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Vintage threads from the first ten years

FET help, please

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5/26/1999 7:14 PM
John C.	FET help, please I need some equivalencies for the J201 Fet(brand:TEMI) A few if possible, please again, as I just can't find any where I live. I really "need" it, as the effect is almost finished except for those two J201 I can't find. Thanks a lot. JohnC

5/27/1999 2:51 AM
aron	NTE458, NTE457, I would imagine ECG457, ECG458, 2N5457. Check the pinouts, they may be different but useable if you used sockets. Order the J201s from www.techamerica.com or future Future Work: (800) 655-0006 Aron

5/27/1999 6:24 AM
John C.	Thank you again, Aron. A lot. How could I recognize, reading a transistor data, one that has more or less gain? JonhC

5/27/1999 11:51 AM
aron	I think R.G. has some sort of FET testing jig on his web site: http://www.eden.com/~keen/ and Jack Orman's FET Muff article on AMZ talks about biasing the FET: http://www.muzique.com/amz/ Basically, the higher the drain resistor needed, the more output the FET has. Aron

5/27/1999 11:52 AM
aron	I forgot, I don't think you can find out if a FET has more output that another except very generally. In my experience, FETs are all over the place. You just have to plug them in and see. Aron

5/27/1999 9:06 PM
John C.	So, I did the correct thing in my (SB III) pedal. I soldered sockets in, so I may try in the future some other FETs if I find any. Those 2N's you told me in another post work perfectly alright, anyway. Thanks again.

5/28/1999 12:49 AM

John,

As noted in the schematic, if you clip the 22K resistor going to ground in the tone control circuit, you get a totally different sound from the standard big muff tone control.

I like this sound much better...

You want JFETs that are smoking so you get some distortion from the MiniBooster circuit. Another mod is to put a 100K trimmer before the 1Meg resistor of the MiniBooster. Wire the trimmer as a volume control (signal to outer lug), the other outer lug to ground and the middle lug to the MiniBooster.

Use this to "tune" the amount of drive being fed into the MiniBooster when the drive is max'ed out.

The MiniBooster sounds so good. Thanks Jack!

Aron

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