and again: tube overdrive an distortion .... ?

[Steben]

One can experiment with mosfets and diodes. Feedback clipping to clipping to ground. Or one can simple build a tube triode preamp and settle with it. Look mom, i have tubes!
But is this truly what we look for?
Of course you simple buy that super amp and go and get yourself a hotplate of power soak.
But buying stuff is not what this forum is intended for is it?

In the quest for holy tone i stumbled again on response curves and clipping.
These two assumptions caught my eye:
- Triodes can hard clip whenever the input goes low enough in voltage (zero current at the anode). TUBES!
- there is no softer clipping than diodes in combinations with resistors. SOLID STATE!
Preamp triode clipping can be as harsh and gritty as anything else. And bloody hell, how many marshalls use diodes in their tube amps in the clipping?
So what's the use?

one thing is for sure: all devices can be useful. simple transistor buzz to tube screamer like circuits with mosfets: sometimes you want fuzz, sometimes gentle overdrive.

But the holy tone is a basic tone. the "Amp" which you use after your "stomp"boxes. Your gentle best friend. The friend that makes your fuzz face sound good at last.

FACT 1: The only true soft clip dynamic bluesrock mush is a full tube power amp including transformer and speaker.
FACT 2: the most musical clean tone without clipping is with no doubt the degressive harmonic content with a prominent second harmonic. Class A Triode in the more lineair region without clipping. Mathematics: power 1.5

This makes me to believe that the best reproduction without a real power amp should be a combination of these factors.

"class A PREAMP stage" -> "linear soft clipping stage"

The preamp could be a real triode of course, no problem. Most simple tube is a preamp tube. Only problem is the supply voltage, which is best a tad higher than 9V, unless you use low voltage tubes.
Fantastic design is the ruby tuby bij sopght amps: http://www.sophtamps.ca/mambo/index.php?option=com_content&task=view&id=28&Itemid=39
LM386 clipping, class A triode preamp. Interesting how the solid state is used for the saturation, thetubes for the clean basic tone.

Solid state preamp is a pain. Response is never in the region of power 1.5. It's either only even harmonics, or way too much odd. Yet there are options.
Interesting ideas:
http://gabevee.tripod.com/sstube.html combining square law and exponential responses
http://www.radiomuseum.org/forum/the_trioderizer_a_solid_state_triode.html extended theory but simple circuit!
and of course: http://www.runoffgroove.com/fetzervalve.html feedback bias in a jfet.