Germanium OCD

A very helpful thread. Thanks for all your input. I think I might give this a go with a V2 layout. How could one implement a switch to switch between V2 and Custom GE?
 
Assuming I am correct about the connection of the diodes, you would just wire up a DPDT switch to jump across both diodes.
 
Assuming I am correct about the connection of the diodes, you would just wire up a DPDT switch to jump across both diodes.
so basically drill them together asymmetrically and connect them to lug 1 & 4 of the switch and then one wire between lug 2 and source (transistor 1) and between lug 5 and drain (trainstor 2), right?
 
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Those Ge diodes have a single green band, yes? That would make them Д9Ж (D9J). They're hard-wired to the MOSFETs (Q2 & Q3). The diodes, MOSFETs and wires are glued down as a strain relief. 'Cuz clear goop would just be silly.

Sure are a lotta extra parts on that board compared to an OCD or Alpha Drive.
Whatever kind of diodes these may be Mike Fuller wrote on Facebook that the Forward Voltage is 0,35 V.
 
I am still scratching my head. How would I wire a dpdt switch if I'd be using this layout from Effects Layouts? And where would I cut a trace?: PCB-Fulltone OCD V2.png
 
I am still scratching my head. How would I wire a dpdt switch if I'd be using this layout from Effects Layouts? And where would I cut a trace?: View attachment 32304
you wouldn't need to cut a trace, you'd use two of the pads of Q3 and Q4 since those are what you're modifying.
EDIT - I'm wrong and will rephrase once I find some paper
 
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I am still scratching my head. How would I wire a dpdt switch if I'd be using this layout from Effects Layouts? And where would I cut a trace?: View attachment 32304
So here's one way to do it, although it takes four 2N7000s instead of two, which I'll figure out next, but this is basically how you'd do clipping mods where you just fly different sets of diodes on the DPDT switch itself IMG_6238.jpg
 
Nice, this looks good. With Q3 & Q5 "source" you mean DG-Pad?
No I mean the actual S leg of the transistor, you'd solder in D and G, then bend the S leg up and solder a wire from it to the center lug of the DPDT switch.

EDIT: also from the EffectsLayout layout, it's Q3 and Q4, not Q5
 
No I mean the actual S leg of the transistor, you'd solder in D and G, then bend the S leg up and solder a wire from it to the center lug of the DPDT switch.

EDIT: also from the EffectsLayout layout, it's Q3 and Q4, not Q5
My mistake, I meant Q4 and wrote Q5 :rolleyes:

Like this?: Bildschirmfoto 2022-09-15 um 21.04.01.jpg
 
My mistake, I meant Q4 and wrote Q5 :rolleyes:

Like this?: View attachment 32313
not quite, you won't be touching the "G" pads at all (or rather, you'd solder the "D" and "G" like normal into the board).

You won't solder the "S" legs into the board, instead you'll bend them up and solder wires from them to the center lugs of the DPDT switch.

Then the "S" pads on the board will be wired to the bottom lugs of the DPDT switch.

Both diodes will be facing the same way, with their cathodes attached to the top lugs of the DPDT switch.
 
not quite, you won't be touching the "G" pads at all (or rather, you'd solder the "D" and "G" like normal into the board).

You won't solder the "S" legs into the board, instead you'll bend them up and solder wires from them to the center lugs of the DPDT switch.

Then the "S" pads on the board will be wired to the bottom lugs of the DPDT switch.

Both diodes will be facing the same way, with their cathodes attached to the top lugs of the DPDT switch.
Ok, now I understand. Thanks

Bildschirmfoto 2022-09-15 um 21.51.46.jpg
:)
 
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Ok, now I understand. Thanks

View attachment 32318
:)
If you’re using D9 diodes that’s perfect, since the stripe is on the anode on those diodes and you want the cathodes connected to the top lugs

If you’re using 1N34s or others, the diodes will be flipped from that diagram wit the stripes pointing up, either way it’ll be good to test and double check
 
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