Starved Triode w/ op-amp

[oldsoul]

I came across this design which has ben mentioned a bit here. http://www.valvewizard.co.uk/Triodes_at_low_voltages_Blencowe.pdf Much thanks to MerlinB as he answered some novice questions of mine via email concerning figure 9 which I intend to build. Upon further reading of this article I realized that the circuit in fig 5 utilizing dual-op amps would be more appropriate for a guitar pedal. My question is where you would put a volume pot? Also is it assumed the heaters would get 12V?

[Groovenut]

For strictly level control, the volume pot would go at the end of the circuit just prior to the output jack. For gain control, there are lots of options.

Yes the heaters would need to receive 12V AC or DC. DC is more convenient if you are planning on running the circuit on the same supply as the heaters.

[oldsoul]

Thanks! So that would go right after C5 correct? One other question about this circuit. Is R3 a 10K trim pot?

[aron]

Yes after C5. R3 does seem like a trimmer to me.

[aron]

You can check this out too:

http://www.diystompboxes.com/smfforum/index.php?topic=11857.0