Do all amplifiers sound the same thread

[Gordonj]

I don't think you need a switcher to hear what I see SO many people decry as a 'Night and Day' difference. Just by their prose it should be instantly and easily distinguishable.

I have a feeling if you were to toss their amp in a black box so they couldn't see it and swap it out sometime in the near future with a like comparable, competent, correctly designed amp for their speakers. Well they wouldn't be able to tell you when the switches where made.

Remember the efficacy of the protocol / procedure needs only to be as focused as the claims.

True... but then we would not be able to play....

 

[jinjuku]

True... but then we would not be able to play....

Not sure what you mean.

 

[lsiberian]

My amps always sound better when I'm enjoying a favorite beverage and snack.

 

[Gordonj]

Not sure what you mean.

Just that the whole purpose of the "test" was to be able to switch between the amplifiers so that any given amp could be listened too. So in order to make it a true blind fold test the switching would have to happen quickly and without a volume change or dead air. And the test would have to keep all other sources/components and speakers exactly the same, you know all the fun stuff.

If we just physically switched amps and connections then the test would be more subjective and not "provable"....

Thats all i meant.

 

[jinjuku]

Just that the whole purpose of the "test" was to be able to switch between the amplifiers so that any given amp could be listened too. So in order to make it a true blind fold test the switching would have to happen quickly and without a volume change or dead air. And the test would have to keep all other sources/components and speakers exactly the same, you know all the fun stuff.

If we just physically switched amps and connections then the test would be more subjective and not "provable"....

Thats all i meant.

Just playing Devils advocate. Night and Day differences should survive 100% of what you just posted. That is a 10/10 or 9/10 pick.

 

[Irvrobinson]

Okay I just spent an hour measuring V,I, and recording W (from the VU meters) and can confirm that listening at 10' from the R900 in my 12X16X9 open to an area at least 3X larger, I was getting 75 dB average (approx.) and both calculated and indicated power was approx 1W or less. Cranked up the volume to get about 85 dB average, power seemed to go up 4X, still less than 1W.

So IMHO in my two channel listening environment, the 3805 AVR provides more than the power I need whether it is driving my 86 dB/W/M Energy or the 90 dB/W/M KEF, likely over 99% of the time. That is, all well designed 130 WPC class A/AB amps would likely sound the same to me in that room. I always felt that way, taking measurements simply confirm some of the reasons.

I don't want to go off topic as this thread is not about measurements but I may post them if I start a thread on measurements. For now, PM me if you are interested in the my ad hoc/improvised measurement results using just a Hoiki meter, RS SPL meter and the amp's on board wattmeters. The Hoiki is accurate to +/- 1% for 40 to 1000 Hz. The music used was Diana Krall's album, When I look in you eyes, track 5.

My space is a lot larger than yours, and my speakers 3db less sensitive than your Energy speakers, but as I already posted, on some material *I know* can hear the power difference. Of course, I was measuring 102db+ peaks when I heard it. Probably 90db average volume level at my listening position. I probably couldn't hear differences on a Diana Krall album either (I have every one). Try fusion jazz for a better test.

 

[Gordonj]

Just playing Devils advocate. Night and Day differences should survive 100% of what you just posted. That is a 10/10 or 9/10 pick.

well if it is a night and day differnece I guess someone would say "hey what happened to all my low end.."

 

[Steve81]

Okay I just spent an hour measuring V,I, and recording W (from the VU meters) and can confirm that listening at 10' from the R900 in my 12X16X9 open to an area at least 3X larger, I was getting 75 dB average (approx.) and both calculated and indicated power was approx 1W or less. Cranked up the volume to get about 85 dB average, power seemed to go up 4X, still less than 1W.

Here's the sad part for me:

My room is about 2500 cubic feet, and I sit a bit under 9 feet from my mains, which have a rated sensitivity of 99dB w/ 2.83V (realistically closer to 95dB anechoic), and a minimum impedance of 4 ohms per the manufacturer. The situations where I need more than a single watt per channel, even assuming my speakers spend more time at 4 ohms than above, are far and few between. My receiver is THX Select 2 rated, meaning it is specified to deliver a 12.5 ampere peak into a 4 ohm load on the front channels (which equates to 625 watts into 4 ohms).

In spite of all this, I still want a separate amplifier; and you know, if I do get one, I'm sure I'll hear a night and day difference too

 

[Irvrobinson]

Here's the sad part for me:

My room is about 2500 cubic feet, and I sit a bit under 9 feet from my mains, which have a rated sensitivity of 99dB w/ 2.83V (realistically closer to 95dB anechoic), and a minimum impedance of 4 ohms per the manufacturer. The situations where I need more than a single watt per channel, even assuming my speakers spend more time at 4 ohms than above, are far and few between. My receiver is THX Select 2 rated, meaning it is specified to deliver a 12.5 ampere peak into a 4 ohm load on the front channels (which equates to 625 watts into 4 ohms).

In spite of all this, I still want a separate amplifier; and you know, if I do get one, I'm sure I'll hear a night and day difference too

Get a single-ended tube amp, and then you might hear a difference!

My previous speakers were almost like that. One way they did differentiate between electronics was the noise level, not that it affected music. Not so much amps either, but pre-amps.

 

[Gordonj]

So just for fun here is one possible way to conduct an A/B test of amps. The attached pdf shows a very simple CAD drawing that should work. Note the Amp Switcher is a Russound AB-2.2 ($83) and the D/A is the RDL UDA-4 ($200).

This would allow the same source to feed both amps and then the amp outputs to be switched/selected to the test speakers. The possible problem with this approach is the fact that the entire test resides on the quality of the amp selector. That could be a problem....

RU-UDA4 ‐ Stereo Audio Distribution Amplifier ‐ 2x4 ‐ RCA jacks

Speaker Selectors - Table Top, Dual Source Selector AB-2.2

 

[jinjuku]

So just for fun here is one possible way to conduct an A/B test of amps. The attached pdf shows a very simple CAD drawing that should work. Note the Amp Switcher is a Russound AB-2.2 ($83) and the D/A is the RDL UDA-4 ($200).

This would allow the same source to feed both amps and then the amp outputs to be switched/selected to the test speakers. The possible problem with this approach is the fact that the entire test resides on the quality of the amp selector. That could be a problem....

RU-UDA4 ‐ Stereo Audio Distribution Amplifier ‐ 2x4 ‐ RCA jacks

Speaker Selectors - Table Top, Dual Source Selector AB-2.2

I would rather get a Pro-Audio sound interface that has 4 out. Just route it in the Software Patch/Mixing board.

D/A wouldn't come into question especially if it's Apogee, Lynx, or RME.

 

[Gordonj]

I would rather get a Pro-Audio sound interface that has 4 out. Just route it in the Software Patch/Mixing board.

D/A wouldn't come into question especially if it's Apogee, Lynx, or RME.

Sure at much more the cost. Several hundreds to thousands vs. a few hundred. No problem. Just trying to keep it something that everyone could do relatively inexpensive and simply.

Sorry misread. I agree get a higher quality D/A and problems start going away. The great things is one can plug in any D/A or speaker selector that they feel is best or that they would like to spend money on.

 

[jinjuku]

Sure at much more the cost. Several hundreds to thousands vs. a few hundred. No problem. Just trying to keep it something that everyone could do relatively inexpensive and simply.

Sorry misread. I agree get a higher quality D/A and problems start going away. The great things is one can plug in any D/A or speaker selector that they feel is best or that they would like to spend money on.

Several for under $600. If members here are serious about some realistic A/B I'll even pick it up. The nice thing about a lot of these interfaces is that they are configurable for balanced and single ended applications. Makes gain staging a breeze.

 

[Gordonj]

Several for under $600. If members here are serious about some realistic A/B I'll even pick it up. The nice thing about a lot of these interfaces is that they are configurable for balanced and single ended applications. Makes gain staging a breeze.

That addresses the input side to the amps (the sources). The output switching of the amps is the bigger challenge not the source D/A.

 

[Hobbit]

One way to "see" the differences in amps would be to get (you can rent) a spectrum analyzer and a sweepable sinusoidal frequency generator and a programable noise generator. Both that output freqs throughout the entire audible range. Set these up to run directly into your amp. Then mount the transducer (mic) in the one spot in the room, adjust the volume (use your RS SPL meter at a mid freq) at that location to a normal listening level....

Then overlay the waveforms from both amps to see the difference. Perhaps do this at a low, medium, and high listening level (personally, I wouldn't care about extremes either way). You may see some flaws in your speakers, but these would be the same for both amps.

 

[Irvrobinson]

I don't think you need a switcher to hear what I see SO many people decry as a 'Night and Day' difference. Just by their prose it should be instantly and easily distinguishable.

I agree. IMO, the only differences that will be revealed by A/B comparisons are ones so obvious, like amps demonstrating clipping or soft-clipping compression, that you hardly need the A/B test in the first place.

DBTs are another issue altogether, and for audio I hate them.

 

[3db]

Is it accurate to summarize then that there is no difference in sound among amps driving the same load well within their power envelope and that the differences only start to show once they being pushed...mean either load applied or increased SPL?

 

[Irvrobinson]

Is it accurate to summarize then that there is no difference in sound among amps driving the same load well within their power envelope and that the differences only start to show once they being pushed...mean either load applied or increased SPL?

Personally, I think there are subtle differences in sound between amps, but listening for them in A/B test, or especially a DBT, is very difficult. I also think the amps tested need to be much more different than was the case in the silly testing I described earlier in this thread. Like if I used a $500 AVR rather than just another high quality amp from the same manufacturer. Even so, I'd be unlikely to take any A/B or DBT bets on amps. It's too difficult a problem, and in my experience frustrating more than revealing.

 

[jinjuku]

Personally, I think there are subtle differences in sound between amps, but listening for them in A/B test, or especially a DBT, is very difficult. I also think the amps tested need to be much more different than was the case in the silly testing I described earlier in this thread. Like if I used a $500 AVR rather than just another high quality amp from the same manufacturer. Even so, I'd be unlikely to take any A/B or DBT bets on amps. It's too difficult a problem, and in my experience frustrating more than revealing.

I would have said not worth the cost premium

 

[Steve81]

Is it accurate to summarize then that there is no difference in sound among amps driving the same load well within their power envelope and that the differences only start to show once they being pushed...mean either load applied or increased SPL?

Nah; you can engineer an amplifier to have a sound.

Edit: Also the sections regarding amplifier sounds here are worth a quick read:

http://www.roger-russell.com/truth/truth.htm