Dumbleator specifics?

[NorCalTuna]

Hey guys- I'm building a loop for my d-clone and have a schematic (below) which looks good, makes sense, but was wondering what sort of voltages I should be shooting for. The send cathode follower seems like it should be about 280 or 300 and the return section more like 180. The cathode voltages would be good to know too.

Does anyone have experience with this circuit? It seems like it should be a nice weekend project : ^)

thanks in advance!

[MattT]

I have a little experience with it.

First off: I've never built one with those bright caps across the Send/Return pots but I've never needed those bright caps. My guess is that you won't need them and it might alter the tone too much if you do. But you can always leave them in the OFF position so I guess they couldn't hurt.

Sometimes that Send circuit can be a little low on headroom and I've had success increasing that 10K resistor to like 27k-33k and increasing that 1.5k to 2.2k or so.

I've also used a 500k Send pot (just because I didn't have a 250k at the time) and then when I later swapped in a 250k I felt it didn't sound as good. So I often use a 500k there.

The D'Lator had a power supply that had a different 'node' for each triode. I can't remember the specifics but IIRC it had the Return node first in the string (higher voltage) and then the second 'node' was the CF and the dropping resistor between the two nodes is pretty big (like maybe 47k or even more). For the supply voltages I'm pretty sure you want about 340vdc for the Return and about 280v on the CF. Somewhere in those ballparks. But I've run it from one node...mounting lots of stuff right on the socket...and it's been fine that way too (you'll have to run the CF a little high and the GS a little low but it still works fine).

Lastly, I've only built this into my amps...I've never built the stand-alone rack unit. So my experience is limited to that. I usually just run an extra node off of the screen supply and run it all from one node.