Help with debugging Zen drive pedal

[paul84]

Hi all,

I would like to ask you for help while trying to debug my first pedal - the zen drive. Its done from the kit (http://diy.musikding.de/wp-content/uploads/2013/06/zenschalt1.pdf, http://diy.musikding.de/wp-content/uploads/2013/06/zenwire.pdf) which was pretty straightforward, so there should not be mistake in terms of swapped parts etc hopefully
Anyway, the pedal works, but:
- when the pedal is ON there is a significant whiz (hopefully its the right English word - I don't mean hum), even on very low gain setting
- true bypass works without any tone modification

So as its my first build I wanted to ask you few things as I'm not sure what could be the problem:
- could it be insufficient grounding? Should I ground any other way then just connectit 0 power pin with all ground pins on PCB and in/out jacks?
- could it be its not yet built in the pedal box? I just have the board with all connectors and cables on the table?
- kit provided also wires, but none of these is shielded, is it necessary? I.e. wires from jacks to the board?
- i'm powering it with separately bought (quite cheap) 9V adapter, that provides according to my measurements 9,3 V DC

I'm planning to build own audio probe as I found this great idea hear and will start debugging and also learning what each part of the schematic does with to tone, but at the beginning, I wanted to check if there is any big mistake I have done

Many thanks for any help,
kind regards,
Paul

[bloxstompboxes]

I am going to guess that the whiz you hear is AC noise or maybe a hiss. It's possible that the cheap 9V adapter you have might not be regulated, meaning properly filtered to get rid of AC ripple/noise. But, a nonregulated adapter usually measures higher than it's specified voltage until it has a proper load on it. It could also just be like you said and it's because it is not boxed up yet. Try a 9V battery and try boxing it up temporarily if you can. Also, try the debugging page listed atop the page if you still have trouble. We have to little info to go on here. Post that debugging info here and maybe we can better help you then.