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previous: Marrk I have some WEP Germaniums (NKT275 ... -- 3/9/1998 6:55 PM

Re: Fuzz Face for the people!

3/12/1998 3:12 AM
MHelin	Re: Fuzz Face for the people! I have some WEP Germaniums (NKT275 equivalent) that test out at 25 in a Fuzz Face clone I constructed, and I like the tone of them very much. It sounds a lot like the '69 pedal demo found on the Fulltone website. I would like to know your experience with the germaniums you have. The gain of 25 is quite low. The 2SA12's I used had gain of 75-90 depending on the temperature - well, it's 12 degrees below zero here in Finland now. I don't think it were an overkill to build a separate adjustable heater for Q1, just like on old analog synths. The 2SA12's are okay for FF (and cheap, too), but I hope my guitar had better PU's. Not all PU's like FF's low input impedance. If anybody ever builds a FF or designs a PCB for it, it would be better to put a 100k preset there for Q1 collector resistor (the 33k one there on orig. FF schematics). This helps to find a good value for the system (consisting of PU's & the gain of Q1). I noticed that with 33k the voltage on C of Q1 was -0.9V, and the base voltage was -0.13V. I then changed that 33k to 100k, and now the Vc was -0.5V and Vb -0.10V. Smaller value (10k) didn't work, as the "noise gate" opened just for the peak. The ECG cross-reference list btw. shows ECG102A to be a substitute for 2SA12, so it would also be a good choice. I guess it's the same thing as NTE102A. On DMZ there are data sheets for the NTE102A/103A parts. -Mikko

3/12/1998 3:12 AM

MHelin

Re: Fuzz Face for the people!

I have some WEP Germaniums (NKT275 equivalent) that test out at 25 in a Fuzz Face clone I constructed, and I like the tone of them very much. It sounds a lot like the '69 pedal demo found on the Fulltone website. I would like to know your experience with the germaniums you have.

The gain of 25 is quite low. The 2SA12's I used had gain of 75-90 depending on the temperature - well, it's 12 degrees below zero here in Finland now. I don't think it were an overkill to build a separate adjustable heater for Q1, just like on old analog synths.

The 2SA12's are okay for FF (and cheap, too), but I hope my guitar had better PU's. Not all PU's like FF's low input impedance. If anybody ever builds a FF or designs a PCB for it, it would be better to put a 100k preset there for Q1 collector resistor (the 33k one there on orig. FF schematics). This helps to find a good value for the system (consisting of PU's & the gain of Q1). I noticed that with 33k the voltage on C of Q1 was -0.9V, and the base voltage was -0.13V. I then changed that 33k to 100k, and now the Vc was -0.5V and Vb -0.10V. Smaller value (10k) didn't work, as the "noise gate" opened just for the peak. The ECG cross-reference list btw. shows ECG102A to be a substitute for 2SA12, so it would also be a good choice. I guess it's the same thing as NTE102A. On DMZ there are data sheets for the NTE102A/103A parts.

-Mikko

Replies:

R.G. >...Not all PU's like FF's low inpu... -- 3/12/1998 7:09 AM
Marrk Thanks for the info, Mikko. I made... -- 3/12/1998 2:48 PM