drew.spriggs
Well-known member
I may have cooked a little with this one.
CD4049 charge pump, giving me about 58v from a 12v supply. Will probably run it off 9v as...well, you'll see. Less than 10mv of ripple while running it at 60khz; I did try getting to about 100khz, but the oscillator isn't as stable.
Originally designed for a 5678 submini pentode, but they're stuck somewhere in the post. I do have 5672's on hand which I used for testing, but it's got 1/4 of the transconductance so will respond very differently.
Left knob is a dial to go from pentode/UL/triode modes ala. Merlin Blencowe's morph control.
Even though it's the wrong tube, my poor amp
24dB of gain in pentode mode, 12dB in triode mode (UL somewhere in the middle). Will be interesting to see what happens with the proper tube when they eventually turn up. Ridiculously low noise floor too which is nice.
How does it sound? Pretty good so far! Will be interesting to see what happens with the correct tube, but even with this it's absolutely destroying the front end of my amp. Not sure I can put my finger on the EXACT differences I'm hearing between pentode/triode without more listening, but it is definitely sounding different (as well as much louder in pentode mode).
CD4049 charge pump, giving me about 58v from a 12v supply. Will probably run it off 9v as...well, you'll see. Less than 10mv of ripple while running it at 60khz; I did try getting to about 100khz, but the oscillator isn't as stable.
Originally designed for a 5678 submini pentode, but they're stuck somewhere in the post. I do have 5672's on hand which I used for testing, but it's got 1/4 of the transconductance so will respond very differently.
Left knob is a dial to go from pentode/UL/triode modes ala. Merlin Blencowe's morph control.
Even though it's the wrong tube, my poor amp
24dB of gain in pentode mode, 12dB in triode mode (UL somewhere in the middle). Will be interesting to see what happens with the proper tube when they eventually turn up. Ridiculously low noise floor too which is nice.How does it sound? Pretty good so far! Will be interesting to see what happens with the correct tube, but even with this it's absolutely destroying the front end of my amp. Not sure I can put my finger on the EXACT differences I'm hearing between pentode/triode without more listening, but it is definitely sounding different (as well as much louder in pentode mode).
