Passive EQ

[ethrandil]

Hey how,

I've designed a (nearly) passive EQ with a very simple design. As this is my first (adaption of a) Design, I still have some questions.

Is it correct that way? (R6+R7, ... are Pots; C4... can be changed)
Is the input-Impedance 10k? And aint' that too little? And the output?
How can I determine which Opamp would be best for this circuit?

mfg
- eth

 

[jan.didden]

Hey how,

I've designed a (nearly) passive EQ with a very simple design. As this is my first (adaption of a) Design, I still have some questions.

Is it correct that way? (R6+R7, ... are Pots; C4... can be changed)
Is the input-Impedance 10k? And aint' that too little? And the output?
How can I determine which Opamp would be best for this circuit?

mfg
- eth

... what circuit..?

Jan Didden

 

[Minion]

Well if there is an opamp then it isn"t a Passive EQ....But since you didn"t post a Schematic it would be very hard to help you....

I have a design that uses a Single OPamp and can be adapted for as Many EQ Bands that you want, The curcuit presently has 3 Bands (High,Mid,Low) but many more bands can be added.....Let me know if you want to look at it.....


Cheers

 

[ethrandil]

Yeah, I was under moderation since this was my first post and so i couldnt add the circuit when i noticed my fault. So here it is:

An externally hosted image should be here but it was not working when we last tested it.

 

[JonnySwitchblade]

Ethrandil it looks like a fixed EQ to me so I would say no, R6 and R7 are not pots based on that schematic.

C4 can of course be changed but will alter the set frequency point.
EQ/tone circuits with inductors aren't incredibly common but in my opinion yield better results than resistors which seem to "deaden" the signal to attain the desired results.

If you want to know which op amp will sound best, that's easy. Install a DIP-8 socket/solder tail and just pop in different op amps until you're happiest. The 604 or 532 will perform best though. That's just my opinion however.