Is there a point of diminished returns with amps and Harbeth 30.1s?


I’m currently using Herron M1As with my 30.1s and I’ve upgraded the rest of my system (Aries/Fatboy/SUT/DL103r and Lamm pre and phono) and each upgrade has been VERY satisfying. So is it going to be worth spending $5000 or so on the used market to upgrade the Herrons? Any thoughts as to whether I’ve reached the apex of amp/speaker performace for the M30.1s?
dhcod

I agree that this is potentially problematic, but to be fair, such tests are not about preferences, but differences. In other words, can the listener simply and consistently distinguish between components, irrespective of which they may prefer.


@whipsaw is exactly correct

a-b tests, done correctly, first establishes that a difference can be reliably and consistently be heard, then comes an assessment of the nature of differences, and then, perhaps, a judgement about preference might be made ... one step at a time

a-b tests don’t replace longer term listening in fully assessing gear and their sonic attributes -- but is an important tool in the tool kit, so to speak

there are some who profess that all amps, all cables, all connections, sound the same... thus a proper a-b test is needed to dispel (or confirm) these notions
@whipsaw,

As far as I know there has not been a single example of a blind listening test where differences between cables, digital sources or even amplifiers were identified.

Even in the best case scenario, subjectivists et al might want to acknowledge this rather sobering fact.

Not even one case??

Perhaps there are some good reasons why Toole, Olive and co only bothered blind testing loudspeakers at the National Research Council (NRC) of Canada in Ottawa, Ontario?
As far as I know there has not been a single example of a blind listening test where differences between cables, digital sources or even amplifiers were identified.


@cd318
can evidently type... but he can’t read... amazing how that can be... usually even rudimentary literacy works in both input and output modes

i just cited in a my earlier post that i did a rigorous a-b-c test of power amps on super 5’s, and for myself, dispelled this kool-aid/nonsense

seriously...🙈🙉🙊
@jjss49 ,

I was referring of course to published tests, ones that could be verified.

If you could successfully repeat your experiment I'm sure there would be an awful lot of interested parties willing to assist you in your groundbreaking demonstration.

No end of reviewers, magazines, websites would be very pleased to have just a morsel of evidence to back up their printed proclamations regarding sonic differences of amplifiers.

Heck, they might even start conducting their own.

Why not consider publicly sharing your groundbreaking research for others benefit? 
@cd318

The problem with your perspective on this issue, one that, in my view, is shared by a good percentage of the HUG members, is that it is too rigid.

Few would argue that anecdotal experiences are as broadly compelling as carefully executed, published studies, but to essentially lump them all together, and so easily dismiss them, reflects a rather closed mind.

To use just one of many examples of why I believe that to be the case, consider a poster on the Audio Science Review known as "DonH56". He is described as a "Major Contributor" and "Technical Expert", and his background, as displayed on his profile, is:

Design and now validation electrical engineer, focused on high-speed (GHz+) analog and mixed-signal circuits. Did a fair amount of audio design in my youth, including tube and SS preamps and power amps, and a servo-controlled subwoofer back when they were new and few.

I was principal trumpet of the Pikes Peak Philharmonic orchestra, have played in a few jazz and big bands around the area, led the trumpets for the Tri-Lakes Music Association for many years, done a few "pro" gigs, and sometimes play at church.

So, given that the ASR is likely the most broadly skeptical, and science/test-based audio forum in the world, it is safe to say that this member is, to put it mildly, no fool.

I noticed one of his posts on a thread related to the very topic that we are discussing, and have excerpted some bits, and linked to it below.

My assertion is usually weasel-worded as "most SS amps operated within their linear region driving most typical speakers will sound the same". Lots of ambiguity because I have not listened to, let alone measured, a large sample of amps connected to a similarly large sample of speakers any time recently. Treat all that follows as opinion.

***

I suspect few of us would have a problem distinguishing a SS amp from a tube amp. The differences, measured and heard, are large enough to be clearly audible on most speakers.

***

The gain structure and noise floor of the amp is in play as well; one of things I (many people) found years ago was, in blind testing, an amp with a higher noise floor was readily distinguished from another amp. We did a test with two tape (yes, 1/2" tape at that time) loops playing the same music selections using a couple of big SS amps (have forgotten which, Krell, Threshold, and Levinson were in the store at that time, among others). The speakers I’ve forgotten but I think were either Magnepan MG-20’s or B&W 801’s ca. 1982’ish. We might have run with both speakers, too long for me to recall. We inserted a 2 s silence between the selections on one tape, and went straight from one selection to another on the other. The selections were a mix of music but did not have very quiet (silent) passages. Gain matched the channels, natch. With the 2 s gaps, people easily picked out the "noisier" amp, and commented how it "filled in" gaps between piano notes, drum strikes, and such. Without the gaps, nobody was able to tell the two amps apart. IIRC the noisier one was class A but had fairly low SNR, like 80 - 90 dB unweighted, whilst the other amp was something like 100+ dB.
https://www.audiosciencereview.com/forum/index.php?threads/double-blind-tests-did-show-amplifiers-to...

Note how he reports that the difference between how subjects were able to distinguish between the two amps with two seconds of silence between the selections, but not without. That alone provides a potentially important insight into why the results of "classic" blind-tests may not necessarily tell the whole story.

This person is an electrical engineer who has designed and built amplifiers, and a professional musician to top it off. Yet while he is broadly in agreement with those who claim that amps sound the same, his experiences have led him to the conclusion that it is not always the case.

Not so easily dismissed, in my view, and there are many other, similar examples of compelling anecdotes to be found.