Feeler: Nite EQ

[JeromeMason]

For those not familiar with it, it's basically the Maag EQ4 in stereo rack form, but it's the original, what the EQ4 was modeled on. I've watched at least 6 different interviews with some massive heavy hitters and almost all in a row mentioned this EQ on their buss. Even if you've got your fav EQ on the buss, you're basically getting two EQ4's in rack form. The minimum on cases is 10, and the minimum on PCB's is 60. So it'll take a few people wanting this to get it going, but it's worth a shot.

I'd like to revive this EQ as it has been an industry favorite since it's inception and it's a fabulous EQ, it really needs to be back in the active project form.

Is anyone interested in going along with me in reviving this project?

 

[peterc]

PM sent

 

[JeromeMason]

Fixed it, thanks Peter!

 

[frazzman]

I think if you want do this, the layout needs to be modified to make it worthwhile. Getting the frequency response flat in the original is a nightmare, even with center ident pots - the build is overly sensitive to pot tolerances. It would be good to at least change the footprint in the board for the 5k6 series resistors to a trimmer so that adjustments can be made on each band to get a flat response with pot centred. Above that a reengineer of the design using derived bands instead would be another improvement (as pointed out by Harpo on the previous thread).

 

[frazzman]

Also... Rethinking back to my build.... The other side effect of the original design is that each freq band needs to be exactly 2 octaves apart, which is near impossible given the tolerance of capacitors. As a result you end with lumps and bumps in the frequency response even if you tweaked 5k6 series resistors for centre position