I only have 1 mpf102 and I need one more for a wah, whats a good substitution short of pulling it out of another pedal while I order more?
What's it being used for?
Quote from: jimilee on March 28, 2014, 05:07:40 PM
Quote from: midwayfair on March 28, 2014, 05:06:58 PM
What's it being used for?
Wah pedal
That's a type of effect, not a specific circuit or function.
What's it being used for in the wah pedal? Are you building the Weener and using it for Q3?
Quote from: midwayfair on March 28, 2014, 05:10:42 PM
Quote from: jimilee on March 28, 2014, 05:07:40 PM
Quote from: midwayfair on March 28, 2014, 05:06:58 PM
What's it being used for?
Wah pedal
That's a type of effect, not a specific circuit or function. What's it being used for in the wah pedal? Are you building the Weener and using it for Q3?
Sorry Jon it's the MoWah fron GPCB the mpf102s act as buffers in this particular application.
Come on, Jimi, post a schematic. Don't make us google for it, or worse need to sign in to Barry's frigging site to view their build documents. ::) http://www.guitarpcb.com/PDF%20Files/MoWah%20v3.pdf
Anyway, when you're considering a FET for a buffer, you're interested in the |Vp|; this is the input voltage before the FET distorts.
2N5458 and 2N3819 both have high Vp. 2N5952 is probably the next best bet.
2N5457 is "adequate," and I'm willing to bet you have a couple in your parts bin, but it's only 1.5V of headroom. Put it in Q1 and use the MPF102 you have for the output buffer if you don't want to order some replacements.
Thanks jon, next time I will post the schematic. Sorry about the hassle sir, I should know better. I'm ordering more, I was just looking for something in the meantime.
Quote from: jimilee on March 28, 2014, 06:12:15 PM
I'm ordering more, I was just looking for something in the meantime.
In that case, you can use any FET. It doesn't matter if it's just a buffer, but realize that stuff used in overdrives will distort if you push them.