Increase output volume of fuzz face circuit

Started by eightsevenzero, August 29, 2021, 11:58:19 AM

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eightsevenzero

Just built up a turret layout of a PNP fuzz face with external bias knob for Q2. Works great but at some settings of bias the volume drops below unity, and even at proper bias there's not much room on the volume knob (which I know is typical). I did some reading and saw that I could swap the arrangement of 470r and the 8.2k Q2 collector resistor but I'm using a 2.2k and 10k pot for that. I assume I could still tag the 470 just before the Q2 collector but I was wondering if there's any other way to boost the volume of the fuzz face circuit short of something like adding a JFET booster on the end. I'd really not do that if I didn't have to!

antonis

Volume is considered signal amplitude (peak-to-peak voltage)..
In case of your  Q2 Collector is biased at about supply midway, there isn't any room for Volume raise.. :icon_wink:

P.S.
By implementing 2k2 & 10k instead of 470R & 8k2, you lower voltage dividing effect from 0.95 down to 0.82..
It might sounds good to your ear but it also sounds lower..
IMHO, a boost configuration for 15% (1.2dB) should be needless..
"I'm getting older while being taught all the time" Solon the Athenian..
"I don't mind  being taught all the time but I do mind a lot getting old" Antonis the Thessalonian..

CheapPedalCollector

Hook the output cap directly to the Q2 collector.

antonis

Quote from: CheapPedalCollector on August 29, 2021, 02:08:26 PM
Hook the output cap directly to the Q2 collector.

Maintaining 12k2 Collector resistor..??
"I'm getting older while being taught all the time" Solon the Athenian..
"I don't mind  being taught all the time but I do mind a lot getting old" Antonis the Thessalonian..


Big Monk

You could also use fixed resistors for the Q2 voltage divider that gives higher output (this larger 470r value) and tweak bias at Q1 for Q2.

Use a 50k pot in series with a 10k resistor for the collector on Q1 and say a 1.2k and 7.5k for the fixed voltage divider on Q2 collector. 
"Beneath the bebop moon, I'm howling like a loon