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How to make chip amps sound as beautiful as SE triodes do?

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Kokoriantz:
How to make a chip amp sound as beautiful as SE triodes do?
This is engineering forum and not a place to discuss aesthetics. The Japanese SET lovers analyzed the Marantz 8b in 60's to understand why it sounds as beautiful as a SET to discover the distortion spectrum to be similar . Since Jean Hiraga promoted this idea in his publications, it became for many designers a recipe to follow and that I will apply here too.
The surviving class AB chip amps are now very cheap and good ones, like cheap Italian table wine in cardboard container, makes many happy ,but it is not to compete with class A open loop triodes. These chip amplifiers have only 50db open loop gain at 20khz, once 26-30db feedback applied, it leaves only 24db NFB where 60db is needed for HQ sound.
I added a transistor to the chip to provide the nonlinear Ic/Vbe square law function and add extra 36db NFB to the closed loop. To show its efficiency, the chip stand alone with application circuit has 70uV noise in audio band spectrum, with transistor added it falls to 1uV, all other anomalies are corrected    with the same ratio of 70 fold.
I did realize this amp , with +/-25V and large heatsink the sound was perfect but nothing special, it passed the most difficult music, Mozart's Requiem in perfection, the high frequencies are exceptionally clean but the music lacks enthusiast . I replaced the heatsink with a tiny one and supplied  with +/-20V where the chip dissipates a near constant power of 12W eliminating internal thermal feedback. I truly assure you this tiny amp is adorable. It takes me about 2 weeks to tune an amp, I'll keep updating.
 I have already done similar circuit with LM3886 and 6N6P tube with 250V floating supply, this amp is as good and much simpler.

oz2cpu:
>sound as beautiful  ??

if the goal is to ONLY amplify, and not add or remove anything,
tubes fail, transistors and opamps win

if the goal is to add and remove, affect the sound in a way that some people find nice,
then tubes will most likely win, since they add 2nd harmonics

Kokoriantz:
Look at the spectrum, the main distortion is second harmonic as tubes do.

janoc:
Make DSP filter replicating the distortion response of the tube amp?

However, ultimately you are going to be going against a brick wall because the issue there isn't the "beautiful sound" but that it isn't "tubes" and you thus won't be able to convince anyone who thinks that tubes sound/work better that your "chips" work as good or better as the tube amps.

It would be an exercise in futility, IMO as this isn't about measurements and science but beliefs and personal preferences.  And that's long before you go as far as outright audiophoolery...

oz2cpu:
or just get the real thing and be happy,
the orange glow at night is so much also adding to the total love feeling.
https://fairman.dk/kt88amp.htm

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