fuzz pedal low output problem

[deadtemple]

Hello everyone,

I tried to build a fuzz pedal t and have experienced some issues with it, which is
the fact that, it's fine when it's bypassed, but when I switch it on, even though the LED turns on, the output is really low.
I have to crank up my 60W amp to 90% percent to hear the pedal working.

Even though I'm fairly new to pedal building, I managed to succeed in completing even more complicated projects before.

I checked the connectivity with a multimeter and couldn't find any malfunctioning components. I double checked if the wiring is correct like 100 times.

I just don't know where to take it from here, any ideas what to do?

link to the project:
http://www.ghosteffects.co.uk/pdf/si_pep_box_pcb_guide.pdf



Photos:

[PRR]

Welcome to the forum!

> output is really low.

Sadly it is hard to begin to guess without knowing what is in there. The build-doc you linked doesn't really show the circuit. That website doesn't seem to have the circuit. I went by what it is "based on", and found this:
http://forum.musikding.de/cpg/albums/userpics/16602/germaniumpepbox.png

Find the 9V rail. It must be NEGative 9V measured to ground (jack shells). (Which means you can't power this box with other boxes on a common +9V supply.)

The Bases of both Q1 and Q2 should be near 0.1V-0.2V.

The Collectors of both Q1 and Q2 should be above 1V and below 8V. (This type bias is not very precise, so you may have to trim.)

[deadtemple]

Thank for your prompt response and help.

However, I dont fully undersand what you've said.

How should i power the circuit then?
I tried plug a 9V battery to a dedicated battery clip
But it clearly doesn't work.

Please help

[balkanizeyou]

From the build document:

The circuit is negative ground and can be powered with a 9v battery or a 9v DC adaptor with a negative tip.

So the circuit is "normal" negative ground & you don't need to worry about that part. The wiring from the build document should work, although it's kinda misleading (the labels "+9V" and "-9V" suggest a bipolar supply - it should be +9V and 0V or GND).
What transistors do you use? Did you check their pinout? And please check both transistors' voltages and see if they match Paul's suggestions.