Has anyone tried alternative FETs in dual-minibooster circuits, specifically the BSIAB? I'm trying to reduce intermod on an updated BSIAB, and I wondered if the 2N5457 had better tone. I realize there's less gain, and that's OK with me.
I'm a couple J201's short of having todays BSIAB build...it's working with some MPF102's, to fiil the gap, but upon swapping, I know the last two J201's will light it up more.
Why not try some different Jfet types for a while...I would...I've had good 'Jfet' results using J201's, and many circuits call for them.
J202's are a little higher gain I understand.
Gotta get smore Jfets...
Ed, What I've been doing is Socketing my Bias resistor's and Tone cap's along with the Transistor's, I've been finding different combination's that sound better for what I want to hear out of my guitars, I've found on the boosters I've built so for, I like a little less gain, it really make's the signal cleaner for me and I still get the boost I want.
JD
Hi Ed,
Quote from: Ed G.Has anyone tried alternative FETs in dual-minibooster circuits, specifically the BSIAB? I'm trying to reduce intermod on an updated BSIAB, and I wondered if the 2N5457 had better tone. I realize there's less gain, and that's OK with me.
I have used 2N5457 in a minibooster they sound great. :D I suspect the top FET can be replaced with a Mosfet like a bs170 or 2N7000 with no change in sound. The bottom FET determines the sound. The top transistor is really a current source so just about any n channel transistor should work. It's used to maximize the gain of the bottom FET.
Regards,
Will
Quote from: willHi Ed,
I have used 2N5457 in a minibooster they sound great. :D I suspect the top FET can be replaced with a Mosfet like a bs170 or 2N7000 with no change in sound. The bottom FET determines the sound. The top transistor is really a current source so just about any n channel transistor should work. It's used to maximize the gain of the bottom FET.
Regards,
Will
The main thing I'm wondering about is getting a 'tighter' sound, kind of clearer, when riffing on the neck pickup, it sounds a little murky. I was considering raising the source resistor on the bottom device and using a bypass cap to accentuate the higher frequencies, but havent' gotten around to it yet. I can't get any 2N5457's around here, I have to order some, so that's why I ask. Otherwise, I'd just pop in it, the circuit is on a breadboard right now.
I've tried the mpf's on 2 project's, just got some 2n5457's in but have not used them, how much of a tone differation do you hear in them ED ?
JD
I believe the 57's should be higher in gain than the mpf102's, but less than the J201's.
I know I could tighten up the sound if I ran the pedal at 18V, but I like the convenience of 9V, so I'm going to keep plugging away at it.
Hi Ed, the 5457's might just be what you need, they are clearer, almost a little bright, but that might just be lack of gain.
Jered
I compared a 2n5457 with a mpf102 side by side(dpdt switch for instant change) in a peppermill gainstage, and to my ears the gain and volume is quite even, with the mpf102 sounding a tad brighter. Same results using bf245's (they sound similar to the 2n5457).
I don't know how would they behave in a miniboost stage, gotta try that one on the board.
Hope this helps :)