ROG's tube to FET in reverse? Idea for using submini triodes.

[svstee]

Can I use a submini triode in a ROG type circuit? Some major modifications will need to be done of course, heater issues being the first that spring to mind, but is the idea workable? It seems odd to me to mod for tubes a SS circuit adapted FROM tubes to SS, but whatever. Looking at this http://www.runoffgroove.com/fetzervalve.html I see no reason my plan won't work, but aside from getting required voltage to the heater, I'm not sure what else needs to be done. I think I would do something simple like the Fetzer Valve to start.

[anchovie]

Why not start with the original tube amp schematic? No point translating from French to German and back to French again when you could just speak French in the first place!

[Jered]

Why not start with the original tube amp schematic? No point translating from French to German and back to French again when you could just speak French in the first place!

hehehe.........exactly.

[Renegadrian]

That's what I did with my TUBE STAR high gain pedal...Started with a Mesa Boogie Schem and went along with some changes and getting rid of the unnecessary...You just can do the same!

Try to study and recreate something like this...
http://www.kbapps.com/audio/schematics/tubeamps/fender/images/princeton5f2a.gif

[frequencycentral]

To answer the OP's original question - there's no reason not to try it. Broadly speaking FETs and tubes are interchangable given the limitations of each. Breadboard it first, as the resistor values will differ. It may not end up sounding just like a Fender (or a Fetzer), but it should sound good and you'll learn a hell of a lot from it.

One of the inspirations behind my Vintage Vibe submini tube vibrato was mac's 'Fet Phaser Idea' thread, at this very moment I have a four stage Vintage Vibe on the breadboard (the original was two stages), and I'm referring to mac's schematics, among others, for how to get it phasing.

So I say go for it, but also refer to the original Fender schematic, and consider a voltage multiplier to get into HV turf where tubes shine - though it should still sound good at LV. Runoffgroove's triode to JFET stuff is cool, if it's inspired you to do JFET to triode stuff - even cooler.

The only caveat would be that the Fetzer uses only one FET (triode), so why not consider finding a design that uses an even number of FETs (triodes) to get the most out of you submini dual triodes?

Rick



EDIT: The Fender schemo that ROG based the Fetzer on uses a 12AX7 high mu, which is closer to 6112 than it is 6111.

[Ripthorn]

I am actually going to be doing this for my next project, I am going to do a submini version of the DieFET (since a decent Diezel schematic doesn't appear to be in existence).  I say go for it, it only makes sense.

[svstee]

Well, I'm picking up some single triodes soon, that's why a was attracted to the fetzer valve. And the fact that its really easy.