Subj : Re: 3d printing
To   : Moondog
From : Vk3jed
Date : Fri Sep 20 2019 08:18 pm

-=> On 09-20-19 01:29, Moondog wrote to Vk3jed <=-

 Mo> Most musicians choose an amplifier not for it's accurate sound
 Mo> reproduction, but for it's flawed design characteristics (harmonic
 Mo> distortion, uneven frequency response.)  Same goes with vintage
 Mo> speakers. The only time a guitarist wants a clean amp and good speakers

That's true, and the introducton of musician's equipment into a thread that was
originally about the fidenity of recording media (vinyl and digital) really
muddied the waters, because there is a big difference between creation (where
imperfections can be part of the artistic process) and faithful reproduction of
music

 Mo> is when they produce their sound before the amp via effects boards or
 Mo> pedals,and want only amplification.  How it was explained to me was
 Mo> vacuum tubes produce warm even harmonics, while transistors produce
 Mo> harsher odd harmonics.  Some of this is aged information or heresay,
 Mo> due to the changes over the years from germanium to silicon

Tubes have a couple of differences to transistors in practical circuits. 
Firstly, for moderate power levels, tube power amplifiers are often "single
ended", which has the second harmonic as its strongest harmonic. 
Transistorised amps, including MOSFETs are usually configured as a
complementary pair, which tends to cancel out even harmonics.  Not the best for
musicians, who want those even harmonics.  Tube aplifiers also almost aways
have transformer coupled outputs, which are another source of distortion (for
better or worse), due to their iron core.  Modern (hi fi) amps are generally DC
coupled to the speakers.

 Mo> transistors, and CMOS JFETS have been observed behaving harmonically
 Mo> similar to vacumm tubes.  Even among basic bulk components such as op
 Mo> amps there are folks who swear one vendor's version of the same chip
 Mo> sounds way better even though their specs are slightly different.

It also depends on the exact circuit design used.


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