Neve EZ1290 build (1073 with NO EQ). Where would I put the EQ? Are there kits for just the EQ?

[777funk]

I built this preamp in 2014 or so and enjoy it. I put an 1176 (just the unbalanced middle section of the compressor - no transformers) in the middle of the Neve circuit and it works well for tracking. BUT... I am finding I'd like to Hi Pass most sources before they hit the 1176 compressor.

So that means I either need to add a simple HPF switch somewhere in the circuit or build the actual 1073 EQ. I doubt I'll ever use most of the Neve EQ features other than the HPF. If I could just add a toggle switch to roll off below 100Hz or 150Hz I'd be plenty happy with that.

So two questions:
1. Is there a place to find a board for the 1073 EQ (only)?

2. Alternatively, where would be a suggested place to thin this thing out if I were to simply use a smaller bypass cap to couple between one of the first couple transistor stages? I'm thinking the tantalum cap circled. This thing must pass just about everything going through it at 10uF. Maybe something more like 0.22uF, 0.47uF, 1uF, 5uF, 10uF on a rotary 5 way switch would be a good way to HPF this thing?

 

[777funk]

I decided to keep it simple and instead of a rotary I just put a single toggle switch bringing it back to full range (10uF tantalum). I experimented with a 0.1uF (small difference), 0.022uF (removes very low rumbling, but not really enough to HP a vocal), 0.01uF (getting there), and 0.0068uF. I decided that this is nice and crisp and keeps the compressor after the pre doing what it should (compressing the keeper signal, not the full range for which most of the lows will be EQ'd out later).

I also tried 0.001 and 0.0047uF and both of these were too thin. The 0.0068 is right where I want it. I wouldn't mind trying something in between 0.0068 and 0.01uF for good measure but I don't think I have anything on hand. I will track with the 0.0068uF and adjust if it seems too thin. I'm thinking it's perfect.

EDIT: I suppose I could have put a 0.001 or two in parallel with my 0.0068uF But there comes a point where time counts and you have to move on.

 

[Dave_Eropkin]

I implemented a switched hi-pass filter (100 Hz) where the trim pot usually is... Since I had no trim, I used DOA style pins and printed a small circuit that has a Panasonic low signal relay to switch the filter in and out...