Building An Equalizer
 

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. :smash:

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.]

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

Little old, but complete....

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.

Many thanks for the replies everyone.

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