Can you hear a difference in Sound between Audio Amplifiers?

[jinjuku]

BTW J.D at Peavey is keeping an eye out for a prototype Crest MA400 amp from the 90's that was stolen out of his truck. The production models were utilizing IGBT's in the output stage but his prototype was using MOSFETS. So if you see a Crest MA400 with FET's in them drop me a line here, or sickandneedhelp at AVSForum.

He sure would like it back.

 

[PENG]

Agreed. To be honest, I was surprised by my first structured comparison testing experience. (Back in the late 1980s, SBT, with CD players.) It is really easy to get confused, a reaction I didn't expect.



I'm as cautious as you are, frankly. And my system sounds different to me on different days. Sometimes I just have to leave it off for a day or two. Nonetheless, to me at least, the fatigue effect seems real. I keep searching for hints of measurements that might support my theory, because if it can't be measured it doesn't exist.

This is scarely, nothing in you post I can take issue or have doubt about...... I actually have similar experience, it was after those kind SBT of different components I stop paying attention to what 3 dB referred to as "fluff" words found on forums and professional reviews and focus only on the measurements that came with those reviews. Even measurements need to be taken with a grain of salft for many reasons.

 

[PENG]

Again, I say there are some differences however, the discussions is better spent on speakers and DAC's and all those DSP's that people use on their systems. All that will effect the sound much more then a given amp change.

Buy the best amp that you can afford that meets the load requirements that you have and be done with it.

Except DAC's, in my opinion that's like amps in the sense that once you reach that not too hard to reach point of diminishing returned (specs and price), DAC's make no audible difference to normal human beings. So I'd say get an amp that has more than the power you need, with better than average specs, preferably verified by lab measurements, and a well spec'd media player and then just focus on high quality media, speakers, and so on.

 

[RichB]

Except DAC's, in my opinion that's like amps in the sense that once you reach that not too hard to reach point of diminishing returned (specs and price), DAC's make no audible difference to normal human beings. So I'd say get an amp that has more than the power you need, with better than average specs, preferably verified by lab measurements, and a well spec'd media player and then just focus on high quality media, speakers, and so on.

I agree. What surrounds the DACs matters as much or more than the DAC itself.
These days if you do not have a 32-bit DAC it cannot be high-end.
There may be some truth to that (For example: Digital Volume control) , but Oppo designs the power supply to support finicky DACs like the SABRE 32 included in the 105.
After the DAC, there are the OpAmps (HDAM for Marantz).
So you will often read, "are the DACs better in the Oppo or the XYZ processor", but it is the complete implementation that matters.

Thankfully, this can be measured.

What is not often measured is the transmission of LPCM which can be problematic.
There are differences in the sound procedure via the BDP-105 on my system transmitted analog, HDMI, and COAX sound into the AV8801.
I am not certain why, but I suspect it is the handling of the LPCM data stream (clocking) over HDMI. This may not a priority of the chip providers.

I'd love to see an LCPM source of frequency sweeps played on an Oppo that measured at the Preamp Outs.
This would tell us how the chain performs with different transmission methods.

- Rich

 

[AcuDefTechGuy]

Except DAC's, in my opinion that's like amps in the sense that once you reach that not too hard to reach point of diminishing returned (specs and price), DAC's make no audible difference to normal human beings. So I'd say get an amp that has more than the power you need, with better than average specs, preferably verified by lab measurements, and a well spec'd media player and then just focus on high quality media, speakers, and so on.

I agree. What surrounds the DACs matters as much or more than the DAC itself.
These days if you do not have a 32-bit DAC it cannot be high-end.
There may be some truth to that (For example: Digital Volume control) , but Oppo designs the power supply to support finicky DACs like the SABRE 32 included in the 105.
After the DAC, there are the OpAmps (HDAM for Marantz).
So you will often read, "are the DACs better in the Oppo or the XYZ processor", but it is the complete implementation that matters.

Thankfully, this can be measured.

What is not often measured is the transmission of LPCM which can be problematic.
There are differences in the sound procedure via the BDP-105 on my system transmitted analog, HDMI, and COAX sound into the AV8801.
I am not certain why, but I suspect it is the handling of the LPCM data stream (clocking) over HDMI. This may not a priority of the chip providers.

I'd love to see an LCPM source of frequency sweeps played on an Oppo that measured at the Preamp Outs.
This would tell us how the chain performs with different transmission methods.

- Rich

Yeah, if we look at the specs of the low end DAC vs flagship models, we see that the low end has a SNR of 112dB and the flagship has a SNR of 132dB. All the other specs like Crosstalk and THD may also be slightly better.

But who can tell the difference between a SNR of 112dB vs 132dB ? Who can tell the difference between a XTalk of -110dB vs -100dB ?

As long as the implementation is solid, I also believe we cannot tell any significant difference among DACs.

 

[Gordonj]

Except DAC's, in my opinion that's like amps in the sense that once you reach that not too hard to reach point of diminishing returned (specs and price), DAC's make no audible difference to normal human beings. So I'd say get an amp that has more than the power you need, with better than average specs, preferably verified by lab measurements, and a well spec'd media player and then just focus on high quality media, speakers, and so on.

So true. And couldn't we say that for every component at some level? (Each component with its own level of diminishing returns).

 

[fmw]

I answered yes, as amplifiers can undoubtedly sound different depending on the circumstances involved.

Of course, I haven't heard any particular differences in sonic character among my various amplifiers/receivers which include Onkyo, HK, and Emotiva.

So, if you don't know what circumstances would cause a sonic difference and you've never heard a sonic difference, why would you say yes to the poll?

 

[fmw]

Yeah, if we look at the specs of the low end DAC vs flagship models, we see that the low end has a SNR of 112dB and the flagship has a SNR of 132dB. All the other specs like Crosstalk and THD may also be slightly better.

But who can tell the difference between a SNR of 112dB vs 132dB ? Who can tell the difference between a XTalk of -110dB vs -100dB ?

As long as the implementation is solid, I also believe we cannot tell any significant difference among DACs.

Yes, differences in specifications that are beyond audibility are pretty meaningless and don't necessarily make one product a better performer than another in the real world. It is a curious phenomenon that people are swayed by them.

 

[Steve81]

So, if you don't know what circumstances would cause a sonic difference and you've never heard a sonic difference, why would you say yes to the poll?

What makes you think I don't know what circumstances would cause a sonic difference? They're circumstances that other people seem to be writing off (poor design, difficult loads for which a given amplifier is ill suited, etc), but they're still relevant to the question as asked.

 

[fmw]

What makes you think I don't know what circumstances would cause a sonic difference?.

Only that you didn't state them.

 

[Steve81]

Only that you didn't state them.

Not a very good assumption on your part then I suppose

 

[Irvrobinson]

Even measurements need to be taken with a grain of salt for many reasons.

So true, and in so many ways. I find that most people don't understand how easy it is to make measurements look how you want them to look by varying the test parameters. I'm that way with speakers; I'm not expert enough to know what's BS and what isn't.

Measurements in any field often take a lot of expertise to interpret. For example, I know a lot of automobile enthusiasts who think a dynamometer run is definitive in some way, and they worry about differences of a few horsepower. In reality, the test conditions and parameters of the run can make a dyno test vary considerably, and shops with dynos know that if they report higher readings they'll get more future business than shops that report lower readings.

 

[fmw]

Not a very good assumption on your part then I suppose

I suppose.

 

[TLS Guy]

I do think amps sound different, and to some extent that is a mystery to me.

I have just swapped out the A/B amps in our town home for current dumpers I have just made ready (Quad 405 IIs). The sound is definitely a little smoother and more relaxed. To me the current dumping amps produce the least fatiguing sound of any designs I know of.

 

[PENG]

So true. And couldn't we say that for every component at some level? (Each component with its own level of diminishing returns).

I guess that is probably true to a large extent, for electronic components, but for speakers I am not sure where that point/level is, if there is one.

 

[AcuDefTechGuy]

I do think amps sound different, and to some extent that is a mystery to me.

I have just swapped out the A/B amps in our town home for current dumpers I have just made ready (Quad 405 IIs). The sound is definitely a little smoother and more relaxed. To me the current dumping amps produce the least fatiguing sound of any designs I know of.

Oh, so you think amps sound differently, but you think Pure Direct mode sounds exactly the same as Stereo Mode?

Considering the fact that not all Stereo modes are the same due to different processor & circuit designs. For example, the Stereo mode in my 2002 Pioneer Elite processor sucked (back in 2002).

I think the possibility of Pure Direct mode sounding differently than Stereo mode is more likely than the possibility of amps sounding differently.

But I suppose we all have different experiences, so anything is possible.

 

[fmw]

I do think amps sound different, and to some extent that is a mystery to me.
.

It should be no mystery at all. You haven't engaged in a level matched, double blind bias controlled listening test. When you do, you will change your mind about an amplifier sounding "relaxed."

 

[AcuDefTechGuy]

It should be no mystery at all. You haven't engaged in a level matched, double blind bias controlled listening test. When you do, you will change your mind about an amplifier sounding "relaxed."

What about "smoother" or "sweeter" or more "chocolaty".

 

[cpp]

What about "smoother" or "sweeter" or more "chocolaty".

All I know my ATI has that minty fresh articulate sound and my tubes are smoother or sweeter or more chocolaty

 

[RichB]

What about "smoother" or "sweeter" or more "chocolaty".

My new ATI 3005 hasn't even arrived but I have it on good authority that it will be dark chocolaty.
It cannot possibly have air, not with its price tag.
Heft, it has

- Rich