Hi everyone,
Sorry for another noob question.
I built a NPN Si Fuzz Face using this scehmatic: http://fuzzcentral.ssguitar.com/fuzzface/fuzzfacenpnschematic.gif
Overall it works well and the sound is very good, but only when the Fuzz pot (1K lin) is maxed out. As soon as I turn down the pot, from 90% and less, all the "distortion" is gone and a "muddy" non distorted sound is produced.
1. Is this normal?
2. Would changing the pot value (maybe using a bigger value?) help with it?
Again, sorry for the noob question, I think pots and the way they work are the hardest thing to grasp at this early stage :-\.
Cheers
http://www.geofex.com/Article_Folders/fuzzface/fffram.htm
Maybe this will help. Gain is important to the original fuzz face circuit. That is, the gain of the transistor. You might not have enough gain.
I used a 2k pot because thats all I had at the time for my fuzz circuit, and it allowed more range for fine tuning, but then the DC bias changes.
What transistors are you using?
Hi, thanks for the reply.
I used a BC108 and a 2N5088 simply because they sounded better (I mean I didn't measure their gain).
At first I used 2 BC108s but the sound was horrible, and with 2 2N5088s the sound was good but more like a distortion and less fuzzy. A combination of the two seemed to produce the best results.
Thanks for the info, I will study the article later on.
imo, take out the 1k fuzz pot , put a 1k resistor and the 22uf straight to ground instead...
now add a 250k pot at the input of your circuit..(pre-gain...) it has a much better control over the gain, regardless of hfe etc.....
the fuzz pot is useless imo.. ;)
Quote from: kapsel on July 22, 2013, 04:03:11 AM
Hi everyone,
Sorry for another noob question.
I built a NPN Si Fuzz Face using this scehmatic: http://fuzzcentral.ssguitar.com/fuzzface/fuzzfacenpnschematic.gif
Overall it works well and the sound is very good, but only when the Fuzz pot (1K lin) is maxed out. As soon as I turn down the pot, from 90% and less, all the "distortion" is gone and a "muddy" non distorted sound is produced.
1. Is this normal?
2. Would changing the pot value (maybe using a bigger value?) help with it?
Again, sorry for the noob question, I think pots and the way they work are the hardest thing to grasp at this early stage :-\.
Cheers
was just writing the same thing (sadly, that happens with a bunch of builds, which is why you'll read a lot of posts here saying that the fuzz knob is useless. many set it at full and use a pregain like this:)
here's an example:
http://www.freeinfosociety.com/electronics/schematics/audio/pictures/joegaganeasyface.gif
in addition, more on the si version, when the vol is below the top 25%, it can also get a bid muddy. you can put a small cap (try .001uF to start) from wiper of vol pot to the non-grounded side. additionally, you can try a 250K pot instead of 500K
Ok, very useful comments, thanks a lot guys, I will try these when I get back home :icon_razz:
A 1kC, i.e. reverse log taper, is better than 1kB (linear) which in turn is better than a 1kA audio/log pot.
Quote from: nocentelli on July 22, 2013, 06:05:06 AM
A 1kC, i.e. reverse log taper, is better than 1kB (linear) which in turn is better than a 1kA audio/log pot.
Small Bear sells a reverse log 1k pot exactly for this use.
Al