Replacement for MPSA-18

[tatems]

What would be a good replacement for an MPSA-18? I can't seem to find them in any of the shops in my area.

[petemoore]

2N5089
 I think it's functionally exactly the same thing....high gain/low noise transistor

[tatems]

would a 2N5088 be ok? I can't get the 2N5089 easily?

[Dragonfly]

in addition to the 2n5089 (which has a lower hfe..typically about 500, compared to the mpsa18's 700 or so)...try a NTE47....

andy

[sovtek50]

BC550C is also an alternative.

[cd]

Any of the suggestions above will work, just watch the pinout, since it may be different from the MPSA18.  A 2N5210 will also work.  Depending on your circuit, a 2N2222 will work.  If the circuit actually uses all the gain in the transistor (like a twin-t wah for example) you need a high gain transistor.  If it's just an emitter follower (like the output buffer in a Tubescreamer) pretty much ANY transistor will work since there's no gain involved (just buffering).

[zachary vex]

a 2n5088 would be my next choice, based on parts i stock.

[AmpliFuzz]

On a similar note, what's a good available replacement for the MPSA14 in the Zakk Wylde overdrive? Both shops here carried only the MPSA13. It works and sounds pretty great but volume is slightly below unity at full-tilt.

[cd]

On a similar note, what's a good available replacement for the MPSA14 in the Zakk Wylde overdrive? Both shops here carried only the MPSA13. It works and sounds pretty great but volume is slightly below unity at full-tilt.

That's exactly what I was describing above.  You've got a problem with the rest of the circuit is gain is below unity with the Level cranked - the first transistor is an emitter follower (buffer) so it provides no gain at all.  You can use any low noise, high gain transistor.