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fuzzface transistors

Posted: Mon Jul 16, 2012 9:25 am
by pancri
hi,
i have a jimi hendrix fuzzface, i read that sound better if you adjust the trimmer under the board...
which is the right voltage on the transistors?
can someone tell me how to measure the voltage on a transistor?

Re: fuzzface transistors

Posted: Mon Jul 16, 2012 11:03 am
by HTH
'Better' is subjective to say the least.

Broadly speaking, you want to bias the collector of Q2 to half of the supply voltage, i.e. around 4.5v

However, you may prefer the tone with the collector set at 6v - there is no right or wrong as long as it sounds good to you.

Re: fuzzface transistors

Posted: Mon Jul 16, 2012 5:15 pm
by Roe
yeah, 4-6v depending on taste

Re: fuzzface transistors

Posted: Mon Jul 16, 2012 6:58 pm
by pancri
ok thank you!
how can i measure the voltage on Q2?

Re: fuzzface transistors

Posted: Tue Jul 17, 2012 1:25 am
by yladrd61
Measure with a voltmeter between the collector of Q2 and ground, mine sounds best at around 5.2 V :jimi:

Re: fuzzface transistors

Posted: Tue Jul 17, 2012 7:38 am
by pancri
ok!
is the collector the one covered with a little gum tube ?

Re: fuzzface transistors

Posted: Tue Jul 17, 2012 10:26 am
by HTH
pancri wrote:ok!
is the collector the one covered with a little gum tube ?
Just measure them all till you get the one within the range of 4-6v. The other two (base and emitter) will measure only around 0.8v and 1.4v, so it's easy to identify the collector.