First Time Fuzz Face Build - Help Identifying Problem

Started by pastor_ron, November 03, 2012, 08:30:05 PM

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pastor_ron

Quote from: jrod on November 20, 2012, 01:33:14 PM
Cool! Hope you get it working!  :D

Thanks :). No ideas about the low volume?

I checked the voltages into both transistors last night. Like I said, I'm at work, so I don't have them with me, but the voltages into Q1 were close to right on with the GGG targets here: http://www.generalguitargadgets.com/pdf/ggg_ff5_instruct.pdf?phpMyAdmin=78482479fd7e7fc376%208044a841b3e85a.

Q2 was a little low on all 3 pins. The collector was 2.7v instead of 4.5v. Would that affect the volume?

pastor_ron

#21
It's alive!!! IT'S ALIVE!!!

I replaced the wire to lug 3 of the fuzz pot, it was cutting in and out if moved, and re-soldered the tip of the input jack because I saw some stray strands of wire. I plugged it in, got a good bypass, clicked it on (both of the pots were full on) and got gobs of fuzzy goodness at full volume. This is my first fuzz face pedal ever, so I have nothing to compare it to. From 3 o'clock to full on the fuzz knob it gets hairy very quickly, and at max it is ridiculous. I'm assuming this is because of the hfe's of the transistors. But now that it's working I may get some quality germanium transistors and replace the Radio Shack silicons. The only guitar I have at home is a Tele with a bad bridge pickup, but on the neck pickup it sounds good. Tomorrow I'll take it to the church where I've got my other guitars and a tube amp to try it through.

I appreciate all of the help! This has been a major learning experience. Probably won't tackle anything else too soon. Maybe a Distortion+ in the future. For now, I'm going to enjoy this one!  :icon_biggrin:

Pyr0

 8) It's a great feeling when it finally works.

I bet you will build another pedal sooner then you think  ;D

PRR

> overall volume is extremely low.

What is Q2 collector voltage?

The primary adjustment for this is the Q2 emitter resistor. Make it larger, collector voltage rises.
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LucifersTrip

^ he's got it working now, but

"Q2 was a little low on all 3 pins. The collector was 2.7v instead of 4.5v. Would that affect the volume?"

Yes....and the tone will be thinner.

Most people decrease Q2 collector resistor to increase the voltage, but others alter Q1 collector resistor.

Btw, try leaving Q1 silicon and throwing a ge into Q2. Though you won't get the full-on ge tone, it's easier in the beginning.

The higher hfe's you're using will give you a more compressed, mushy, synthy sound. Raising the voltage >4.5V can remedy some of that....and decreasing the 500K vol pot to 200-250K will also help


always think outside the box

pastor_ron

Quote from: LucifersTrip on November 21, 2012, 01:06:11 AM
^ he's got it working now, but

"Q2 was a little low on all 3 pins. The collector was 2.7v instead of 4.5v. Would that affect the volume?"

Yes....and the tone will be thinner.

Most people decrease Q2 collector resistor to increase the voltage, but others alter Q1 collector resistor.

Btw, try leaving Q1 silicon and throwing a ge into Q2. Though you won't get the full-on ge tone, it's easier in the beginning.

The higher hfe's you're using will give you a more compressed, mushy, synthy sound. Raising the voltage >4.5V can remedy some of that....and decreasing the 500K vol pot to 200-250K will also help




Thank you! Adding a trim pot would also help with the voltage, right? I may try that too. I'm wondering if my voltage readings were off because of some bad solder connections. I haven't tried the readings again since it started working. Will do that today and report back, just in case anyone's interested :)

LucifersTrip

Quote from: pastor_ron on November 21, 2012, 09:06:25 AM
Thank you! Adding a trim pot would also help with the voltage, right?

that IS the way to do it....or try different transistors. remember, you should be able to hit 4.5 - 5v with a resistor in the ~ 4 - 15 or 20K range. If you're out of that range, best to try different transistors

Quote
I may try that too. I'm wondering if my voltage readings were off because of some bad solder connections.

possibly, but that usually just causes no or an intermittent connection

Quote
I haven't tried the readings again since it started working. Will do that today and report back, just in case anyone's interested :)

it will probably help someone just like you now or in the future
always think outside the box