OBP-3 w/ mid continuously variable boost/cut upgrade for NS2A w/ EMGs

[tedsalt]

I'm getting ready to upgrade my Spector NS2A NT w/ EMG pups by adding an Aggie OBP-3. I know, alot of people have done this, and there are alot of threads out there about this. However, I am going to use the dual 500k linear pot instead of the switch, so I can have a continuously variable spot I can boost or cut. So the preamp will (per Aguilar website) provide +/-18dB of cut and boost at 40Hz, +/- 16dB of cut and boost at a frequency selected between 400Hz and 800Hz and +/- 16dB of treble cut and boost at 6.5 kHz. Anyone else do this? Even to a different bass? I've included my (modded) wiring diagram below. Am I going at this the correct way? As I am going to keep the front of my NS2A body stock with the current 4 holes, I am using (3) stacked pots and a single pot. I'll also be adding a 2 battery box to the back side to power it. I will be sheilding everything as well.

I bought this bass used, and it's loaded w/ EMG P/Js, and the existing volume pots are 25K. I like the tone the pups produce now, so I'm keeping them.

Any feedback is appreciated!

[FunkMetalBass]

What are your three stacked pots? Your setup will be:

Vol/Vol, Mid, Mid Freq, Bass/Treble

I have done this with my Spector w/ EMGs, and I like it.

[tedsalt]

FunkMetalBass - you're probably right. The OBP-3 wiring diagram shows a dual 500k linear taper pot. For some reason I thought that was another stacked pot. This is my first time making any changes to the electronics of any bass, so I'm not very familiar. I do think my soldering skills are up to the job.

I'm looking forward to this setup if I can get all the correct materials together

So would this be the 500K Dual Linear Taper Potentiometer (p/n POT500KDUAL) listed in http://www.futurlec.com/PotRot.shtml ?

That actually makes sense. Dang, I ordered the wrong thing again ...

[tedsalt]

I think I found (and ordered) what I (now) believe is the correct pot (500K dual (gang) linear taper pot) from a place called small bear electronics.

Where to get a 500k pot please ?????

Thanks for pointing that out to me!

[SGD Lutherie]

The bass and treble in the diagram is a stacked concentric pot.

The mid frequency is a dual ganged pot.

You can use separate bass and treble controls, but you need the dual ganged pot for the mid frequency.

[tedsalt]

although my diagram shows 5 pots, the wiring for my OBP-3 SK will actually use 4 -

- an EMG 25K Stacked Volume Pot (A25KX2; not the separate vol pots shown on the diagram)
- a stacked concentric 50K bass/treble pot (boost/cut; included with the OBP-3 SK)
- the 50K pot for mid boost/cut (included with the OBP-3 SK)
- one Alpha dual-gang 500K linear taper pot for selecting the frequency between 400Hz and 800Hz to boost/cut (in place of the included mid switch)

that will fill up all four holes for electronics in my NS2A and allow me the most options sonically using an Aguilar preamp and the EMG pups that came with my bass (which I bought used, so I don't know if they're stock, but I like their tone).