Are all amps being built wrong?

Erik-just for clarity - I was not disagreeing with you, just adding and referencing what you said rather than blather on and being repetitive :-)

My answer to the original posed question is "not at all, not even close"

I think Eric contributed some good stuff above.


As am amp designer, i think they ought to be voltage sources, with low output impedance.  Now, for the record mine are not zero, because i don't like to employ global control (feedback) loops nor expose those loops to external elements that create unknown stability issues.  But we are talking small fractions of an ohm.

I realize that a higher output impedance may result in a warmer 'bloom", but that's a coloration, whether you like it or not.


A current source would likely result in very distorted sound. Also note that the impedance of a speaker changes on many dimensions - with frequency, with excursion of the electromagnets, with volume, ....so why would we want to make the gain impedance dependent?
G

re: Vandersteen's being hard to drive.
I had 2Cs and then 2Cis and 2Ces.  They were the easiest, least fussy speakers to drive i ever owned.  Drive them with a 20 W NAD 3020 that could NOT drive Spica TC or SC-50s.  Drove them with a pair of tiny Lux tube amps.  They are very resistive, basically 8 ohms, and modest sensitivity (87 dB???).


Look at the impedance curves for heaven's sake.  Do they like good amps? Sure.  Do they like highly capable, high current amps? Sure, i guess. Do they need them to make music? Nope.

Mainly because speakers are designed to be driven by a low impedance voltage source.

Aside from what i already wrote, here's also the practical issue.  A low impedance, hgih current amp will drive anything.  Others might (might) sing with speaker A and suck with speaker B. You know, like lots of high end :-)
I'm always fascinated by this. I cam plug my amp into about anything and it will work very well and sound very good. Will it produce some synergistic, euphonic magic effect? Nope.

This isn’t quite correct, just so you know. Try putting your amp on a Sound Lab ESL sometime.

One of my business partners at the time had West Sound Lab monsters and used, of course, my amps. Sounded terrific (all speakers are, of course, to someone’s taste). no issues whatsoever. Just sayin’

Edit, after some coffee, do remember back (oh, 300 posts ago, i get it :-)) that my designs are not zero output impedance. Since they do not use global feedback, there is always *some* meaningful output impedance, but also, pretty much zero chance of instability.  Both often issues with large 'stats.

I also did not measure their spectral output, just listened.  using my favorite measurement aid of the time, single malt scotch.

Now would someone prefer quickie's or yours? maybe.

oops, very late to reply to @atmasphere

Output Z of the amps, depending on model is around .1 - .2 (rarely this high) ohms. Small but very clearly not zero.
And yes the stability is a very big plus.
Of course it means bias stability demands attention, but i solved that decades ago.