KILIMANJARO LOUD farting/squealing/gated NOISE

P

Pupina

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I just built this project (bought from Musikding); I cannot bias the transistors (Q1 around 50 hfr, Q2 around 100, Q3 around 70hfe....Q1 quite leaking, while Q2 and Q3 are in the average 150mA or so).
All I can have right now is a LOUD squealing/farting/gated noise for the most part of the bias trimmer's excursion.
Could you help me spot the problem?
Thanks
 
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Hi Pupina,
I'm sure someone can help with that. Can you get some clear pictures of the guts? Do you have an audio probe?
They may not be necessary, but it usually does help ;)
 
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I did it but I didn't succeed yet.
I'm trying the right combination of transistors; I'm waiting for the delivery of some GT403B from Romania.
All I understood was that this pedal is very demanding when it comes to transistors.
Are you building the same pedal? did you succeed? (without issues and oscillation?
 
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I have not gotten it yet. I am considering it among with a few other ToneBender MKI or similar boards.
If I go for it, I will order a kit. Just have to hope that the transistors are paired properly then.
I would be interested to hear about your progress so keep posting, thanks.
 
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Got today the GT403B.....nothing different
This damn pedal oscillates at a certain range of the trimmer
Keep away from this pedal or accept the challenge and be ready to fight with gosts....I can't get WHY this pedal does oscillates that way.....
 
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Might be a wild guess and maybe trimming is already enough at Q2, but since you are not happy, nothing to lose?
Set a trimpot of 20k or 30k on R9 instead of 15k. Do some magic gesture. Tweak the two trimpots.
Also measure hfe if possible and have q1 q2 q3 high to low, (tip from Rift project, might be irrelevant) or q2 and q3 the closest ones. (Rift tip as well)
Tweak pots again...
Have you chatted the original makers of the board? I also buy from Das Musikding and they are helpful and patient with me.

I opted for ToneVendor MKI instead. For MKI i plan to replace the 15k on Q3 with a trimpot as suggested for MKII review on Musikding. So 20k should be enough.

Also isolate when testing. Lamps, laptop and computer screens and mobiles etc. At least single coils pick up on anything, not sure how sensitive pedals are.
 
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One more... check instructions for American fuzz 60s pro something at musikding. It mentions adding small caps if there is noise from transistors. They go in parallel with R, so should be "addable". At least test temporary. Socket would be good but extra work. Maybe Musikding has some idea of which Rs and what cap to use

Edit: no suitable Rs i Kilimanjaro as I could see
 
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