Which power amps (or all of them) have their own sound signatures, and why, by design, or just happened to be?

[PENG]

The impedance an amp actually sees is actually often lower than the impedance on the impedance curve.

Sorry, that would be mathematically and electrically impossible! Impedance = Voltage/Current. For reactive load, it will be a complex number (Z) that has a phase angle as well as a magnitude component, but the magnitude of the impedance is still V/|Z|. Note: |Z| is the absolute value, i.e. the magnitude part of the complex number. (https://www.varsitytutors.com/hotmath/hotmath_help/topics/absolute-value-complex-number )

http://hyperphysics.phy-astr.gsu.edu/hbase/electric/impcom.html

As long as the "impedance" on the "impedance" curve is "impedance" that it obviously is by virtue of the name, then what the amp sees will be the same as what the curve indicate, assuming the curve was plotted based on correctly measured value.

 

[Verdinut]

As for the damping factor spec which amplifier manufacturers publish, we have to assume that the reported figure refers to the DF with an 8 ohm load unless stated otherwise. As it is impedance dependant, so for a 4 ohm speaker the usual claimed figure has to be divided by 2.

 

[TLS Guy]

Sorry, that would be mathematically and electrically impossible! Impedance = Voltage/Current. For reactive load, it will be a complex number (Z) that has a phase angle as well as a magnitude component, but the magnitude of the impedance is still V/|Z|. Note: |Z| is the absolute value, i.e. the magnitude part of the complex number. (https://www.varsitytutors.com/hotmath/hotmath_help/topics/absolute-value-complex-number )

http://hyperphysics.phy-astr.gsu.edu/hbase/electric/impcom.html

As long as the "impedance" on the "impedance" curve is "impedance" that it obviously is by virtue of the name, then what the amp sees will be the same as what the curve indicate, assuming the curve was plotted based on correctly measured value.

I will plead guilty to expressing myself lazily for the sake of brevity. What I was getting at is power factor and heat dissipation in the output devices. This can not be calculated from the impedance curve alone. The phase angle must be taken into account. This is a major factor in why an amp driving a real speaker is so different from driving a resistor on the test bench. This is just one of the reasons why I like my huge tripled output devices in my 909s versus puny receiver output devices.
It is also the reason I design speakers for easier, rather then difficult drive, and will sometimes add components to correct difficult drives, like Raymond Cooke used to do.

This article is a slightly difficult read but it explains well a topic that needs to be understood, and why certain speaker amp combinations can be lethal to amps. It also explains how this issue can blow up bi-polar, MOS FET and class D output stages in different ways.

The bottom line is that the more robust the amp you purchase the less trouble you are likely to have. I have done well with my current dumpers and so I stick with them.

 

[PENG]

I will plead guilty to expressing myself lazily for the sake of brevity. What I was getting at is power factor and heat dissipation in the output devices. This can not be calculated from the impedance curve alone. The phase angle must be taken into account. This is a major factor in why an amp driving a real speaker is so different from driving a resistor on the test bench. This is just one of the reasons why I like my huge tripled output devices in my 909s versus puny receiver output devices.
It is also the reason I design speakers for easier, rather then difficult drive, and will sometimes add components to correct difficult drives, like Raymond Cooke used to do.

This article is a slightly difficult read but it explains well a topic that needs to be understood, and why certain speaker amp combinations can be lethal to amps. It also explains how this issue can blow up bi-polar, MOS FET and class D output stages in different ways.

The bottom line is that the more robust the amp you purchase the less trouble you are likely to have. I have done well with my current dumpers and so I stick with them.

I actually thought you were thinking along that line, thank you for clarifying and in that case we are in agreement.

 

[Grandzoltar]

How does a mark levinson amp cost 20,000. What components inside this thing justifies such a cost. Has anyone ever heard one. Was it a life changing experience. Lol

 

[lovinthehd]

Mark Levinson is just a Samsung brand now....if you want something with real appeal you need something like a pair of the D'Agostino Relentless Monoblock amps, only 485 lbs each (or I also saw 570lbs each) and a mere $250k for the pair. I'm sure they sound fine and will drive just about any speaker you can think of...so they're keepers apparently

 

[PENG]

How does a mark levinson amp cost 20,000. What components inside this thing justifies such a cost. Has anyone ever heard one. Was it a life changing experience. Lol

I think you know the answer lol.

There are plenty of such examples, and this review apparently has an answer to you question, but for the Boulder monoblock amps:

http://www.tonepublications.com/review/boulder-3050-monoblock-amplifiers/

What do you get for a whopping $205,000 dollars? You get real music, provided you have speakers and ancillaries up to the task.

 

[lovinthehd]

I think you know the answer lol.

There are plenty of such examples, and this review apparently has an answer to you question, but for the Boulder monoblock amps:

http://www.tonepublications.com/review/boulder-3050-monoblock-amplifiers/

What do you get for a whopping $205,000 dollars? You get real music, provided you have speakers and ancillaries up to the task.

LOL always the push that you need even more expensive stuff to enjoy expensive stuff...

 

[Phase 2]

How does a mark levinson amp cost 20,000. What components inside this thing justifies such a cost. Has anyone ever heard one. Was it a life changing experience. Lol

I guess maybe so he can ride around in his Bentley? Lol. No but really, what's in those high, higher end amps? Oh to be wealthy!

 

[PENG]

LOL always the push that you need even more expensive stuff to enjoy expensive stuff...

My problem with the real music things is that probably most of the more popular real music were played through, as well as recorded and mixed with a lot of electronics gear not considered by the audiophiles/golden ears as high end to begin with.

 

[Verdinut]

How does a mark levinson amp cost 20,000. What components inside this thing justifies such a cost. Has anyone ever heard one. Was it a life changing experience. Lol

Oh Yeah! The guy bought one and his wife left him. It really changed his life!

 

[PENG]

Oh Yeah! The guy bought one and his wife left him. It really changed his life!

Did she get to take one of the 2 channel?

 

[mtrycrafts]

LOL always the push that you need even more expensive stuff to enjoy expensive stuff...

Well, if it is cheaper, how can you enjoy even more expensive stuff?
A self fulfilling prophesy.

 

[mtrycrafts]

Where are the specs on those Boulders?

And, oh yes, the music is under great pressure at 400+ lbs so they sound great.

 

[Verdinut]

And you definitely need those heavy towers and subwoofers to go with them! You also need a concrete floor.

 

[PENG]

Where are the specs on those Boulders?

And, oh yes, the music is under great pressure at 400+ lbs so they sound great.

Sit a couple of bridged Benchmark amps or AT522NC on top of polished 200 lbs each real boulders you are all set to compete well in a DBT.

 

[PENG]

I know THD+N is not a good indicator of sound quality so please do not tell me again. Just for fun though, I found the following THD+N specs of some not too expensive power amps:

Anthem P2: 325/500WPC/8/4 ohms: continuous RMS, 20 Hz to 20 kHz, <0.1% THD, one or all channels driven.
ATI: <0.03%
Bryston: ≤0.005% Full bandwidth, at rated output, all channel driven.
Krell Duo 300 XD: <0.045% at 1 kHz, at 400 W, 8 Ω, <0.17% at 20 kHz, at 400 W, 8 Ω
Passlab class AB XA series: 1% at 1 kHz, full power
McIntosh monoblocks: 0.005%
Classe CA-2300: <0.002% at 1 kHz balanced, <0.004% at 1 kHz single ended
Parasound Halo JC-1: 0.15% at rated output

Expensive ones:
Boulder 3060: 0.003% full bandwidth, rated output
Goldmund Telos 5000: 0.0005% full bandwidth, rated output (presumably, for a million dollar welder)

So far I couldn't find anything with better THD+N specs than the ABH2:

< 0.0003 % THD+N at full rated power, 20 Hz to 20 kHz

The second best appear to be Bryston and McIntosh SS amps, based on specs, not bench tests.

 

[Kvn_Walker]

I think you know the answer lol.

There are plenty of such examples, and this review apparently has an answer to you question, but for the Boulder monoblock amps:

http://www.tonepublications.com/review/boulder-3050-monoblock-amplifiers/

What do you get for a whopping $205,000 dollars? You get real music, provided you have speakers and ancillaries up to the task.

I'll never be able to afford real music. That makes me sad.

 

[PENG]

I'll never be able to afford real music. That makes me sad.

Can you afford to buy a ton of season tickets to nearby live concert halls?

 

[bombadil]

I normally stay out of amplifier or other electronic gear discussions. Others, such as yourself, are much better qualified to read & understand reviews like in the link. I don't doubt any of the measurements and gee whiz performance graphs shown in the review; that amp is probably well designed and well made. But is it worth $3000?

I wonder why the reviewer received two samples. Is Benchmark quality control questionable? Did Benchmark intend for the reviewer to keep one? (Yes, I'm cynical.)

To directly answer your question, I am fairly certain that golden ear listeners could not tell which amp is which, if the listening test were done properly. In fact, I'd bet the mortgage that listeners could not tell this Benchmark amp from other well made amps of similar power.

The main reason why I stay away from discussions of home audio electronic gear in general is that they avoid the obvious point, that speakers are where the rubber hits the road. Not amps or other electronic gear.

The reviewer at ASR was having trouble measuring the first amp, turned out it was his testing equipment that was at fault. In the meantime the company sent another unit just in case. This is all described in the first paragraph of the review which apparently you did not read.