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Do amplifiers really sound the same?

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spxy said:
what are the test you are referring too?

... most of the tests that are often quoted are designed to seek a consensus in a group of listeners and ignore individual results....
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Testing an individual produces data which is valid for that individual and that individual only.

Testing many individuals & setting the benchmark for transparency at levels of distortion etc where, say. 99.9% of the peple tested are happy that transparency has been achieved is valid for 99% of the population.

This has the added advantage that it allows for the 1% of the population who may be able to detect the chosen level of distortion.

It is that 1% who mresumably account for the 100% of audiophiles who hear night and day differences between a Naim amp & a Linn amp:D

Chris
 
john & Jake said:
Hi, this is a new one on me.
I wish to do the straight wire test on my amp tonight could you please tell me how it is done.
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You will need a pre-amp with two identical outputs, the Power Amp under Test, an attenuator, an A-B switchbox, a dummy load and another power amp and 'speakers.

You arrange the output of the pre-amp to go to both the PAuT and switchbox, the output of the switchbox goes to the power amp and 'speakers.

The second input of the switchbox goes to the output of the PAuT feeding the dummy load, through the attenuator such that the A and B parts of the switchbox receive the same signal level, matched to 0.1dB.

Then listen to some music direct, i.e. the A path and switch to the B path in which the signal goes through the PAuT. If this is done blind, and one can't tell whether the switch is direct or going through the PAuT, then the PAuT must be transparent. The dummy load can be a simple resistor, or it can be a complex load to simulate a difficult loudspeaker, or indeed it could be a difficult loudspeaker if that is placed in a separate room such that the noise doesn't affect what is being heard in the listening room.

If when switching A-B on a wide variety of music it can't be identified which is direct and which is through the amplifier, then the PAuT must be transparent.

This test can of course be done with any component.

Quad famously did it by daisy-chaining 50 of their Quad 303s and apart from a bit more noise, which wasn't audible under the music, they were still transparent.

S.
 
If you make a simple passive preamp using a Alps blue and then change the pot for a Noble it sounds different both are 10k then swap the carbon pot for a Dact stepped attenuator it sounds different again then use a Seiden 2 pole 43 way switch and its different again then change the shunt resisters and it sounds different again and that's just a simple passive preamp and all that's changed is the pots.

Capacitors sound different how you lay out the amp affects its sound the power supply has a huge effect on sound the case used to house it effects the sound.
 
john dolan said:
If you make a simple passive preamp using a Alps blue and then change the pot for a Noble it sounds different both are 10k then swap the carbon pot for a Dact stepped attenuator it sounds different again then use a Seiden 2 pole 43 way switch and its different again then change the shunt resisters and it sounds different again and that's just a simple passive preamp and all that's changed is the pots.

Capacitors sound different how you lay out the amp affects its sound the power supply has a huge effect on sound the case used to house it effects the sound.
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John,

You are simply never.ever going to acknowledge that listening to different bits of kit when you know what you are listening to is simply an unreliable method of looking for differences, are you?

Chris
 
Mescalito said:
John,

You are simply never.ever going to acknowledge that listening to different bits of kit when you know what you are listening to is simply an unreliable method of looking for differences, are you?

Chris
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In the same way that the measuristas will never admit that using a scope is a poor way of determining how something sounds....
 
When I built my first serious (in money terms) system I already understood that the speakers were key (I had Yamaha NS1000Ms which a friendly dealer had sold me for peanuts some years before). I was unsurprised by the huge difference a Roksan Xerxes RB300 made. The real surprise was the difference that replacing a NAD3020 with a Naim 32.5/140 made.

Nic P
 
Dik Dolan said:
In the same way that the measuristas will never admit that using a scope is a poor way of determining how something sounds....
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The difference, of course is that there is a large body of evidence from all sorts of fields showing that sighted evaluation of anything is fundamentally unreliable.

Just as there is a large body of evidence supporting the "if it don't measure differently, it aint different" argument.

Your assertions, however , rely purely on just that. Your assertions. And assertions bty other true believers.

Chris
 
It's my assertion that everything is fundamentally unreliable when it comes to assessing most things.
My 'scopes and distortion analyser tell me something works, not how it will sound. Blind tests seem all the rage when they prove "your" points of view, but get dismissed when someone like choice magazine claim to reliably identify different amps, as mentioned several times.
I chose to measure to find out if something is functional, then listen (sighted) to evaluate if I actually like it. Often this can take weeks to fully come to grips with how I feel about something and even then I reserve the right to change my mind later on. There are no absolutes... I've often chosen the less expensive "thing" over the flashier or more expensive one, so it's not as simple as £= better or x measures better therefore I'll take that one..
 
Dik Dolan said:
It's my assertion that everything is fundamentally unreliable when it comes to assessing most things.
My 'scopes and distortion analyser tell me something works, not how it will sound. Blind tests seem all the rage when they prove "your" points of view, but get dismissed when someone like choice magazine claim to reliably identify different amps, as mentioned several times.
I chose to measure to find out if something is functional, then listen (sighted) to evaluate if I actually like it. Often this can take weeks to fully come to grips with how I feel about something and even then I reserve the right to change my mind later on. There are no absolutes... I've often chosen the less expensive "thing" over the flashier or more expensive one, so it's not as simple as £= better or x measures better therefore I'll take that one..
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That's true to a great extent, but if the measurements are good, i.e. they indicate transparency, then how it sounds will also be obvious, it won't have one. Equally, if the measurements indicate the lack of transparency, then again, depending on what the measurements show, they give a pretty good indication of what the thing will sound like. Ultimately, one either likes transparency, or one prefers the sound of something with its own character. This second possibility can be found only by listening, but the right measurements can eliminate that which will be least suitable to achieving the desired sound.

S
 
Do any amplifier designers not use their ears in subjective testing in the final stages of tweaking their products?

Nic P
 
hammeredklavier said:
Then they must be very very quiet!
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The 303 is pretty quiet. but daisy-chaining 50 of them must have increased the noise considerably. According to PW, the noise was comparable to that of a good Reel to Reel recorder, so audible between passages, but he claimed, inaudible under music such that the whole caboodle passed the SWBT.

Each 303 had an attenuator on the output such that each 303 got the same signal level as the first, thus attenuating the noise by the same amount.

It was done for one of their advertisments, and they managed to convince the ASA it was kosher.

S.
 
Just wondering how many of you it all sounds the same guys are over 60 and how do you think your hearing compares to a 20 year old.
 
Nic P said:
Do any amplifier designers not use their ears in subjective testing in the final stages of tweaking their products?

Nic P
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Sorry to keep harking back to Peter Walker, but in an interview with Ken Kessler reported in KK's book on Quad, PW said they never listened to music as part of the design process only test tones and other "funny noises" and then for audibility of certain effects.

When I was designing Broadcast Audio equipment, I would have been laughed out of the AES if I'd designed "by ear". By all means listen to the finished result as a sort of reality check or final "well done" to oneself, but as to listening to capacitors, (or even solder...) no.

S.
 
john dolan said:
Just wondering how many of you it all sounds the same guys are over 60 and how do you think your hearing compares to a 20 year old.
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As one gets older, one's high frequency sensitivity reduces, and indeed, one'soverall sensitivity reduces.

However, to compensate somewhat comes greater experience and descrimination, so older engineers know what to listen for, even if their hearing isn't as acute as the younger ones.

S.
 
Mescalito said:
Yeah, of course they do.

Chris
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I have a hi fi mag from a few years ago that the reviewer did a factory visit and while he was there he noticed a few guys in a corner and when he asked what are those guys doing the manager told him they were testing different solders for sound.

If you don't believe me phone them up and ask them instead of insinuating i just lied about it.
 
serge auckland said:
As one gets older, one's high frequency sensitivity reduces, and indeed, one's overall sensitivity reduces.

However, to compensate somewhat comes greater experience and discrimination, so older engineers know what to listen for, even if their hearing isn't as acute as the younger ones.

S.
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If your over 60 and think everything sounds the same don't you even consider you might not have good hearing and in fact things might sound different but you cant hear it.

Experience gains you nothing if your mutton.
 
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