Need help . . . building eq

[MHanson]

Hey everyone. I'd like to see about building a very clean/transparent single channel and single band eq. I don't know what the best way to go about this is. I need gain only (6db max), 15-20kHz with variable Q or fixed maybe like an API 550b. I'm guessing I'll need to go from balanced to unbalanced into the circuit and then back again. Any help would be appreciated.
I don't have any ideas on the circuit yet, just the thought that I want to build this. I'm not sure what the best way to achieve this is, so I decided to ask for help. I don't really think I want transformers unless there are some out there that won't saturate and give me a great slew rate to help in the transparency.



Thanks
Michael

 

[MHanson]

Jaakko,

I was thinking about the passive (Pultec) idea. I guess what I'm really looking for are suggestions on which are the cleanest drivers/receivers and opamps for building this. I haven't tried out the various pieces and so I'm looking for comments on the best.

Thanks,
Michael

 

[Svart]

depends on what you want to drive afterwards.

Discrete is the way to go if you absolutely have to positively spend a lot of money and time but get the cleanest sound. OR you could purchase one of the Forssell JFET opamps for your makeup, which i hear are very good. other than that you will spend a good deal of money on a good IC like the OPA627.

In all respects you will need to decide what you want to do/spend and go from there.

there are a lot of good Gyrator designs out there too if the passive EQ doesn't work out.

:thumb: