Mike McLane
Active member
Wooohoo! Thx!BTW, if I'm wanting to run my Part Acc into a power amp do I want to create a bypass toggle for the 220K resistor there, too?
5F6/JTM45
- Thread starter Mike McLane
- Start date
Wooohoo! Thx!BTW, if I'm wanting to run my Part Acc into a power amp do I want to create a bypass toggle for the 220K resistor there, too?
vigilante398
Authorized Vendor
Either that or a trimpot to attenuate it down to more pedal-useful levels. Trimpots are what I do in my "commercial" units.
BTW, if I'm wanting to run my Part Acc into a power amp do I want to create a bypass toggle for the 220K resistor there, too?
Mike McLane
Active member
A variable resistor, not a voltage divider. . . yes? A250K? Would my ears tell me the best output for a particular (Class D) power amp or do I want to hook it up to a oscilloscope and test for line level (3.5v p-p)?
vigilante398
Authorized Vendor
I use 500k trimpots which are all linear taper, but yes hooked up as a potentiometer, not a variable resistor. Use your ears, they'll tell you what to do.
Mike McLane
Active member
But my wife already tells me what to do?!?!?!?!? 
Mike McLane
Active member
Curious. . . in noting the use of the fixed 220K in-line resistor in the Particle Accelerator why 500K and not 250K? Just a little extra "choice" in the matter?
I think I have got WTYS selective Hearing loss!But my wife already tells me what to do?!?!?!?!?
Mike McLane
Active member
Would appreciate feedback on the wiring of the cathode follower (the area in the RED box). Did I get it right?
vigilante398
Authorized Vendor
Nope, but close. Pin 6 of the tube needs to tie directly to HV, not to pins 1 and 7. Pin 7 does tie directly to pin 1 though. Tying pins 6 and 7 together will prevent the whole thing from working.
Mike McLane
Active member
Just seein' if you were paying attention 
(ha ha). I see what you're saying. . . . Thx!! I assume I can pull that HV (full HV, not post plate resistor) from anywhere on the board?? I've since redesigned the layout so that an "HV buss" runs down one side of the board and a "GRD buss" runs down the other so the current flow of certain segments are flipped relative to conventional amp layouts. Given that the pots will lie directly against the backside of the board with the tubes flanking either side this seemed to make more sense than the conventional layout scheme. Seems to have more economical wiring, shorter runs.
(ha ha). I see what you're saying. . . . Thx!! I assume I can pull that HV (full HV, not post plate resistor) from anywhere on the board?? I've since redesigned the layout so that an "HV buss" runs down one side of the board and a "GRD buss" runs down the other so the current flow of certain segments are flipped relative to conventional amp layouts. Given that the pots will lie directly against the backside of the board with the tubes flanking either side this seemed to make more sense than the conventional layout scheme. Seems to have more economical wiring, shorter runs.Wife Tells You Something.
vigilante398
Authorized Vendor
Yessir.
Mike McLane
Active member
People who have heard me play would tell you that’s a good idea