MPSA18 transistor substitute for Tripple Fuzz?

[vseriesamps]

Hey all

I wanted to build the Tripple Fuzz after the recent post lauding it, but I don't have an MPSA18 transistor on hand. Could I sub either a 2N3904 or a MPS2222A in this effect? The specs aren't identical, but they're *pretty* close . . .

(and what's the thing to look out for when subbing transistors anyway?)

Thanks always to everybody for input. Killer forum.

K

[puretube]

look for low noise, hi gain...
2N5088;
in Europe: BC550 C or B;

[jimbob]

WHat can i do about getting around the 1 m trim? I dont have one.

[puretube]

WHat can i do about getting around the 1 m trim? I dont have one.

re-read the relating thread, or buy one...

[Tim Escobedo]

The 2N3904 or a MPS2222A might not cut it. I think it sounded best with a high gain transistor. Worth a try, though.

Matching of the NPN/PNP pair didn't seem terribly critical. I found that a 2N5087/MPSA18 pair also sounded quite good.

Also, the 1M trimmer isn't needed. I replaced it with a 500k-1M resistor connecting collectors to bases of the NPN/PNP pair. In fact, it seems if the pair are high gain transistors, you may hardly need any resistor there.

[jimbob]

Great! Thanks Tim..Thats what i needed.

[Ge_Whiz]

Tim - seems that whenever you update your designs, people want to build the 'classic' version... :lol:

I used a generic transistor for Q1, gain of 700.

[petemoore]

You can make a darlington...see ROG Bazz Fuss...
 I don't really know but low noise-er's mgiht be preferable when doing so?

[b_rogers]

i just found a few mpsa18 in a assorted pack of trannies at Radio Shack.

whenever i go in i shake them around and see whats in 'em.

so if you dont have any check at the shack in the NPN switching transistor assortment packs.


Brent