Are differences just in our heads or just mine?

[sq225917]

Steady state measurements on amps into fixed loads tell you bugger about how they 'sound' and a little about how they measure.

To measure how they sound they have to measuring the output from the front of the speaker they are attached to, you can't measure an amp in isolation, it will perform differently into every different model of speaker.

The general measurements THD, TID,, blah blah tell you nothing about how an amp sounds. They tell you nothing about it's ability to recreate an accurate soundstage, depth and height. To learn that you have to breakdown the output from the front of the speaker capture it with two very fast A-D converters and then analyse that to see how it sounds and correlate those results to how we process sound.

No one does anything like that.

 

[Robert]

I believe I hear a difference with amplification, I wish I did not, it would be cheaper.

The vast majority of audiophiles believe they hear differences between amplification where measurement would indicate this to be highly unlikely.
Only when some controls are introduced into the listening session, including blind comparisons does this belief start to weaken.

Most audiophiles actually want to hear these differences and want more expensive to = better. Thats's why these daft and spurious arguments about blind testing being stressful get thrown up.

The day there is acceptance you can pop to Richer Sounds and spend £500 on a a near perfect amplifier we have the end of a huge section of this hobby, and a section of the industry to go with it.
Vested interests exist at all levels, including the enthusiast audiophile sitting at the end of the chain.

Needn't happen this way of course.
We could go back to differentiating amplifiers on the provision of facilities, build quality (look and feel) and power.
lets have more inputs and for god safe lets include a proper digital input so that, finally, in 2011 digital becomes just another input like aux, Cd, tuner etc.

 

[stevec67]

I don't know how the lottery works and I've never played it... If that's not what you meant, then what did you mean?

The lottery is that you have 49 numbered balls and you draw out 6, one after the other. If you guess all or most of them, you win. The point is that the odds of any 6 ball combination are the same as any other, so 1-6 (in any order) is just as likely as 41-46 (any order), any other unordered combination or indeed what came up last week. This is at odds with what you'd guess though, most people bet on it being one or two from 1-10, one or two from 10-20, one or two from 20-30, etc because this is intuitively "correct" while the chances of turning up 1-6 seems intuitively impossible.

 

[Greg]

The vast majority of audiophiles believe they hear differences between amplification where measurement would indicate this to be highly unlikely.
Only when some controls are introduced into the listening session, including blind comparisons does this belief start to weaken.

Most audiophiles actually want to hear these differences and want more expensive to = better. Thats's why these daft and spurious arguments about blind testing being stressful get thrown up.

The day there is acceptance you can pop to Richer Sounds and spend £500 on a a near perfect amplifier we have the end of a huge section of this hobby, and a section of the industry to go with it.
Vested interests exist at all levels, including the enthusiast audiophile sitting at the end of the chain.

Needn't happen this way of course.
We could go back to differentiating amplifiers on the provision of facilities, build quality (look and feel) and power.
lets have more inputs and for god safe lets include a proper digital input so that, finally, in 2011 digital becomes just another input like aux, Cd, tuner etc.

but there are clear reasons why a valve-based design is likely to sound different from a Class A/B SS design and a pure Class A to sound different from a typical SS running in Class B. So really, your point is moot.

 

[Robert]

Steady state measurements on amps into fixed loads tell you bugger about how they 'sound' and a little about how they measure.

To measure how they sound they have to measuring the output from the front of the speaker they are attached to, you can't measure an amp in isolation, it will perform differently into every different model of speaker.

The general measurements THD, TID,, blah blah tell you nothing about how an amp sounds. They tell you nothing about it's ability to recreate an accurate soundstage, depth and height. To learn that you have to breakdown the output from the front of the speaker capture it with two very fast A-D converters and then analyse that to see how it sounds and correlate those results to how we process sound.

No one does anything like that.

That isn't required.

If an amplifier has vanishingly low THD and IMD at middle frequencies but this rises markedly at the extremes it can tell you lots about how the amplifier will perform. Same goes for frequency and phase tests.
Circuit instability, feedback issues, poor power bandwidth, saturation and phase errors in transformer circuits for starters.

What do mean by 'steady state' ?

An AC test signal is not steady state.
AC test signals swing the output between the rails at a prescribed frequency and amplitude - just like music.

What you claim might be true if measuring DC conditions but little else.

 

[Robert]

but there are clear reasons why a valve-based design is likely to sound different from a Class A/B SS design and a pure Class A to sound different from a typical SS running in Class B. So really, your point is moot.

Yes there are Greg - but most people don't use them.
If you want to use electronics to bend sound that is fine, but lets have the causes for the sound change out in the open and not portrayed as is usually the case with 'the magic of valves'.

 

[darrylfunk]

robert out of interest what do you think of dc coupled amplifiers?

 

[Robert]

I don't have a view darryl.
Makes no difference if an amplifier if flat to DC or has the filter corner set just above.
All that concerns me is that the amplifier remains flat to 20hz.

 

[Greg]

Yes there are Greg - but most people don't use them.
If you want to use electronics to bend sound that is fine, but lets have the causes for the sound change out in the open and not portrayed as is usually the case with 'the magic of valves'.

absolutely agree, but what I'm trying to say is that your suggestion (not necessarily your fundamental point) that any well designed £500 amp from RS is basically all anyone is likely to need is really not true given that they are most likely to be Class A in the first few watts, but in Class B most of the time when used. It would be ideal for at least everyone using a forum like this to understand the difference given the explicable reasons why Class B SS amps are not ideal.

 

[norriemal]

An amplifier on its own doesn't make a sound. It has a positive and a negative connection and the circuit is completed by a speaker.

We talk about difficult speakers and loads. So the complexity of the circuit with a speaker in it is what gives us a sound. The better amps cope with these difficult loads to a greater extent and that is why they have the potential to sound better.

Some amp and speaker set ups are generally considered good combinations and that is what we measure with our ears. An amp doesn't have a sound it has an ability to drive a speaker.

 

[Robert]

absolutely agree, but what I'm trying to say is that your suggestion (not necessarily your fundamental point) that any well designed £500 amp from RS is basically all anyone is likely to need is really not true given that they are most likely to be Class A in the first few watts, but in Class B most of the time when used. It would be ideal for at least everyone using a forum like this to understand the difference given the explicable reasons why Class B SS amps are not ideal.

Yes agreed.

I'm thinking more of those inclined to swap one 'blameless' box of SS electronics for another. Or those bloody threads comparing things that you cannot put a cigarette paper between in terms of performance. Seems to be dacs at the moment.

Go out and collect 20 popular solid state amplifiers ranging in price from say £500-£2000 and then get some friends to tell them apart under blind conditions. They'll struggle at best.
These will likely all be boring boxes with the usual inputs so why not be a little different and make these boringly similar sounding amplifiers appeal to different users in terms of ergonomics and ability to have some bespoke element - like proper digital inputs or perhaps some room EQ facility. Charge more according to the additional features and power.

 

[Robert]

An amplifier on its own doesn't make a sound. It has a positive and a negative connection and the circuit is completed by a speaker.

We talk about difficult speakers and loads. So the complexity of the circuit with a speaker in it is what gives us a sound. The better amps cope with these difficult loads to a greater extent and that is why they have the potential to sound better.

Some amp and speaker set ups are generally considered good combinations and that is what we measure with our ears. An amp doesn't have a sound it has an ability to drive a speaker.

You can connect a simulated speaker load (or a real one if you prefer) and then measure the amplifier. A real one would be a bit noisy!
If the performance as measured at the output terminals hasn't changed then there is nothing to worry about - the amplifier is effectively shrugging-off the load.

There is little point measuring an amplifier unloaded.

 

[Greg]

Yes agreed.

I'm thinking more of those inclined to swap one 'blameless' box of SS electronics for another. Or those bloody threads comparing things that you cannot put a cigarette paper between in terms of performance. Seems to be dacs at the moment.

Go out and collect 20 popular solid state amplifiers ranging in price from say £500-£2000 and then get some friends to tell them apart under blind conditions. They'll struggle at best.
These will likely all be boring boxes with the usual inputs so why not be a little different and make these boringly similar sounding amplifiers appeal to different users in terms of ergonomics and ability to have some bespoke element - like proper digital inputs or perhaps some room EQ facility.

Partially, though if one has a meaty pair of dual mono power supplies, say in an isolated box, and 200 wpc, and the other has a weak single psu and 60 wpc, then there will clearly be considerable differences in capability. So again, all SS Class A/B amps are not equal and one justifies a higher RRP than the other.

 

[Robert]

Partially, though if one has a meaty pair of dual mono power supplies, say in an isolated box, and 200 wpc, and the other has a weak single psu and 60 wpc, then there will clearly be considerable differences in capability. So again, all SS Class A/B amps are not equal and one justifies a higher RRP than the other.

Those differences will be measurable, and you should never compare amplifiers when purely assessing sound quality where any are driven outside of specification unless you are specifically looking at how the amp performs when overdriven.

Having said that, you can walk into a shop tomorrow and buy a brand new 100wpc amplifier running form a substantial 500VA psu and a great set of specs for <£500.

 

[Greg]

True, I was straying away from measurable vs audible for a minute and making a point about purchasing decisions, but you are right regards a decent 100wpc, well powered amp for small beans. It's a solid point.

 

[Robert]

Peter Walker had the right idea when asked about amplifier sound quality.

His view was that where differences were clearly audible between good amplifier, these were due to the amplifier interface (at either end or in the middle with a pre/pwr) and the rest of the system.

Examples would be amplifier output impedance altering frequency response on certain speaker loads and the filters formed where the amplifier connects to any other component or cable.
Amplifiers using a passive pot as the pre amp are a good example. Some sources in combination with some cables will roll-off at the frequency extremes - or distortion can increase at certain volume settings where loading is highest.

To use a another example and stick with Quad, if you run their FM4 into most preamplifiers you get little low bass. It sounds odd and if you look at many of the purely subjective reviews of the FM4 it attracts comments about being bass light. Connect it to a Quad pre - or most valve pre amps - and it sounds much fuller.
The FM4 has a small coupling cap on the output and when used into the typical 10-20k input loading offered by most pre amps will roll off in the bass below 100Hz.
Quad pre amps load at 100k - so no problem.

Interface is king

 

[sideshowbob]

When I've tried blind tests, instead of being stressed or embarrassed by the outcome the process was more like, "Hmmm, as I can't reliably distinguish a 200-pound interconnect from an interconnect made of a Kit-Kat wrapper, Yale key, piece of solder and a twist tie that revelation has saved me a few squid."

Exactly. When you establish exactly what you can and can't hear, it's an entirely positive experience. I have no idea why most audiophiles are so uninterested in establishing what they really can hear.

 

[gilkinted]

A healthy Nytech from 1980 will match most modern stuff. So will a number of integrateds. I'd stack a Thorens 150/160 against most record decks up to £1500 these days, so it goes on. Maybe Class D may offer some progress, but the transistor amp hasn't come far recently.

With you all the way Steve on the Nytech. Mine used to wake up a pair of Mk 1 Kans good and proper before it blew up! Must get it fixed....

Allan

 

[Jowcol]

Exactly. When you establish exactly what you can and can't hear, it's an entirely positive experience. I have no idea why most audiophiles are so uninterested in establishing what they really can hear.

Last year I did a lot of comparisons - levels matched, instant switching with a switching box. I was very surprised with the results. It didn't matter that it wasn't a blind test, I simply couldn't hear any (or very little) difference between things. I listened through different speakers, and also through headphones. I just couldn't hear a difference at switchover. After a while I wasn't sure what I was listening to, so I became 'blind'.
I'm surprised that more people don't try this. It was a great awakening for me.

 

[tones]

Last year I did a lot of comparisons - levels matched, instant switching with a switching box. I was very surprised with the results. It didn't matter that it wasn't a blind test, I simply couldn't hear any (or very little) difference between things. I listened through different speakers, and also through headphones. I just couldn't hear a difference at switchover. After a while I wasn't sure what I was listening to, so I became 'blind'.
I'm surprised that more people don't try this. It was a great awakening for me.

This reminds me of the time when, at the invitation of the Basel Naim dealer, I was trying out a CD5 against the Meridian 588, which I regard as one of my better acquisitions (thanks, Ian!). The Naim would be much more musical, I was assured. So, in a very non-blind test, I swapped between one and the other using a switch box. And yes indeed, the Naim did sound more "musical" (or I could tell myself that it did). And then I realised that I'd messed up the switching order and that I was actually listening to the Meridian...