Dual channel od problems

[205]

Hi all,
This is my first post so thanks in advance.
Just wondering if anyone can help. I've just finished a dual channel sd-1. What I did was took a stock sd-1 (actually a cheap Daphon od20 which is a total replica of a sd-1) and added an extra drive pot and level pot using a 3pdt switch to switch it all in with an LED. The original pedal is stock I just added the extra components as shown below:


My problem is I'm experiencing popping when the new pots are switched on. I've tried removing the LED, still pops and also tried the pull down resistors, still pops.
Just hoping someone will notice something on the wiring which would be causing this. Also is it a no no mixing mechanical switching with boss type switching??
As far as electronics go I'm still a bit green I can get by reading and copying a layout ( I've built a few pedals) but I'm no expert on the science of it thats for sure.
Anyway hope someone can help. Cheers Dave

[205]

Tried removing the LED again, just to make sure ,but still having the same problem...POP!

Has anyone had any problems with the BYOC dual tubescreamer mod popping when switching in the extra pots?
If so what was the problem?

[205]

Ok, I eliminate the LED from the circuit, it still popped and then I eliminated the extra level knob.....same problem. 

I then eliminated the extra drive knob from the circuit, POP GONE! So there is my problem the popping is caused by switching in the extra drive knob.

So I tried swapping around which lugs were used to switch it into the circuit but either way I still have the same problem.

Any suggestions as to how I should switch in that added drive knob???

I shall keep trying.

[GibsonGM]

I'm not really seeing the switching (it's really early here!), but look at the modified tube screamer schem, Fulldrive 2.  There's a 1nf cap in there  where the pots join, and might help suppress any DC riding around in there :pop:  I like how that's set up for drive switching...could help yours.

[d95err]

It's a bit difficult to follow the switching arrangement from only the layout. Could you post a simple schematic of the switching and the relevant nearby components?

[205]

I'm not really seeing the switching (it's really early here!), but look at the modified tube screamer schem, Fulldrive 2.  There's a 1nf cap in there  where the pots join, and might help suppress any DC riding around in there :pop:  I like how that's set up for drive switching...could help yours.

Hi GibsonGM, thanks for the help. where is this schematic you mention? I've searched Diystomboxes schematic page but there are so many TS-9 variations its hard to tell which one you are talking about 

It's a bit difficult to follow the switching arrangement from only the layout. Could you post a simple schematic of the switching and the relevant nearby components?

Apologies for my lack of electronics knowledge, I'm still learning.
But what I've done is taken a bone stock sd-1 and just added the extra drive pot, level pot and LED which is switched in with an added 3pdt footswitch, like the BYOC mod below:

The sd-1 pedal is all stock so i'm still using the original flip flop (i hope thats what its called) switching to bypass the effect, the tone pot hasn't been touched, nothing. All I've done is added the extra components like they've done above. The original switch does not pop it's only the added 3pdt which is popping.

It all works, so I'm happy about that, it's great having one overdrive with two channels! Except for the popping!    
I'll keep trying any way.

If someone could suggest something that would help it would be much appreciated...cheers.