Big Muff Transistor Substitution Question

[bryantbr]

I put together a Big Muff today with spare parts and had everything except the 2N5088 (NPN) transistors.  I do have some 2N5457 and J201 (Fets) and some 2N3906's (PNP).  Can the Fets work in this circuit?

[ninoman123]

FETs, no...PNP maybe...but why go through all that work. Check all of your other wiring before u blame the transistors. Or just...buy new transistors if you think they are screwed up.

[NaBo]

NO!  Don't try putting PNP's in there.  You can only ruin them by doing that, and it won't work.  Nothing good ever comes of reversed polarity.  You "could" switch all polarized components around and make it a positive ground circuit, but theres no point when the 2N3906's you have are low gain, and thus will probably not work -at least not properly- in the muff.

You'll need a high gain NPN... ie: 2N5088 or 2N5089... I prefer 2N5088 in both my muffs... I've made the GGG version and a green russian version so far.  2N5088's and 9's are good to have on hand as an all-around NPN high gain workhorse tranny, you'll use plenty (ex: red ranger and LPB boosters, pulsar, small clone/stone, flanger 301).  Also get a few 2N5087's, the PNP complement, often used in conjunction.

Trust me, a little patience and planning goes a LONG way.... you shall be rewarded with muffly goodness when you get those 2N5088's, I promise  :wink:

[bryantbr]

Thanks fellas.  I'll order the 5088's today.  I didn't actually try to sub anything - I've only soldered up the board and socketed the tranny's so when I get them I'll be good to go.  Thanks again.

[ninoman123]

You "could" switch all polarized components around and make it a positive ground circuit

Thats what I ment by

but why go through all that work.

:oops:  Guess I shoulda been more specific on what the work would be.

[jmasciswannabe]

If you are going shopping you might try to get a few germanium transistors as well. Hopefully you've put some sockets in for the trannys! I recently built the big muff from ggg and after lots of experimenting I found that I REALLY liked the sound when you throw a germanium transistor in there. You get more of an untamed signal.....if that even makes any sense hahah.

[octafish]

I'm a bit late for this and you would have to layout another board but there is a schem for a PNP BMP. I don't know where but I think if you search the archive for "Triangle Big Muff" it should turn up. I think the PNP is like an original USA Mojo thing. I didn't use it, I used Torchy's vero layout. Torchy does the headaching for you.  I liked messing with low gain tranny's in my BMP, 2n2222's etc. Have fun.

[brad]

I'm pretty sure the Swollen Pickle's transistors were low gainers similar to 2N3904s.  Try substituting the tone stack values for the ones in the Swollen Pickle schematic posted in the Layouts Gallery and see what you come up with.

[bryantbr]

Thanks for all the advice.  I did solder in sockets for the transistors so I think I will order some Ge's.  I used the layout from Tonepad and made my own board using PN'P and it turned out great.