Can I put gain control here?

[zener]

I found this 3 band single opamp eq


I'm planning to hook it up as a preamp to a power amp and wondering if I can put a gain control here.

There's also a similar eq in page 9 of TL082 datasheet. http://www.national.com/ds/TL/TL082.pdf I would love to put a gain control in both, if possible.

Thanks for any help.

[David]

Zener:

Use a dual op-amp.  One half is for your EQ.  Build a preamp with the other half.  You can implement your gain control with a fixed resistor, capacitor and pot in the feedback loop.

[zener]

Zener:

Use a dual op-amp.  One half is for your EQ.  Build a preamp with the other half.  You can implement your gain control with a fixed resistor, capacitor and pot in the feedback loop.

Is this a complete one: (of course, minus the gain control)


So I'll just put a variable resistor between pin1 and pin2 and a cap in parallel, is that right?

Thanks :wink:

[petemoore]

More than 60 Million years???
 One cave guy found a string.
the other cave guy found a board.
It's all history after that...now there are fully grown men all over tha planet shaking strings on boards, waving the boards around, and going BBwwwwahhhh [sound of guitar power chord 'A'].

[David]

That one's a buffer (unity gain).  Look for RDV's posting on his "Super Simple Preamp".  He's got a schematic there that nails it.  That would be your "front half".  Your EQ is the "back half".  Easily implemented with a NE5532, TL072, etc.