A couple dumb questions about the Corduroy fuzz (input transistor swap?)

[xefned]

I've always read that you can sub MPSA18 for the 2N5089, but that has an hFE of around 8-900 vs. 6-700 for the 2N5089. (I don't have any 2N5089, but I have a bunch o' MPSA18's.)

If I used the MPSA18 (800hFE), would that change anything for the worse?
Or should I just add some 2N5089's to my next parts order?

Schematic fragment added for reference.


I

 

[xefned]

Another Q:
If I plan to run it at 18v, would I have to bias the FETs differently?

 

[xefned]

If I used the MPSA18 (800hFE), would that change anything for the worse?
Or should I just add some 2N5089's to my next parts order?

For future travelers … what did I do?

I measured a bunch of 2n5088 and found 2 that measured over 600 hFE. Close enough for rock 'n roll.

 

[Chuck D. Bones]

MPSA18 is a good sub. Like most pedal circuits, HFE is not critical in this circuit.

DO NOT run this on 18V or you will blow the LM386.

 

[xefned]

DO NOT run this on 18V or you will blow the LM386.

THANKS for this advice!!
I'm probably confusing it for a different pedal I saw run at 18v. I watch lot of videos and don't take proper notes.

 

[Chuck D. Bones]

Gotta take the YaoTaob stuff with a grain of salt. Andy Martin demos I trust. Most of the rest is meh at best.

 

[HamishR]

See those weren't dumb questions after all. If you don't know - ask. Not dumb - smart.

 

[xefned]

Andy Martin demos I trust. Most of the rest is meh at best.

I think I was confusing it for the Drive 55 pedal. I watched Andy's demo of it the same day I researched the Corduroy.

 

[xefned]

NOW I REMEMBER WHAT PEDAL I WAS THINKING OF!
Sorry for shouting.

It's the Golden Falk Overdrive. It really does sound better at 18v, doesn't it?

So if you set the 3 trimpots to 5.5v, 5.8v, & 4.6v, and then you feed it 18v, does that screw up your bias points?

I'm assuming not, because that would also affect the retail unit and they don't expect users to set trimpots when they want to switch to 18v, eh?