Purifi Class D

[Iving]

... not to mention 78s (https://recordcollectormag.com/articles/78) inc. Blues history some of which is known to be lost ...

 

... bootlegs ...

 

... Universal fire or other foreseeable perils to original recordings (such that any or any good digital masters can no longer be created) ...

 

... commercial forces affecting the future availability of acceptable material cf. MQA ...

 

Plus huge variability in quality of digital mastering for same source material e.g. Elvis stuff and a lot of obscure 50s Rockabilly. Some issues have mojo. Some are diabolical - usually an attempt to make something sound appealing to casual listeners cf. Loudness problem.

 

This apart from the argument that you can build a musically satisfying analogue playback system on a budget - whereas making digits musically inoffensive demands money, blood, sweat and tears.

[Iving]

3 hours ago, barrows said:

OK, I agree that if one listens to a significant amount of music which is not available in a decent digital version an analog rig is needed.  To be sure, I have a certain affection for vinyl discs, and have been buying them again (although I have currently have no analog 'table or phono stage, perhaps in retirement I will add such, otherwise the discs are collectables). But looking at it from the other side: there is much more music these days which is very good, and is often only available in digital versions, and often when vinyl is available the pressings are questionable.  Which means that if one loves music, one is going to need a well sorted out digital playback system, regardless of how much money, blood, sweat, and tears is involved.  Actually, a good digital set up is not too hard to achieve, or too expensive in audiophile terms (Holo Audio Spring as a start, oversampling via HQPlayer) these days.  Doing so does not require a dCS or MSB investment level.

But to suggest that one does not have an adequate reference to evaluate amplifiers unless they are spinning plastic discs is just in error.

 

Well I admit I keep forgetting that, for the most part, my music taste coincides with the vinyl era (say '54 to '84) ...

 

... so much so I wouldn't remark publicly regards optimal systems for playing back contemporary digital recordings.

 

The convenience argument in favour of digits, notwithstanding, is massive. Not just sitting in chair with remote, but ease of discovery. And I don't (won't!) download or stream.

 

I could never afford to discover and enjoy my favourite music via original format/vinyl - and I am on online trader with a lot of records - and fortunately CDs - passing through my hands.

 

I'm proud of my digital system, even though building it to a level where it doesn't shriek at me has been far, far more costly and painful than I imagined.

 

If I started digital again - on a budget - I still wouldn't stream or download. I wouldn't oversample as a strategy (I do upsample x 4 in fb2k/Sox but more as an optimising tweak). I would start with far more co-operative speakers than I have - and set my sights and expectations much lower.

 

The way I read the thread earlier, Rexp was just having fun grinding his vinyl axe. It's difficult not to join in.

 

I will (hopefully) be in the market for better power amps before long. I'm almost certain I want to vertically bi-amp with Linnn Klimax Twins. I confess I'm following a mindset (as well as the advice of the manufacturer of my Snell Type A III). I don't mind. Music is personal. To compound my metaphors, you gotta float your boat and there are many ways to skin the cat.

 

Do all roads lead to Rome nevertheless? Is there some system (live music aside) that might render all of us agog? I think probably not.

[Iving]

7 minutes ago, barrows said:

I would propose, that most folks who prefer vinyl playback, tend to do so because of, rather than in spite of vinyl's rather significant shortcomings/artifacts.

 

one need not spend 5 figures for an excellent DAC).

 

All of the improvements I've achieved in my digital system have been about taming the banshee. Then adding body. But mainly taming the banshee. 

 

I don't think I'm chasing a vinyl phantom/template. I'm not into valves or anything like that.

 

The improvements I do make are satisfying of themselves. Which means that digits can beguile my ears.

 

I have a good DAC. I think the digits problem is mostly to do with electrical noise tbh. Jitter - that too I guess!

[Iving]

6 minutes ago, Jud said:

 

Need to be careful about generalizing, though.  I prefer vinyl playback *for specific recordings*.  I've never yet heard a digital mastering that quite captures all the magic of Pinball Wizard from my 50+ year old LP of The Who's Tommy.  Same with a couple of tracks from the LP of Steely Dan's Gaucho.  (The latter case in particular seems strange to me - I may just not have run across the right digital mastering yet.)  And there are many of my old LPs that aren't carried on the streaming service I favor, and that I'm not going to go to the trouble and expense of obtaining new digital versions for even if they exist.  So there's plenty of use for my turntable yet.

 

However, for most recordings I'll take digital.

 

Ooh I wish you hadn't said the last bit! But a Like anyway ;-)

[Iving]

3 hours ago, Rexp said:

older analogue recordings from the likes of John Coltrane etc.

 

3 hours ago, John Hughes said:

For sure a first pressing of say Miles Davis from 1960 in great condition will probably blow away any digital version, because the master tapes today have degraded significantly (and the tape player is probably not ideal or adjusted/tuned correctly either in most case). 

 

I've heard more valve era records than I could afford to buy as I have traded commercially for some years. It's a particular kind of experience playing these discs inc. DECCA wb sxl etc even on mediocre decks (the ones I use for cleaning records - you can easily hear the difference). I can't say I've done systematic comparisons with digital equivalents. But many congruent digital non-classical issues sound dire - Loudness if nothing else. So bad that it's easy to attribute to the master not the digital playback system. What I'm really wanting to say tho' is that no matter my experiences - the market has an opinion of its own. To acquire a respectable collection of these records now, and buy the deck fitting for their enjoyment,  you'd have to be pretty seriously wealthy. Probably there's also a longevity argument in play for long term investment. 

[Iving]

2 minutes ago, John Hughes said:

Yes, I have hundreds of irreplaceable records pressed in that era.  Ribbon mics, judicious use of tube compressors, tube recording gear, and engineers that actually understood music :)  Those are the gems, and too few people have heard what analog performance was capable of and what those records can do. But that's the past.   RCA original Dynagroove, Mercury Living Presence, CBS Six Eyes :) Sigh. 

 

But exactly! This is part of the argument for an analogue front end. Playing them now is most certainly not the past. It's the present. And future!

[Iving]

3 hours ago, John Hughes said:

I've had top end vinyl systems (5 figures and up

 

I have also done a fair amount of ADC of tape masters and vinyl

 

I have some high resolution digital conversions I made of2nd and 3rd generation master tapes and my favorite vinyl taken when my analog rig was at peak performance.  I have been comparing them with high resolution digital versions that I have for the same albums.  With my carefully built and tuned digital rig, I find I prefer the high resolution remasters to the vinyl rips I have.  The qualities of the vinyl may be a bit more open in the midrange, but the high rez remasters are clearly superior in bass and treble and detail.

 

With respect, a Linn Klimax LP12 starts at twice the point that 5 figures begins! More to the point I've never understood ADC of vinyl records for any purpose.

[Iving]

3 hours ago, John Hughes said:

I simply don't understand the clamor for modern vinyl when most is not analog

 

Absolutely agree. It's completely barmy.

[Iving]

3 hours ago, John Hughes said:

just as physical isolation is critical to great analog, electrical isolation and filtration is required to get the best out of digital.

 

Absolutely agree in my experience

[Iving]

19 minutes ago, barrows said:

So here, what you are actually saying is that you like the sound of lots of distortion/noise added to the music: tube gear of that era certainly added lots of distortion, same with ribbon mics, etc.  There is nothing wrong with that per se, but it is not actually high fidelity to the music.  And yes, I have heard many vinyl records from the late 50s and 60s.  In fact it is very likely that a clever digital recording engineer, today, could emulate that sound for you in their recordings using DSP.

 

To me this may be true but it is a red herring.

 

Everything is an eruption of history. Things are of their time. To the sensitive person, there is nothing like listening to say pre-War Jazz or Blues on shellac.

 

Same for valve era vinyl.

 

Music, as we know, is highly nostalgic and biographically significant. I may prefer to listen to a hit single played back as I did when I first heard it.

 

Even if a valve era recording is more distorted than one made in the digital age, it may still sound better on a record deck for the many reasons covered in the last p. or 2 of this Thread.

 

Personally I would consider DSP last resort - if at all.

[Iving]

13 minutes ago, mocenigo said:

If "Typical blind A-B or ABX tests are worthless" then all listening tests are worthless.

 

Confirmation bias is a beast that lives in the subconscious

 

Hi Roberto,

 

Forgive me butting in - I don't have much to say about Class D - just a brief remark on what you are saying here.

 

As I explained on ASR only recently (harking to ostensible "reverse" as an instance), Expectation Bias is a subjective phenomenon arising out of Cognitive Dissonance. The latter is psychological conflict which arises because of the reward anticipated after an Instrumental/Operant decision. Beliefs or understandings are shifted post hoc to fit the decision. The driver of all conditioning is the reward. Stereotypically we audiophiles think of cables and the like. But these mental processes happen in all domains of human existence. How much more beautiful a person becomes once we have decided upon marriage. The "reverse" type you envisage is perfectly plausible, but really would be an instance where the belief or understanding "no difference" was generated to justify a less obvious reward. Examples might be the money remaining in your bank account the result of not buying something. Or being right (an unfortunately pervasive human disposition) on an audio forum.

 

Now I can quite believe that Reward/Reinforcement hunger resides in "the subconscious" (whatever that may be - but we don't really need to get all Freudian) and, so, I can agree that "Confirmation bias is a beast that lives in the subconscious".

 

All I want to say here is that "Typical blind A-B or ABX tests" rely on conscious cognitive/mental processing. In fact, listening skills training - very deliberate focus on this and that/tells, and repeated practice - can result in better measurable performance in ABX tests. The point is - that if Biases emanate from the "subconscious", then listening tests which are sensitive to subconscious processing are necessary in order to reach your conclusion, If "Typical blind A-B or ABX tests are worthless" then all listening tests are worthless. What's more - there would have to be parity of results between conscious and subconscious-sensitive tests in order for your assertion to be valid.

 

Such subconscious tests don't exist as a matter of formality. But in theory they could. You cannot begin this kind of discussion on ASR. As @PYP hilariously pointed out recently, most ASR members seem to have IBS. ASR is a blue collar socio-cultural movement with a chief honcho who must be revered - and a mission to convert whom they regard as the foolish. ASR is much more "Scientism" than "Science". If it were a political movement we should fear for our lives.

 

Not looking for a lengthy debate or argument. Just food for thought. I don't have a model for subconscious-sensitive listening tests - nor the inclination to derive and publish any. Once maybe. Not now. Thank you

[Iving]

2 hours ago, Jud said:

The problem, scientifically, is that no matter the source, the listeners really don’t have the ability to do blind ABX tests for anything that isn’t readily apparent in about 4 seconds, unless they are trained or the “right” answer is suggested.

 

I did an informal A/B test here once with a few dozen participants, regarding whether people could hear a difference between two quite different acoustic guitars given two second vs. 30 second samples (one a classic Martin, the other a 1930s Epiphone with a much smaller sound chamber and a couple of f holes). Those hearing the 30 second sample were able to discriminate better, with a p value of .06.  (In other words, one would have expected the same result by chance only 6% of the time.)

 

As you’ve said, one would hardly expect gross effects given the current state of electronics, so what’s left are relative subtleties. But some of these subtleties may be important to musical enjoyment. I doubt, based on the scientific work of the past decades, that ABX testing is a very good tool for teasing out any differences in equipment that may still exist.

 

Hi Jud,

 

I spent a goodly while ... keen to understand this post as a coherent whole.

 

1. I get the point about echoic memory <4 secs. If empirically true, then blind test performance will be reduced for stimuli longer than 4 secs - as "interference" from the part of the stimulus >4 secs. will exacerbate what we might already expect from deleterious "forgetting" what is in excess of 4 secs.. Would you agree with this. In other words, keeping stimuli to <4 secs. is something we could do to enhance sensitivity in tests.

 

2. I tried and failed to get my head round the Design of your (GW/DR) guitar test. After making notes to myself I found your original 2015 thread. Looked like a great deal of social fun, but may I say that I agree with whomsoever intimated that the discrimination was easy. Not really a blind test as such. "Scientifically" may I say that the Design had no hope of isolating any independent variable such that you could say today "Those hearing the 30 second sample were able to discriminate better, with a p value of .06.  In any event, I find it impossible to map such an assertion to what you are saying about 4 sec. echoic memory. No doubt I lack enough detail or haven't drunk enough coffee.

 

3. Regards "electronics" (cf. speakers! and etc) I agree very much that "what’s left are relative subtleties. But some of these subtleties may be important to musical enjoyment". I don't feel strongly about you saying, "I doubt, based on the scientific work of the past decades, that ABX testing is a very good tool for teasing out any differences in equipment that may still exist." [something manufacturers could pursue, but don't pursue, and for understandable reasons, both good and bad] but imo I do think that testing could yet help us reconcile ourselves (as enthusiasts for enjoyment of music which we have in common) when it comes to the Subjectivist-Objectivist divide. Probably - there is only one "truth" - and we fail to find the common ground germane. I have had ideas in the past - some only vaguely formed - and began to formulate more (including ref. to "subconscious") provoked in the nicest way by @mocenigo. Trouble is - it takes a lot of time, and so on, and also goodwill amongst us to make mutual progress. That is what I find saddest about Forum participation.

 

Fortunately there is much joy to be had too! Wish I'd been around for your 2015 thread. I have been a member here since 2015. Perhaps - being a humble newbie - I ignored it!

[Iving]

12 hours ago, Jud said:

See https://en.wikipedia.org/wiki/New_Coke .  In a blind A/B test, the sweeter drink won.  Yet when a sweeter drink was marketed to consumers, it bombed. Think about why this happened - I believe it has implications for audio.

 

Well - evidently people buy stuff for reasons other than what they may "objectively" prefer [many drinkers reacted angrily to finding they had chosen a brand other than their favorite]. I say "objectively" in inverted commas because a (lab) blind taste test may demonstrate that "all things equal" A is preferred over B or C - but, evidently, things are not otherwise equal. In the case of cola drinks people are swayed by brand - i.e. what they understand. Possible in Hi-Fi too I guess. "I'm a dCS guy." "Can't hear the music unless it's piped MQA." What are the factors that promote brand over "objective" preference? People may want to "belong" (In Crowd) or feel superior (I only drink Coke.) They may simply seek nostalgia - and why not - just love the shape of that Coke bottle - I am right back on the beach listening to Mungo Jerry at Chart position #1. Not all people of course! There are individual differences - shades of effect - iow "Personality". Main dimension something to do with suggestibility. Now suggestibility doesn't necessarily mean that Subjective experiences aren't "real". Of course they are! If someone buys a $/£/€10k cable and believes they're getting their money's worth, that person may be a suggestible oaf - but they have - indeed - gotten value for their money. Their Subjective experience is no less real than yours or my preference for Buddy Holly or Britney Spears. Of greater interest is whether leverage can be obtained on those Subjective experiences - they are rendered elastic/plastic - such as to conform with what "objective" data determine we should prefer. That is the mission of ASR. And it is a mission. The ASR onus of proof is always on the golden-eared audiophool whom ASR people are "desperate" to convert. People polarise in order to be right. It is the cause of all human conflict - the reverse of "Live And Let Live". "Women are better than men." "Men are better than women." OK a dated example - but for illustration. "ABX tests are the only source of listening objectivity." "Ultimately I trust my ears." People cleaving to these polar positions possess a reality of sorts - if they truly believe what they say; however, by all accounts progression leads us to understand that men and women are merely different regards biological sex. Actually morally equal? I say with question mark because dinosaurs exist. Many things can be true at once. But polar positions cannot co-exist as "truth" at once. This is what I mean by, Probably - there is only one "truth". If Subjectivists and Objectivists (and people in between) are sufficiently open-minded, that "truth" can be sought co-operatively. It can be hunted iteratively. The Scientific Method - as we know it - may not take us the whole way. But it is a start - and it cannot be outranked by ignorance or prejudice en route. Very often we can get nearer to a better understanding of something by ruling out a lot of ideas we have once taken for granted.

 

12 hours ago, Jud said:

Left-handers often hear differently than right-handers, see http://deutsch.ucsd.edu/psychology/pages.php?i=208 .  But fascinatingly, some left-handers, apparently as a result of experiencing our right-handed world, hear as right-handers do. I believe this also has implications for audio.

 

The Cambiata illusion is fascinating - but one of many examples of brain at work. There is no-one on the planet who understands (to any degree of completeness) how the human brain works. It is full of mysteries. Science would have nothing to discover without mysteries. I have already said that Science, as we know it, may not go all the way in facilitating humans to understanding "everything" - and even that notion - that humans have the capacity to understand "everything" (including themselves) is highly moot as far as I am concerned. Science as religion, aka Scientism, is just as phoolish as the $/£/€10k cable purchase. So I think the greatest asset we can develop as audiophiles interested in these things is open-mindedness. The second prerogative is social nicety aka "courtesy"; at least - the motivation to find common ground instead of seeking to be "right" which - it seems to me - is no different to drinking Coke when you "actually" prefer something sweeter.

 

You asked me to think about your links, which I have done. Twice you said, "I believe ... has implications for audio." Please don't be reticent. What are the implications as you see them?

[Iving]

5 hours ago, Jud said:

The qualities that people prefer in a blind test, a sort of “quick hit” to our sensory perceptions, may not be those they prefer in situations where they are able to partake of the product at their leisure.

 

Yes - I can think of reasons why the lab cannot recreate conditions that could aid discrimination at home. Context is a big deal in associative learning.

 

5 hours ago, Jud said:

In audio, we know that greater loudness will be preferred; if loudness is carefully equalized, are there other qualities that are preferred in rapid listening tests, but not over the longer term?

 

Well ABX gurus insist (correctly) on equalising loudness across conditions. Your remark suggests that people may succeed in the lab because of factors that do not apply to discrimination at home - the converse of above.

 

5 hours ago, Jud said:

humans are terrific at pattern matching ... New Coke didn’t match the pattern built up over years of “having a Coke.” It didn’t taste “right.” The same with audio. We build up preferences over years and then recognize when something doesn’t fit the familiar pattern. We can perceive this as an improvement, or perhaps as sounding worse. But we should recognize that long familiarity does ingrain patterns that sound “right” to us.

 

Totally see this. Alludes to capacity of brain to perform all sorts of somersaults. Question is whether ABX etc insensitive to pattern matching wrt being able to "tell the difference". Is it possible to develop "pattern-matching" tests which reach the parts ABX cannot.

 

5 hours ago, Jud said:

Our brains are so good at matching patterns they sometimes create patterns that don’t exist.

 

For sure. Our brains make up all kinds of sh*t. Perhaps in some ways we enjoy music more because of it. Another reason for the IBS crowd to leave everyone else be. What might brain inventiveness tell us about "audio reality" either way. Does it matter (to audiophiles).

[Iving]

18 minutes ago, PYP said:

could substitute "humans" for "audiophiles" and broaden your excellent advice.  There seems to be a sudden fondness on our little planet for hardening opinions as a show of strength when it in fact demonstrates fear.   

 

So agree. :-)