Flatpopely NAIM based ABX test - 24th August

[sergeauckland]

On the contrary, it's why changing the volume is important. You need to know how an amp sounds quiet and loud.

Fine, so repeat the listening tests at different volumes. If one has enough time and enough willing test subjects, one can do tests at different volumes, using different sources, different loads and so on. Just a matter of time and resources.

Doesn't remove the need for volume matching between amplifiers, as that's still essential.

S.

 

[h.g.]

The object of the test is can you hear the difference between the amps blind,

Without pinning down hearing what and how the differences are perceived it will be difficult to draw much from the results.

for the purposes of the test they will be matched to a point where they "should" be transparent (I'm doing this with Serge's very kind help) as neither will be clipping, so from the point of view that amps should sound the same, its a valid test.

What you seem to be saying here is transparently (sorry) wrong. Playing a note on a flute and a trombone at the same level does not make them sound the same.

The results of an experiment are the results of an experiment. Validity only comes into it if you claim to have measured something in particular. Pinning down what is being measured is what I am trying get explicitly stated.

 

[Robert]

Funnily enough I tried a mk1 Nait with my horn speakers not that long ago. It sounded surprisingly good. I expect I'd have found it preferable to a bigger, more complicated Naim pre-power combination under those circumstances with only a fraction of a Watt needed. They should make another shoebox sized amp of 10-12W, run it a bit richer & sell it to horny types. A whole new market sector for them. They'd do quite well!

I agree entirely Guy.

A sort of integrated 15w amp styled like a NAC72, with plug in cards for phono and a dac. Bias it to produce a couple of watts Class A.

Fly off the shelves at sub £1k.

The results of an experiment are the results of an experiment. Validity only comes into it if you claim to have measured something in particular. Pinning down what is being measured is what I am trying get explicitly stated.

I'd say that in the context of this test, the object is simply to determine how alike these amplifiers sound driving a loudspeaker which a great many people believe responds much better driven by a large, expensive Naim amplifier. We're surely looking for some pattern in the collated results ranging from no identifiable difference on the one hand, to 100% identification of each amplifier on the other. Then if we get a clear pattern in the identification, is there also a pattern for preference. What if everyone identifies the amplifiers correctly and also prefer the Nait? - that would pose many interesting questions!

That's how I see it.

It doesn't need to prove anything, it needs to inform by experience.
If everyone attending is open and receptive to the results it might influence their thinking going forward.

 

[Tenson]

Only with a Naim badge on it though

 

[sergeauckland]

Without pinning down hearing what and how the differences are perceived it will be difficult to draw much from the results.


What you seem to be saying here is transparently (sorry) wrong. Playing a note on a flute and a trombone at the same level does not make them sound the same.

The results of an experiment are the results of an experiment. Validity only comes into it if you claim to have measured something in particular. Pinning down what is being measured is what I am trying get explicitly stated.

Nothing is being "measured", it's a hearing test! It's whether a flute played on one amplifier sounds the same as a flute played on the other amplifier.

Ditto with the trombone, ditto with a whole orchestra, rock band or whatever.

I wouldn't have thought that the object of the test would be in any way controversial or difficult to understand.

Then, if the amplifiers come out different, the differences can be investigated, if that's what anyone wants to do. If they come out indistinguishable, then that too is important as it indicates that within its limitations, a NAIT is as good as a 72/125.

Everything has to be qualified, in life as in audio.

S.

 

[h.g.]

Nothing is being "measured", it's a hearing test!

Do you really mean this?

I wouldn't have thought that the object of the test would be in any way controversial or difficult to understand.

It was not called controversial or difficult. It is too imprecise to help develop the test.

Then, if the amplifiers come out different, the differences can be investigated, if that's what anyone wants to do. If they come out indistinguishable, then that too is important as it indicates that within its limitations, a NAIT is as good as a 72/125.

In an earlier post you were defining in objective terms what was required of a transparent amplifier. Where did this come from if not from a knowledge of audibility thresholds?

 

[sergeauckland]

Do you really mean this?


It was not called controversial or difficult. It is too imprecise to help develop the test.


In an earlier post you were defining in objective terms what was required of a transparent amplifier. Where did this come from if not from a knowledge of audibility thresholds?

Of course I mean it, why would I write it if I didn't!!

It seems precise enough to me, and presumably to Andrew who's hosting the tests.

Sorry, I fail to see what your third paragraph has to do with what you quoted. If the amps are indistinguishable, then there's no audible difference between them, within the limitations of the NAIT, which is mostly to do with power output, but also HF distortion which is above the 0.1% criterion. However, HF distortion is less important than MF distortion, although it can cause intermodulation audible lower down. Nevertheless, if the NAITis indistinguishable from the NAC/NAP and goes sufficiently loud into the Kans, then there's no need to use anything more powerful.

If the amps come out different, then it's possible to investigate the differences and find a reason. We haven't established whether the NAIT is transparent or not, as it does have those limitations at HF, but I would expect the NAC72/125 to be transparent going by the measurements, so if the NAIT is indistinguishable, then it too is transparent within its performance envelope.

S.

 

[flatpopely]

Without pinning down hearing what and how the differences are perceived it will be difficult to draw much from the results.


What you seem to be saying here is transparently (sorry) wrong. Playing a note on a flute and a trombone at the same level does not make them sound the same.

The results of an experiment are the results of an experiment. Validity only comes into it if you claim to have measured something in particular. Pinning down what is being measured is what I am trying get explicitly stated.

I'm not sure where this is going but I'll state the object of the test one last time. Can someone hear a difference, and therefore reliably distinguish one from the other, between a NAIT and 72/135s in the context of level matched and blind ABX testing. Either someone will be able to reliably say amp A or B is playing music throughout the test, or not actually hear a difference.

 

[Daniel Quinn]

Of course I mean it, why would I write it if I didn't!!

It seems precise enough to me, and presumably to Andrew who's hosting the tests.

Sorry, I fail to see what your third paragraph has to do with what you quoted. If the amps are indistinguishable, then there's no audible difference between them, within the limitations of the NAIT, which is mostly to do with power output, but also HF distortion which is above the 0.1% criterion. However, HF distortion is less important than MF distortion, although it can cause intermodulation audible lower down. Nevertheless, if the NAITis indistinguishable from the NAC/NAP and goes sufficiently loud into the Kans, then there's no need to use anything more powerful.

If the amps come out different, then it's possible to investigate the differences and find a reason. We haven't established whether the NAIT is transparent or not, as it does have those limitations at HF, but I would expect the NAC72/125 to be transparent going by the measurements, so if the NAIT is indistinguishable, then it too is transparent within its performance envelope.

S.

It would seem Serge is restating what was said in the James Moir "valves versus transistors" paper he referred to previously.

As the paper itself says

"ingredient x being , by definition , impossible to measure , any attempt at assessing the performance of the amplifiers by objective techniques would have been unconvincing and was therefore discarded , leaving listening tests as the only alternative.

 

[h.g.]

Of course I mean it, why would I write it if I didn't!!

Because it is clearly wrong (unless the participants keep what they hear secret!) I was asking if you had typed what you intended.

Sorry, I fail to see what your third paragraph has to do with what you quoted.

Because it is the wrong way round. If you have defined objective criteria for a transparent amplifier then you already know whether the two amplifiers are transparent by looking at existing measurements.

If the amps are indistinguishable, then there's no audible difference between them,

If you wish to say anything much about the results you may need to get to grips with what is wrong with statements like this.

A day of two ago I argued against someone claiming that listening tests like this were difficult to perform in an acceptable scientific manner. For whatever that may be worth to audiophiles. Perhaps I should stop sticking my oar in and observe.

 

[sergeauckland]

Because it is clearly wrong (unless the participants keep what they hear secret!) I was asking if you had typed what you intended.

Of course participants have to keep what they hear to themselves. Ideally, each participant would be alone, and the tests repeated for each new participant. Clearly, this would take a very long time, so the panel have to listen at the same time. However, there must be NO conferring or commenting until the tests are over as otherwise there's the possibility of influence. I would have thought that was as obvious as the need for level matching.

S.

 

[mmaatt]

Are the listeners going to leave the room while you change the cables? If not you can easily tell which amps are which by the number/delay of switch on switch off thumps.

mat

 

[sergeauckland]

Are the listeners going to leave the room while you change the cables? If not you can easily tell which amps are which by the number/delay of switch on switch off thumps.

mat

If a Naim amplifier can tolerate an open-circuit output, then I would just hot-swap the cables without switching the amplifiers off.

S

 

[Brian]

Of course - in the same way that I am free to comment.

My comment was not aimed at you specifically Brian, or at anyone in particular. However, if anyone is unhappy with the equipment, or procedure, Andrew is proposing why should they not set up their own event?

Yeah, that's fair enough. Sorry I dived in.

I've never heard Kans with 135's, in fact I've only heard Kans with my own 110 I had at the time and I found them so limiting I'm not sure anything can improve them. That's why I sold them. Could have been the room, of course. I know I could be well off the mark here and I also know there are many others with far more exposure to Kans with alternative amplifiers than I have, so I hope they're ideal.

I'm really interested in how this turns out. With the effort Andrew will have to put into it, it will be a shame to give some individuals a reason to disregard the outcome based on some flimsy excuse. Reading between the lines a few are already building up to that imo. The Nait isn't transparent, etc etc.

 

[Brian]

brian why don't you go in tensons place....

darryl,

Any specific reason why you made that suggestion?

 

[Paul3]

I am very interested in attending, if there is room available. ( I am only small )

I have Kans, used to have a Nait and 32.5/Hi/250, so am very interested.

Regards
Paul

 

[YNWOAN]

Andrew and I have previous experience of these types of hi-fi shindig . Unfortunately, the one thing that can be guaranteed is that no matter how much care he takes to address all concerns someone will still not be happy. Such is the nature of the world. If a bit of fun can be had and ones experience furthered, well then that's good enough for me.

 

[Robert]

If a Naim amplifier can tolerate an open-circuit output, then I would just hot-swap the cables without switching the amplifiers off.

S

It can.

 

[flatpopely]

I am very interested in attending, if there is room available. ( I am only small )

I have Kans, used to have a Nait and 32.5/Hi/250, so am very interested.

Regards
Paul

Hi Paul, I'll add you to the list.

Please PM me your email, thanks.

 

[flatpopely]

It can.

Yup, done it loads before.