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Re: More answers

Andy, we do not deliberately add distortion to any amp. Sometimes we find that some distortion (usually lower order harmonic (2nd or 3rd) in small quantities, does not significantly effect the sound quality, so we will make some engineering tradeoffs, such as lower or no global negative feedback, with a tendency for greater measured distortion, but subjectively improved listening performance.
It is an important trade-off, BUT we do not allow distortion on purpose.
What many people do not know or understand is that almost all audio tube amps have inherently LOW negative feedback. This is because the necessary coupling capacitors and output transformer limit the feedback factor to approximately 20dB, due to low frequency instability, or 'motorboating' problems.
When we reduce the amount of negative feedback in transistor amplifiers to this amount, we find that the sound quality improves, IF the actual circuit is linear enough (open loop) to behave at least as well as a tube amp. Why this is so, is complex. It can be TIM, inherently higher open loop bandwidth (reduction of input stage FM distortion), and lowering the generation of higher order harmonics from lower harmonics through the feedback process.
Whatever, we find that lower feedback generally sounds better, all else being equal.
Making virtually zero distortion (for all practical purposes) is relatively easy. Just try to measure any decent IC op amp!
It is a constant struggle to make better sounding products, since we have to make them intrinsically more linear without feedback, operate them in a class A mode, and still have decent, if not ridiculous 'specs' for the marketing department or for THX approval.

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