Push/Pull off switch for OBP 1

gimmeagig · #1 11-24-2012, 01:06 PM

I have the OBP 1 18V preamp in my Modulus J Bass and I'm wondering what it would take to replace one of the pots with a push /pull option to be able to run active or passive.
My Sadowsky preamps have that and I really like that feature.
Can you guys tell me if that is doable and what parts I might need.
The Sadowsky pre has the switch on the Bass pot and I have a Noll preamp where it is on the volume pot.Does it matter where I put it?

line6man · #2 11-24-2012, 01:21 PM

250k or 500k push/pull, if you put in on a volume or tone knob. I believe the bass and treble pots are 25k for the OBP1, if you want to put a push/pull on one of them.

gimmeagig · #3 11-24-2012, 02:27 PM

I'm going to have a local repair guy do that for me.Is there a schematic for that modification floating around somewhere on the web that I could print out for him?

line6man · #4 11-24-2012, 02:47 PM

He should know how to do this already.

gimmeagig · #5 11-24-2012, 05:35 PM

Thanks, Lineman.I'm sure you're right, my guy has repaired a couple of amps for me which seems a lot harder than this.I'll send him the diagram anyway.