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
@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.
I too have the Orchid DAC and have tried several brand tubes in it.  Each having it's own sound signature.  Vibration isolation, cables and power conditioning would probably have a greater effect than a different amp of similar power output using all the same existing other components.
If I really had $5000 dollars to spend and being primarily a digital listener replacing the Orchid would be the biggest improvement for the dollar.
@cd318

@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?

I am following this thread with some interest.  It seems to me @jjss49 just did.  I am not sure if it is groundbreaking in any sense, but I think he just stated his findings from his comparison in his posting.
@whipsaw,

Perhaps I should have been clearer in stating that no one has been able to consistently identify sonic differences between 2 level matched solid state (sand) amps. 

With valve amps all bets are off, though even there it's been noticed that better measuring valve amps tend to sonically converge, not diverge, with their solid state counterparts. A straight wire with gain as Quad's Peter Walker once said. Didn't he also claim that he didn't need to listen to his amps? The measurements alone told him everything he needed to know.

And then there was the infamous Bob Carver Stereophile challenge which surely anyone with any amplifier interest should be familiar with.

https://www.bobcarvercorp.com/carver-challenge



@troidelover1499,

Fair enough, but don't you think such a groundbreaking discovery is worthy of a public repitition?

Just imagine how many magazine editors and reviewers would come racing to plant laurels around the head of this much welcomed harbinger of glad tidings?

Of course no designer of any digital product, cable or amplifier has ever claimed or even attempted to demonstrate the sonic superiority of their product, let alone subject it to a blind listening test.

I wonder why?

So why not go ahead, and make their day if you can?  I think we'd all be curious as to what exactly these so called claimed differences actually amount to.
 A straight wire with gain as Quad's Peter Walker once said. Didn't he also claim that he didn't need to listen to his amps? The measurements alone told him everything he needed to know.
This is a view that most amplifier designers disagree with, not to mention the vast majority of audiophiles. 

Measurements do not tell the whole story.