Can SMPS based preamps/amps sound organic ?

FWIW, my DEQX HDP-5 preamp/processor, which is their top-of-the-line model, uses a switching power supply. Their somewhat less expensive previous top-of-the-line model, the HDP-4, uses a linear supply.

I suspect that a factor in their decision to make that change may have been a need for additional internal real estate, because the newer model incorporates a touchscreen and some other functions that were not provided in the HDP-4. But in any event I have been very pleased with the unit’s transparency, absence of coloration, and total absence of noise at any volume setting.

Charles, regarding your question my guess is that contributing factors to the continued bias toward linear supplies that seems to be evident among many designers include their own familiarity with the use of those supplies, and perhaps also an expectation that many potential customers would be similarly biased.

Best regards,
-- Al

Charles, yes, as I’ve said in a number of past threads my belief is that specs and measurements can often be useful, but primarily because they can often make it possible to **rule out** components from consideration. In some cases by raising doubt (or worse) as to how suitable a component may be for use in conjunction with other system components. In some cases by raising doubt (or worse) with respect to how suitable a component may be with respect to user requirements (such as a desired maximum volume capability, for example). And in some cases because a spec or measurement that is **too** good (such as extremely low total harmonic distortion, for example) may create suspicion that something else has been compromised to achieve that (such as heavy-handed application of feedback).

But I’m certainly with you in considering sonics to be THE selection criterion once the list of candidates has been narrowed down as much as possible on the basis of specs and measurements, as well as on the basis of cost, physical configuration, manufacturer reputation for support, and other such factors.

Also, as you may have observed over the years, with a few exceptions I usually tend to avoid participating in threads involving ecclesiastical controversies about the superiority or inferiority of one design approach vs. another. Such as might arise with respect to switching vs. linear power supplies. The reason being, as I know you would agree, that what usually matters most is how well a chosen design approach is implemented, not which approach is chosen.

Best regards,
-- Al

Interesting references. FYI, I tried to find Mr. Sanders’ patent or patent application for his regulated power supply design, which would have provided more information about it.  But extensive searching at the Patent Office website (uspto.gov), using numerous search terms that seemed likely to be relevant, turned up nothing. So unless I somehow missed it the application has apparently not yet been submitted.

Best regards,
-- Al

Thanks, Bombaywalla.

Let me first make clear that I was not implying anything negative about Mr. Sanders or his design. I was just reporting that I looked for the patent or patent application, in the hope of finding further detail about the design, and couldn’t find it.

The mention of "patent pending" appears in numerous articles on the web, as well as in Mr. Sanders white paper that you referenced earlier. Presumably all of those statements were based on inputs he provided, at the times the articles were written.

Regarding the unrelated patent application you linked to just above, which was filed in 2003, I can find no indication that a corresponding patent was ever issued.

I suppose there are all kinds of possible explanations for these non-findings, ranging from issues with the Patent Office’s website and/or its search functions to decisions he may have eventually made to not pursue the applications, for whatever reasons.

Best regards,
-- Al

Thanks, Bombaywalla. Yes, a delay of a few years between application and grant would certainly be understandable. My reference to 2003 for the "encapsulated composite electrostatic loudspeaker stator" application you had found was correct, however. As can be seen on the left side of the page, a short way down from the top: "Filed: October 30, 2003."

Best regards,
-- Al