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Projects => Diode-Compression Op Amp => Topic started by: Davelectro on May 12, 2011, 01:34:23 AM

Title: Maximum Voltage?
Post by: Davelectro on May 12, 2011, 01:34:23 AM
Hi,

We know that most IC op amps used in stompboxes and guitar preamps can take +/-18V before exploding, right? What about this one? Can I use for example a +/-30V supply if all components by themselves are OK with it?

Thanks in advance.
Title: Re: Maximum Voltage?
Post by: Davelectro on June 18, 2011, 02:24:26 PM
Wow! More than 1,400 views and no response at all?  :icon_eek:

C'mon!  :icon_biggrin:
Title: Re: Maximum Voltage?
Post by: blackcorvo on June 19, 2011, 09:13:48 PM
Depends on what transistors you're using... the transistor's maximun voltage is going to be the extreme max voltage you can use.
Title: Re: Maximum Voltage?
Post by: Davelectro on June 20, 2011, 12:38:19 AM
That makes perfect sense. Thanks blackcorvo!
Title: Re: Maximum Voltage?
Post by: blackcorvo on June 20, 2011, 11:25:11 PM
You're welcome! :3

Also, if you want a bit more of gain, you can try using a Darlington or even a Mosfet in place of the output transistor.
For more compression, you could try a germanium or even a schottky diode instead of the one from the original circuit. I'd also suggest you to change the 6k8 resistor for a trimpot, so you can bias the circuit correctly and match it to whatever power supply you happen to use. Maybe 25k is enough, but if you wanna be sure, use a 100k trimpot (and if you want to be precise, you can always use one of those multi-turn trimpots).

It's a really cool little circuit to mess around with.
Title: Re: Maximum Voltage?
Post by: Joe on August 14, 2011, 11:12:56 AM
Might try MPSA06/MPSA56 for higher voltages.