Will we need another fuzz face derivative? The reply is a convincing NO unless of course there’s something totally new to become offered that provides this tired old device newer and more effective existence.
Among the issues with the fuzzface circuit would be that the best seem originates from germanium transistors, that are difficult to get, frequently leaky and vary in character with temperature changes. Without doubt the nicest seem originates from Ge devices however these limitations can be challenging to beat, specifically for a bginning builder. An easy solution is by using plastic transistors but there’s unanimous thought that Si devices alllow for a significantly harsher seem.
The Fuxx Face was my original attempt to make a fuzzface clone with plastic transistors which had a good but more flexible tone, and contains offered well for the reason that capacity. Within the six or seven years since i have printed that design I have think of a variation that’s nearer to the initial fuzz but has smooth distortion charactersistics.
One trouble with plastic transistors would be that the gain is usually way too high to find the best seem inside a fuzzface. I measured a bag filled with 2N3904 transistors and also the minimum hfe was 250. Other plastic NPN transistors which i had on hands measured even greater. Gain of 85 to 120 is believed to create the very best seem within this circuit.
A fast search of my sources switched in the MPS2369, with a minimum hfe specs of 85. I purchased twelve from radioshack.com plus they measured in the plethora of 110 to 120 for gain – ideal for fuzzface use. The MPS2369 may also be known as a 2N2369 or PN2369. Just substituting this transistor rather from the usual 2N3904, 2N5088 or BC108 can make an big improvement in tone. There are many other plastic transistors concentrating on the same gain specs that’ll be appropriate with this circuit.
I made the decision to accept idea a step further for that YAFF, and altered the fundamental circuit slightly to include a few resistors, R7 and R8. The 100 ohm R7 resistor induces some local feedback into Q1 which cuts down on the gain. R8 has got the same aftereffect of Q2. By utilizing a tiny bit of degenerative feedback, the gain is decreased and also the response from the circuit is much more helpful for milder distortion effects.
Observe that the need for R3 continues to be altered in the original fuzzface to create the bias in the collector of Q2 at 4.5v. It might be essential to tweak the need for this resistor slightly to obtain the bias perfect, though any current around the collector from 4v to 5v is going to be acceptable. Around the first prototype, R3 was reduced to five.9k to obtain exactly 4.5 from the Q2 collector for testing purposes.
Exactly what does it seem like? I’d a shootout by having an original 1972 Fuzzface which contains BC108 transistors and also the YAFF clearly was the greater sounding effect. Its only drawback was that gain and fuzz wasn’t as extreme in the max setting from the Fuzz pot. The YAFF was smoother having a tone a lot more like a Ge version and with a decent selection of settings available. Build “Another Fuzz Face” and provide another seem for your clone tone.
The various components layout and pcb have finally been added. The capacitor C4 isn’t around the schematic and it was incorporated to supply extra filtering if the exterior power can be used. Any value from 22uF to 470uF is okay. Around the input, pads are supplied for any 1M pull-lower resistor to avoid pops once the footswitch is toggled. The pads labeled A and B are just another output towards the volume control.
If jumpers can be used for R7 amd R8, this board may be used to create a standard fuzzface.
Jim Dunlop Fuzz Face Distortion Guitar Pedal
- David Aparicio: Love that, what’s that chord progression at the beginning?