No , it has no relation to distortion
That's unlikely...
All amps have distortion- its literally the sonic signature of any amp!
Please watch the recent Romy the cat video (I recommemend it to all members) about 6 month (3600 hours) time and effort for designing SET amplifier Horn speaker. If you get lush puffy sound from SET the problem is not SET. The problem is the non matching impedance.
Huh? You're always going to get lush sound from any SET owing entirely to its distortion signature.
Peter, this problem comes from marketing.
Manufactures tune the camera zoom for maximum sale not better sound and introduce us many reasons that X is better than Y, actually X is not better than Y.
FWIW Dept.: we don't sell a direct drive turntable. This assertion as it relates to me is false.
.Ralph is wrong that 3rd in isolation sweetens things a bit.
I am correct in that. Any properly functioning reel to reel tape machine produces a 3rd harmonic and I don't see anyone including you that objects to its distortion signature (not that I've not mentioned this to you before...). Recording studios use reel to reel as an effect these days for precisely this reason. You might want to drop this notion as it is fictitious. Otherwise you're flying the face of all recordings made up until sometime in the very late 1970s when the first 3M digital machine first appeared here in the Twin Cities.
I and a few others have asked: what real progress has audio achieved since the 1950s-1960s? Speaker footprint and width has gone down while prices have soared. Sound and the listening experience, that is the question for me.
Cartridges and tonearms are vastly improved- able to handle greater modulation in the grooves without mistracking. Testing and lab reports of the 1960s as any reference as to what the LP is capable of aren't really accurate on this account. Bandwidth is wider too- by the mid 1970s most cartridges were capable of 30KHz and the better ones past 40KHz. Cartridges of the 50s didn't have a prayer of this and those of the 60s struggled at best.
Technics developed the first DD turntable, the SL1100, in the early 1970s. They have led the way in direct drive and while belt drive did quite well against other direct drive brands, never really was up to beating the higher end Technics. Of course Technics has widened that gap in the last 5-6 years.
Tuntables have improved a lot compared to the fare of the 1950s and 60s, just in terms of speed stability and vibration control, whether an idler drive, belt drive or DD. While the Garrad 301, Thorens 124, Empire 208 and a few others are nice machines, they are a
lot nicer when given a proper plinth and the like, courtesy of a few decades of experience.
There is actually materials science that has produced better platter pads too, something that no-one thought about the 1950s, 60s, or 70s. We now know that controlling resonance in the vinyl as its being played is essential; the first step of a 1,000 mile journey.
We have seen far better speaker cables too. If you're running a single-ended audio path, RCA cables have gotten better since Robert Fulton founded in the high end cable industry in the late 1970s.
Semiconductors are vastly improved. Opamps were invented in the 1950s and first marketed by Philbrick Research (and were all-tube). Solid state opamps came along in the 1960s and by the end of the 1960s made musical synthesizers practical as well as a variety of effects pedals to the music industry. By the mid 1970s they were common in solid state stuff, but during this time they really weren't 'high end'. That's changed now- you can get really good opamps for $3-$4.00 that are excellent in every way. If you don't demand too much gain of them (20dB being a very practical limit) they are extremely neutral with no harshness at all. Of course there are better discrete semiconductors too which has made class D practical and a real force to be dealt with in high end audio- to the point that there are plenty of people finally retiring their SETs for class D amps and not looking back.
Loudspeakers have gotten better too. Computer optimization of horn tapers has resulted in lower distortion horns, and materials science has led to diaphragms that lack many of the breakups seen in vintage designs. So speakers have gotten more revealing and smoother at the same time. In addition, the way standing waves affect bass in a room is better understood and so subwoofer solutions to break up standing waves (and powered subs themselves) are a big step forward.
Amps, even SETs, are now lower distortion which translates directly to greater transparency.
I know digital audio is a thing of controversy, but its here to stay and if set up properly, excellent.
How the sound interacts in the room is much more accessible and controllable now than it was in 1960! The understanding of how our ears react to short term reflections was unknown in the 1950s. The research on the human hearing rules in the last 60 years has really helped!