survive for 5 minutes at rated power.
Hopefully, the protection circuits will shut everything down before
the smoke gets too thick, but it is notable that there is no
temperature sensor on the power transformer in any of these amps.

That's reserved for beefier amps.

The QSC RMX series will shut itself down due to heatsink overtemperature before transformer
overheating is an issue.

My more recent designs incorporate auto-resetting overtemp sensors in the TX itself as a 'long
stop'.

One vendor, Carvin, claims their power ratings are for continuous use.
But maybe that is overkill. In any event, it seems like we are at the
mercy of engineers making assumptions about the conditions under which
an amp will be operated. This does not give me a lot of confidence in
a market that is so price-driven as music gear.

It's those assumptions - and how different companies treat them, that make amplifiers different.
Trouble is - these days price seems to be King !

Then ppl complain - but you can't have it both ways. You *do* have to pay a little more for real
quality and reliability. That's why my latest amps have one serious heatsink and fan *per channel*,
not a shared arrangement.


Graham

"Pooh Bear" wrote in message
...
TonyP wrote:
I doubt very much that the EP2500 uses a smaller one. However if you
expect
to get 2400W RMS continuous from one of these amps, you will be
disappointed.

Says who ?

In the short term at least - transformers such as these can deliver
much
more
than their continuous VA rating would indicate.

That's why I said "RMS **CONTINUOUS**".
Having trouble reading?

Those amps *will* deliver RMS CONTINUOUS outputs - at least for maybe
1/4 - 1/2
hour perhaps. Usually the heatsink get so hot and causes the amp to shut
down
temporarily, thus avoiding transformer overheating too.

I will bet the transformer has a thermal fuse. The heatsinks are fan cooled.
At full continuous output the power tansistors do NOT produce maximum heat,
but do so at much lower output power.
I have never had a problem with mine.

Real audio does not require rms continuous operation. Almost no audio
amplifier
is designed to provide continuous full power sinewave output these days.
Very
few ever were so capable !

That's what I said already in the part you snipped. People who understand
audio will be very satisfied at the price.

Those are 12,000 uF caps in the RMX2450. Not big enough ?

I was referring to the Behringer, but since you asked NO.

So what *would* be big enough in your opinion and why isn't 12,000uF
enough ?

For an amp with such high peak current ability, I would prefer more. But I'm
sure they are adequate for most people and most purposes. If costs are to be
cut somewhere, it's one I can live with.

I thought YOU were the one questioning the performance though?

TonyP.

TonyP wrote:

"Pooh Bear" wrote in message
...

Those amps *will* deliver RMS CONTINUOUS outputs - at least for maybe
1/4 - 1/2
hour perhaps. Usually the heatsink get so hot and causes the amp to shut
down
temporarily, thus avoiding transformer overheating too.

I will bet the transformer has a thermal fuse.

It hasn't to the best of my knowledge. And my knowledge of Toroid's transformers
is good. Also I didn't see the thermal fuse indicated on the label.


The heatsinks are fan cooled.
At full continuous output the power tansistors do NOT produce maximum heat,

You're once again confusing sinewave measurements with actual audio tests !

Audio amps run hotter - the more output they deliver. Unlike the sinewave theory
- they *don't* run cooler at max output. If in doubt - get some test loads, a
thermocouple and check for yourself !

For Class H output stages this is especaily true.


but do so at much lower output power.
I have never had a problem with mine.

Real audio does not require rms continuous operation. Almost no audio
amplifier
is designed to provide continuous full power sinewave output these days.
Very
few ever were so capable !

That's what I said already in the part you snipped. People who understand
audio will be very satisfied at the price.

Those are 12,000 uF caps in the RMX2450. Not big enough ?

I was referring to the Behringer, but since you asked NO.

So what *would* be big enough in your opinion and why isn't 12,000uF
enough ?

For an amp with such high peak current ability, I would prefer more. But I'm
sure they are adequate for most people and most purposes. If costs are to be
cut somewhere, it's one I can live with.

Reservoir caps are normally sensibly determined by ripple current capability and
power supply ripple voltage requirements. The 'audiophile brigade' have an
obsession with bigger = better, missing the point that it may have no influence
on the result at all.

I thought YOU were the one questioning the performance though?

Me ? I thought it was you. I thought this was simply a comparison of 2
apparently similar amps.


Graham

TonyP wrote:

Sure, and how many amplifiers can get over 2400W from an 800W transformer
for 30 minutes?

The mistake you're making is calling it an '800W transformer'.

The standard product in the catalogue may look that size but there are ways
of extracting more !


Graham

"Pooh Bear" wrote in message
...
TonyP wrote:

Sure, and how many amplifiers can get over 2400W from an 800W
transformer
for 30 minutes?

The mistake you're making is calling it an '800W transformer'.

Not me, the manufacturer. (850W from memory, although I could be wrong)

The standard product in the catalogue may look that size but there are
ways
of extracting more !

Most will end in tears after 30 minutes at 200% overload, not allowing for
amplifier efficiency.

In case you've forgotten, I think the amp is still good value.

TonyP.

"Pooh Bear" wrote in message
...
TonyP wrote:
I will bet the transformer has a thermal fuse.

It hasn't to the best of my knowledge. And my knowledge of Toroid's
transformers
is good. Also I didn't see the thermal fuse indicated on the label.

OK, I may lose that bet :-)

The heatsinks are fan cooled.
At full continuous output the power tansistors do NOT produce maximum
heat,

You're once again confusing sinewave measurements with actual audio tests
!

NOT *ME*. I stated already that the amp is fine for music.

Audio amps run hotter - the more output they deliver. Unlike the sinewave
theory
- they *don't* run cooler at max output. If in doubt - get some test
loads, a
thermocouple and check for yourself !

You are simply changing the test. At maximum sine wave output power, the
output transistors will *NOT* disipate maximum power as I stated. The
transformer will still be required to deliver the power consumed in both the
load and the amplifier though.

I thought YOU were the one questioning the performance though?

Me ? I thought it was you.

See what happens when you don't read properly.

TonyP.

TonyP wrote:

"Pooh Bear" wrote in message
...
TonyP wrote:

Sure, and how many amplifiers can get over 2400W from an 800W
transformer
for 30 minutes?

The mistake you're making is calling it an '800W transformer'.

Not me, the manufacturer. (850W from memory, although I could be wrong)

I have been to Behringer's site and another poster too.

There is no mention of the transformer being 800W ( or other figure ). If you
have a link - *please* post it.

As I keep repeating, Watts or VA rating for transfomers like this are
misleading. Practical ratings are determined by losses ( copper and iron ).
There are ways to reduce losses that make a custom design way outperform a
'standard product'.

The standard product in the catalogue may look that size but there are
ways
of extracting more !

Most will end in tears after 30 minutes at 200% overload, not allowing for
amplifier efficiency.

You're *assuming* 200% overload. Learn something about transformer design.


In case you've forgotten, I think the amp is still good value.

Which one - or both ?

Graham

TonyP wrote:

"Pooh Bear" wrote in message
...
TonyP wrote:
I will bet the transformer has a thermal fuse.

It hasn't to the best of my knowledge. And my knowledge of Toroid's
transformers
is good. Also I didn't see the thermal fuse indicated on the label.

OK, I may lose that bet :-)

The heatsinks are fan cooled.
At full continuous output the power tansistors do NOT produce maximum
heat,

You're once again confusing sinewave measurements with actual audio tests
!

NOT *ME*. I stated already that the amp is fine for music.

Audio amps run hotter - the more output they deliver. Unlike the sinewave
theory
- they *don't* run cooler at max output. If in doubt - get some test
loads, a
thermocouple and check for yourself !

You are simply changing the test. At maximum sine wave output power, the
output transistors will *NOT* disipate maximum power as I stated. The
transformer will still be required to deliver the power consumed in both the
load and the amplifier though.

For a sinewave test - fine - you're correct. What value is a sinewave test other
than to measure a static THD ?

During sinewave testing the transformer works absolutely OK. I've tested the QSC
- no problem.

These amplifiers aren't designed as servo amps or whatever - they're designed to
reproduce audio. Continuous sinewave tests bear no relation to practical use. (
as I keep repeating ).

I thought YOU were the one questioning the performance though?

Me ? I thought it was you.

See what happens when you don't read properly.

I think it's your mistake actually.


Graham

"Pooh Bear" wrote in message
...
TonyP wrote:
Not me, the manufacturer. (850W from memory, although I could be wrong)

I have been to Behringer's site and another poster too.

There is no mention of the transformer being 800W ( or other figure ). If
you
have a link - *please* post it.

I have had one open. It's marked on the transformer. That's why I said from
memory.
We both agree it is of little consequence for normal use anyway.

In case you've forgotten, I think the amp is still good value.

Which one - or both ?

Probably both, but the Behringer is cheaper.

TonyP.

"Pooh Bear" wrote in message
...
TonyP wrote:
You are simply changing the test. At maximum sine wave output power, the
output transistors will *NOT* disipate maximum power as I stated. The
transformer will still be required to deliver the power consumed in both
the
load and the amplifier though.

For a sinewave test - fine - you're correct. What value is a sinewave test
other
than to measure a static THD ?

During sinewave testing the transformer works absolutely OK. I've tested
the QSC
- no problem.

And I said the Behringer is fine too.

These amplifiers aren't designed as servo amps or whatever - they're
designed to
reproduce audio. Continuous sinewave tests bear no relation to practical
use. (
as I keep repeating ).

As I said all along.

See what happens when you don't read properly.
I think it's your mistake actually.

You would, but you haven't been following things too closely.

TonyP.

TonyP wrote:

"Pooh Bear" wrote in message
...

snip for brevity

During sinewave testing the transformer works absolutely OK. I've tested the
QSC
- no problem.

And I said the Behringer is fine too.

These amplifiers aren't designed as servo amps or whatever - they're
designed to
reproduce audio. Continuous sinewave tests bear no relation to practical
use. ( as I keep repeating ).

As I said all along.

See what happens when you don't read properly.
I think it's your mistake actually.

You would, but you haven't been following things too closely.

Hmmm , so you recant the following post ?


Subject: Behringer amps clones of QSC amps?
Date: Mon, 30 Aug 2004 14:51:07 +1000
From: "TonyP"
Newsgroups: rec.audio.tech
References: 1 , 2 , 3

"The Behringer EP1500 uses a made in USA "Torroid" brand 800W transformer.
I doubt very much that the EP2500 uses a smaller one. However if you expect
to get 2400W RMS continuous from one of these amps, you will be
disappointed."


Graham

Pooh Bear wrote in message ...

These amplifiers aren't designed as servo amps or whatever - they're designed
to reproduce audio. Continuous sinewave tests bear no relation to practical
use. ( as I keep repeating ).

I thought YOU were the one questioning the performance though?

Me ? I thought it was you.

Actually, it was me ;-)

I agree that continous sinewave at rated power is not a musically
realistic test. Other test conditions might be more realistic, but the
manufacturers do not tell us the test conditions. Unless otherwise
stated, it is the FTC test, which is preconditioning at 1/8 of full
power followed by continous sinewave for five minutes. This also bears
no relation to practical use.

My gripe is that there is no way of knowing the range of conditions
under which a power amp can be operated, except by anecdotal evidence
and hoping for the best. Lacking an accepted standard, there can be no
accountability. If an amp goes into protect mode during a gig, was it
under-designed, or over-driven? The manufacturer can always claim the
latter.

It does not require too much cynicism to predict the result of having
no accountability in an industry that is under relentless cost
pressure due to a "dollars per watt" mentality. And the power
transformer seems to be an obvious place to save a few dollars, since
it is a relatively expensive component.

There have been scandals in the past over power ratings, resulting in
the FTC test, for better or worse. Are we ready for another scandal? I
don't know. If today's manufacturers are being honest about power
ratings, it's a safe bet that tomorrow's manufacturers won't be.

Naturally, I am at a loss to say how a power amp should be rated. Why
not give a peak power level plus a continuous power rating? Given the
power transformer size, I would rate the QSC or Behringer at 2400
Watts peak and 400 Watts continuous (half of the power transformer
rating). This is of course with no knowledge of the actual design. But
perhaps a sixfold "crest factor" is appropriate for musical signals.

And by the way, I don't dispute anybody's positive experiences with
that amplifier, nor do I think it is a bad amplifier. I have been
seriously considering their somewhat less powerful but quite
economical 300-Watt bass head.

"Pooh Bear" wrote in message
...
TonyP wrote:
Hmmm , so you recant the following post ?
"The Behringer EP1500 uses a made in USA "Torroid" brand 800W transformer.
I doubt very much that the EP2500 uses a smaller one. However if you
expect
to get 2400W RMS continuous from one of these amps, you will be
disappointed."

Which part? The made in USA, I'm still sure I read in their literature, but
it seems to have been removed.
I may be wrong. I couldn't care less myself.
The transformer is not rated at 2400W continuous, we seem to agree on that.
I also stated IN THE PART YOU SNIPPED, that it is fine for any normal use.

TonyP.

"Detector195" wrote in message
om

I agree that continous sinewave at rated power is not a musically
realistic test. Other test conditions might be more realistic, but the
manufacturers do not tell us the test conditions. Unless otherwise
stated, it is the FTC test, which is preconditioning at 1/8 of full
power followed by continous sinewave for five minutes. This also bears
no relation to practical use.

True, its overkill.

My gripe is that there is no way of knowing the range of conditions
under which a power amp can be operated, except by anecdotal evidence
and hoping for the best.

Actually we do. If a power amp is amplifying music, and not sine waves, then
we know that it is amplifying multitones. If an amplifier is amplifying
mulititones, then we know that the peak-to-average ratio of the signal is 8
dB or more. The peak-to-average ratio of sine waves is 0 dB. The higher the
peak-to-average ratio, the lighter the power supply can be and still be
adequate.

Lacking an accepted standard, there can be no
accountability. If an amp goes into protect mode during a gig, was it
under-designed, or over-driven? The manufacturer can always claim the
latter.

The simple fact that a power amp can deliver rated power with a sine-wave
signal for any appreciable amount of time is pretty solid proof that the
power supply is overbuilt for music.

IME, most power amps that go into protect, do so because they are being
driven into gross distortion, the load is poorly-engineered, or there are
long-term thermal issues.

It does not require too much cynicism to predict the result of having
no accountability in an industry that is under relentless cost
pressure due to a "dollars per watt" mentality. And the power
transformer seems to be an obvious place to save a few dollars, since
it is a relatively expensive component.

This already happens. However, the FTC rules put the brakes on efforts to
get carried away with undersized power transformers. If you can remember
back that far, you will recall that when the FTC rules went into effect,
virtually very tubed power amp, with few exceptions, had to be significantly
derated. IOW, scunging off on the power transformer is an old game. My
recollection is that even tubed amps from well-respected brands like Dyna,
Scott, and Fisher had to be derated to pass FTC-mandated testing. I think
that McIntosh might have been among the few tubed amp manufacturers to skate
through without derating.

There have been scandals in the past over power ratings, resulting in
the FTC test, for better or worse. Are we ready for another scandal? I
don't know. If today's manufacturers are being honest about power
ratings, it's a safe bet that tomorrow's manufacturers won't be.

Two words: car audio.

Naturally, I am at a loss to say how a power amp should be rated. Why
not give a peak power level plus a continuous power rating? Given the
power transformer size, I would rate the QSC or Behringer at 2400
Watts peak and 400 Watts continuous (half of the power transformer
rating). This is of course with no knowledge of the actual design. But
perhaps a sixfold "crest factor" is appropriate for musical signals.

That's pretty close to 8 dB.

And by the way, I don't dispute anybody's positive experiences with
that amplifier, nor do I think it is a bad amplifier. I have been
seriously considering their somewhat less powerful but quite
economical 300-Watt bass head.

Lately, Behringer has been cleaning up their act. Despite all the wailing
and gnashing of teeth, they made some credible stuff all along. For example,
the Ultracurve was always a respectible design, and clearly cloned neither
Mackie or Rane.

François Yves Le Gal wrote:

The shielded power transformer with a toroidal core is extremely
quiet and much more musical than a switchmode power supply. It also
has an incredible power reserve to assure that your amp delivers full
and tight bass no matter how much you crank it up".


http://www.behringer-download.com/_p...P_Folder_e.pdf

"Musical transformer" ?!! ****, I'd prefer a quiet one....

Apart from that, linear power supplies are capable of feeding bigger sudden
transient loads that SMPSs.

geoff

TonyP wrote:
"Pooh Bear" wrote in message
...
TonyP wrote:
Hmmm , so you recant the following post ?
"The Behringer EP1500 uses a made in USA "Torroid" brand 800W
transformer. I doubt very much that the EP2500 uses a smaller one.
However if you expect to get 2400W RMS continuous from one of these
amps, you will be disappointed."

Which part? The made in USA,

As long as they're not ade in India, eh Pooh ? ;-)

geoff

"Arny Krueger" wrote in message ...

Lots of useful information

Thanks. This really helped clear things up for me.

Geoff Wood wrote:

TonyP wrote:
"Pooh Bear" wrote in message
...
TonyP wrote:
Hmmm , so you recant the following post ?
"The Behringer EP1500 uses a made in USA "Torroid" brand 800W
transformer. I doubt very much that the EP2500 uses a smaller one.
However if you expect to get 2400W RMS continuous from one of these
amps, you will be disappointed."

Which part? The made in USA,

As long as they're not ade in India, eh Pooh ? ;-)

geoff

I think Borje prefers the results from the Sri Lankan factory :-)

I certainly did !


Graham