Tube Challenge!!

tomg efm3 at
Mon Nov 1 23:18:41 CET 1999

Thinking about it again, it is a vco in a way... The presence control
could be called resonance and it's one on the reasons Marshall
amps are still the best sounding guitar amps you can buy. It has
a res control!   Anyway enough res and the power amp oscillates
apply a voltage to the input and you have a power-vco. The same
principle can be applied to preamp circuits. A tube vco/vcf/vca
should not be a problem. If I had the time I might take up your
challenge but the diy-pcb group would have a fit.


>'s not a vco, but if you want a killer guitar amp..
>>Happy Monday, everyone!
>>I have been thinking about this tube vs solid state thing 
>>all weekend. (Oh no!)  I would like to send out a challenge 
>>to the tube gurus out there who are "carrying the torch". 
>>(Arrggh, not ANOTHER tube/solid state flame war!)
>>There are numerous sites on the web where DIY solid state 
>>projects can be found, enabling anybody with some time and 
>>motivation to build basic but effective synth stuff. But 
>>what about tubes? I have not searched exhaustively for tube 
>>projects in particular, so maybe I have missed something, 
>>but there just does not seem to be a lot out there.
>>Here is my challenge; I would like to see somebody come up 
>>with some synth DIY tube projects on a website designed for 
>>the tube novice. For starters, how about a VCO built 
>>entirely from a few common tubes (12AX7 etc.), that 
>>produces various waveforms, with V/Oct scaling and FM 
>>input. Details regarding design and features could be 
>>discussed on the list, for those interested, just as is 
>>done for solid state projects. And judging by what tubes 
>>sound like to me, I think that this could be an incredibly 
>>PHAT sounding oscillator. If successful, a whole series of 
>>modules could then be designed, allowing one to build 
>>their own all-tube modular synth. Then everyone could see 
>>for themselves what the advantages and disadvantages are.
>>So, any brave souls up to the challenge? 
>>Doug (obviously thinking WAY too much) Tymofichuk
>>dougt at

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