+9V/-9V bipolar Big Muff

[Psychopath]

How I make Big Muff work on bipolar power supply +/- 9V?

[dwmorrin]

Do you mean hooking up to a bipolar +/-9V power supply, or changing the circuit to bipolar?

In the first case, just use the +9 and ground/common connections of the power supply and leave the -9 alone.

In the second, you'll be connecting +9 the same, but the emitter resistors and the bias-to-ground resistors will be going to -9 instead of ground.
Most of the voltages will now be negative, so you'll have to reverse all the electrolytic caps.
The passive parts (volume controls, tone network) still get returned to ground.
Rewrite the schematic and test out the idea on a breadboard.

[R.G.]

Or yet again, that you have a +/- 9V supply, and you just want it to work on that. This variation depends on the power supply, but most of them will let you just hook to +9 and ground, ignoring -9V.

It all depends on what you have and where you're trying to go.

[doctortropico]

changing the circuit to bipolar?

Why would one want to do this? In other words: how would/could this alter the sound?

[gtudoran]

Much more headroom ... and i guess less distortion and more volume (not necessarily) ... from the tonal point of view... i think that the signal would be more clear... buy i guess that with a Big Muff that would be totally impractical and useless.


Best regards,
Gabriel Tudoran
Analog Sound

[Psychopath]

This could apply to a bee baa or foxx tone machine.  It's getting housed with other bipolar effects so the power is available.

[R.G.]

OK. One step forward.

It then depends on the details of that "bipolar power supply" that's available. If it's a strong +9V and the +/- voltages are quasi-independent, the simple thing to do is to just hook the effect to +9V and ground.

I say this because many "bipolar" power supplies have quite weak, special-case negative supplies.

Once again, details matter.

[Psychopath]

the power will be robust.  center tapped AC transformer.

Most of the voltages will now be negative, so you'll have to reverse all the electrolytic caps.
The passive parts (volume controls, tone network) still get returned to ground.

this remains accurate?

thanks

[dwmorrin]

Rewrite the schematic and test out the idea on a breadboard.

Try it on a breadboard and see for yourself. Build the first stage on a breadboard without caps - just transistor and the resistors to make it work.  Measure the voltages at the transistor terminals, and then put the coupling caps the correct way based on what the meter says.
I put it in a simulator, and the transistor terminals were all at negative voltages.

Yes, the passive stuff can be returned to ground, but please check this on breadboard first.

I think experiments like this are great for learning, but as others have pointed out, this may not achieve much for the big muff.