DIY fuzz build problems...HELP!!

[WolfCathedral]

Hey guys, just built my first pedal and when I plugged it up I get no dry signal when pedal is off but I get the effect and signal when it is engaged. Is this a switch wiring issue? Also, When the switch was engaged I got the fuzz but when I would strum hard, the volume would die out immediately. If I played very soft I would hear the full signal....what kind of issue is that? Thanks!!

[moid]

Please take my advice with a pinch of salt because I'm a beginner too, but the lack of sound when the stompbox was in bypass (was for me at least) an issue I had made with the way I wired the 3PDT footswitch - so check the cables are all correct there and nothing is accidentally touching lugs that shouldn't be touched.

I can't help on the other issue, good luck!

[smallbearelec]

There are an awful lot of fuzzes out there...It's hard to begin to help without knowing what you built. Once we know that, we'll want to see voltages at various points in the circuit. See the "Debugging - What To Do When It Doesn't Work" thread at the top of the board.

[bluebunny]

Welcome, Wolf.  Do what Steve (sbe) says and follow the debugging thread - it really works.  As for your switch wiring hypothesis, yes, this could be the case.  Take some pictures and post them so we can take a look for you.

(You'll need to host your pictures somewhere - imgur or postimage are recommended by many folks around here.  Then use the Mona Lisa button to give you a pair of [IMG] tags; put the URL of your picture in between the tags.)

[WolfCathedral]

Thanks guys. It's a hot chili cone fuzz pedal. I got it from Mammoth Electronics. I fixed the true bypass issue but I still have volume loss when I pluck the strings hard. When I pluck them soft all of the sound comes through. Any idea what that could be?

[WolfCathedral]

Hot chilicon fuzz* autocorrect :/

[smallbearelec]

Thanks guys. It's a hot chili cone fuzz pedal. I still have volume loss when I pluck the strings hard. When I pluck them soft all of the sound comes through. Any idea what that could be?

Likely something is not biased correctly, and we don't know why. I see that this board is from guitarpcb.com, and Barry has an extensive forum and troubleshooting area for his designs. You might want to gather the information you need on bias voltages and consult with other people who have built the pedal.

[WolfCathedral]

thanks! I will do that. Do you mean biasing the trim pot i installed or like the transistors need biased?

[smallbearelec]

Do you mean biasing the trim pot i installed or like the transistors need biased?

The notes on this PCB indicate that no trimpot is needed. If you added one, that's mistake #1: Don't mod a vetted design until you have it working as the designer intended. I'm thinking that one or more of the devices is mis-biased because of a misplaced component, a soldering error or something I haven't though of. Looking at the voltages on the devices will indicate where the problem(s) are.

[WolfCathedral]

Well in the build instructions it stated to add the trimpot instead of the resistor for "greater flexibility" :/ i might try and put the resistor there instead.

[WolfCathedral]

Ah! I might have found something. C1 states in the instructions that it needs a 10n 63v cap. The one they gave me is 10n but its 100v. Will that cause something like this?

[WolfCathedral]

C7 is like that as well. 8n2 as called for but 100v instead of the 63v is says it needs. Could that cause it?

[Outlaws]

Ah! I might have found something. C1 states in the instructions that it needs a 10n 63v cap. The one they gave me is 10n but its 100v. Will that cause something like this?

no

[WolfCathedral]

thank you for your succinct response.

[Passaloutre]

The longer response is that the voltage rating of the cap doesn't matter. That's just the maximum voltage you can put across the cap. Since we're dealing with a 9 volt circuit, the difference between a 100 volt cap and a 60 volt cap doesn't matter, as long as the capacitance (farads) is the same.

[bluebunny]

Follow the debugging thread.  Post your results back here.  Pictures too.  We'll get it sorted.