SOLVED Help with Dr. Trebor (aka Pharmacist) - mach schau not working

[jeff1280]

Hi,

sorry to hijack this thread but Dr. Trebor/Pharmacist threads are quite hard to find ...
This is actually my second build, my first was Son of Ben and it worked right away. So I got cheeky and tried Dr. Trebor (I got the PCB and all parts from musikding in Germany, so good quality with all parts).
However I'm having trouble with the "mach schau" circuit. The normal channel is working alright except the volume pot but I suspect that this has something to do with "mach schau" not working.

I suspect the problem lies within the wiring of the mach schau switch. For the bypass-switch I used the EZ 3PDT board but for the second switch there was no board and no documentation. So I wired it as followed:
Row one of the switch to lugs 1-3, the middle row to lugs 4-6 and the third row to lugs 7-9, always left to right on the switch.

If I engage "mach schau" the pedal goes mute and the second led won't light up. I'm not really good at trouble shooting (yet) but you've got to learn somehow. I measured voltages and what got me curious is that R36 measured 9 V at it's input and about 1.8 V at its output when engaged.
R35 always measures about 7.4 V at its input and output although the value of it measures correct (4.7k).

Should I post some images (if so what would you need) or would certain measurements help?

The normal channel sounds alright by the way, no spluttering and a very "voxy" tone, just as I expected

Any help or hint is much appreciated.

Thanks
Jan

 

[music6000]

PedalPCBMania have a lot of issues with their boards, someone else had problems building it here to!???
The Pharmacist is a far superior PCB & should not be use in the same sentence as the questionable Dr Trebor PCB!
Sorry to be the bearer of bad news.
This is a wild guess but it may work wired like this???
Your PCB is numbered 1 2 3 4 5 6 7 8 9
Below is the standard numbering for 3PDT switches:

 

[jeff1280]

Hi music6000 and thanks for the quick reply and the help with the switch numbering. That actually did the trick! I thought the numbers were rotated by 90° ... I sort of came to that conclusion myself by the strange behaviour of the led lighting up while measuring the lugs within themselves but couldn't really make sense of it - until your image and now everything works

As I'm a novice in pedal building I can only rely on ready packed kits (for now ;-)). The Son of Ben was a way easier job, not only because of the easier layout but mainly because of the better documentation by pedalpcb. If I had the choice I'd always gone for the pharmacist but it isn't available, at least here in Germany ...

In the end I like the result very much. I know the original Dr. Robert and this one definitely comes very close.

 

[Feral Feline]

...
The Pharmacist is a far superior PCB & should not be use in the same sentence as the questionable Dr Trebor PCB!
...

... same sentence ... wait ...

.