question about diode clipping...

[danwelsh]

Hi guys, so I wanna do so diode clipping and i'm stuck.....how the heck do you wire it in the pcb....the board i'm using is an r2g2 which has 4 diodes...I have an on/on dpdt switch and one of guitarpcbs dpdt boards also, do I remove all 4 diodes from the pcb or just two? and also do I have to put jumpers or anything in place of the diodes? If someone could walk me through this it would be very much appreciated.

FYI i have the switch soldered to the dpdt board, I tried taking out a series of 2 and ran wire from the +hole and -hole to the proper pads on the board, and tried other diodes but it's not making any difference in the sound of the pedal at all.

[pedalman]

throw up the scematic and lets have a look

[danwelsh]

here is the schematic

[danwelsh]

I removed the 2 diodes circled.... the pedal is complete, this was a pic I took in the beginning.

[pedalman]

D2 & D4 jump leads and a rotary switch in C13 & C15

            diode             diode           diode
             l     l             l      l           l       l

lead in   l      l----------l      l--------l       l lead out

             l___l             l____l          l____l
            jumper           jumper        jumper

make sure you do 2 of the switches with the same diode like a 1N914

[RobA]

I haven't used the GuitarPCB board and I couldn't find a schematic for it on their site, but I think I understand how it works from the photos they have there.

I'm not clear on one point from your original question, do you want to put the clipping mods on both sets of diodes or just one? If you want to do both sets of diodes, you would need two of these switches.

The wiring of the switch to your PCB is easy. You just remove both diodes from the set (as you've done with one set) and then you can wire the two leads from your switch board to either side of where the diodes used to be. To be safe, choose one of the diodes and wire the leads from the switch board just as if they were one of the diodes. You leave the other old diode position empty.

Do you have a photo of how you setup the switch board? That is more likely where any issues will show up.

[danwelsh]

D2 & D4 jump leads and a rotary switch in C13 & C15

            diode             diode           diode
             l     l             l      l           l       l

lead in   l      l----------l      l--------l       l lead out

             l___l             l____l          l____l
            jumper           jumper        jumper

make sure you do 2 of the switches with the same diode like a 1N914

so...they have to be the same diodes in all 4 positions? What i mean is I couldn't use 2 zeners and 2 1n914s?

[jkokura]

You can use whatever diodes you want in whatever configuration you want. That's the joy of DIY, experimenting to find what sounds good to you.

Jacob

[danwelsh]

here's a pic of the board with the switch, the part circled, i had 2 diodes installed like the other side of the board but removed the sockets and diodes for now until i figure this out

[RobA]

OK, So that looks good. The side you have wired will give you the stock version assuming that you have 1N914's in there. So, now you just need to figure out what you want to do on the other side and then wire that to the main board.

If you want to try symmetric clipping with another kind of diode, like Ge, then you can do the same thing you've done there using the different diodes on the other side. I can't really tell how the board is setup for asymmetric clipping though. You could just solder two diodes together in the same direction as each other and then put them in for one of the positions on the second side and the other position on the second side just being one diode.

You can mix diode types on a side too to get asymmetric clipping.

Also, if the DPDT is an ON/OFF/ON, the center position will bypass the diodes and remove the clipping from that stage. That can be really nice.

[danwelsh]

Got it done.....2 leds and 2. 8.2 zeners.....sounds awesome