Building An Equalizer

[bezeek]

Hi everyone,

I've got plans to build my own EQ, and I've been looking around at pre-drawn schematics, but being no electrical engineer, I've got a whole myriad of small questions.

First, I should explain what I'm hoping to achieve:
> 10 bands per ch. for 2 channels.
> Master gain/attenuation for both channels at once.
> Knob-style pots to conserve space.
> A final design fitting within a 1U 19" rack enclosure.
> As little added noise as possible.

Here is one of the schematics I've been looking at.

To the best of my knowledge, those op-amps will do just fine, but that opinion is biased towards the fact that I wouldn't know what to do with the circuit to use different ones.

For the questions though, these are mostly small, but I would really appreciate any help determining the following:
> How to double up to cover both channels separately.
> What considerations I should take regarding the power supply.
> If anyone happens to have a spare enclosure (any kind) they could sell me...
> And finally, if any of that design would remain in tact should I wish to use different op-amps.

Of course, I can give more details upon request, but that's the basics of it I think.

Thanks!
- Brian Ziemek

[Edit: Posted the wrong schematic.]

[Nordic]

http://www.swtpc.com/mholley/Popular...PE_May1974.htm

Little old, but complete....

[radtech]

Here's a page with some other EQ designs, parametric and graphic using gyrators, you might want to have a look at those.

http://www.ethanwiner.com/spectrum.html

As for opamp type, you'll probably not want to use 741's. There would be little if any change in the circuit when using other opamps. 5534's would probably be a good choice.

To make 2 channels you'd simply duplicate the equalizer part, and use one power supply to power both.

[acenovelty]

http://sound.westhost.com/project75.htm

[bezeek]

Many thanks for the replies everyone.

Originally posted by acenovelty
http://sound.westhost.com/project75.htm

I've got two questions about this deisgn. One, could someone please explain what each connector represents, and two, how would I implement a 50k pot to control gain/attenuation on the input signal?

- Brian Ziemek