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DIY Stompboxes => Building your own stompbox => Topic started by: terryward on October 08, 2011, 10:15:27 PM

Title: Fuzzrite Build - Is this the right diagnosis?
Post by: terryward on October 08, 2011, 10:15:27 PM
Hi all,

I'm building a Fuzzrite pedal using the kit from General Guitar Gadgets.  I've made no substitutions or modifications to the schematic.  The project page is here:  http://www.generalguitargadgets.com/projects/73-fuzz-tones/257-mosrite-fuzzrite

Schematic:
http://www.generalguitargadgets.com/pdf/ggg_secf_sc_mrfr_si.pdf?phpMyAdmin=78482479fd7e7fc3768044a841b3e85a

Layout:
http://www.generalguitargadgets.com/pdf/ggg_secf_lo_mrfr_si.pdf?phpMyAdmin=78482479fd7e7fc3768044a841b3e85a

I'll be perfectly honest and admit I followed the layout over the schematic, this being only my second pedal build.

After wiring it all up, I had power, but when I engaged the pedal, the output volume dropped at least in half, and there was barely any fuzz to be had.  To get any amount of fuzz I really had to dig into the strings, and that was with volume and fuzz controls turned up all the way.

The transistors that came with the kit were 2N2369A, with a pinout of 1-Emitter, 2-Base, 3-Collector.

Here are the voltages on the transistors:

Q1
1       3.40
2       0.55
3       0.00

Q2
1       3.39
2       0.55
3       0.00

Now, based on Fuzzrite transistor readings I've found by searching the forum, it seems like my transistors are in backwards.  That is my readings should be


Q1
1       0.00
2       0.55
3       3.40

Q2
1       0.00
2       0.55
3       3.39

SO, does the problem I described seem to correlate with my diagnosis of reversed transistors?  I want to be sure before rotating the transistors, in case that's not actually the true problem.

Thanks!
Title: Re: Fuzzrite Build - Is this the right diagnosis?
Post by: John Lyons on October 08, 2011, 11:02:06 PM
The collector should show the most voltage.
So yes, looks like you have them in backwards.
Title: Re: Fuzzrite Build - Is this the right diagnosis?
Post by: terryward on October 09, 2011, 02:25:48 AM
Thanks for the reply!  I switched them around and it seems to be working properly now.
Title: Re: Fuzzrite Build - Is this the right diagnosis?
Post by: John Lyons on October 09, 2011, 11:32:40 AM
Cool!  :icon_biggrin: