OBP-3 Variable Mid Wiring

[FunkMetalBass]

Yes, another one of these.

I know I've done this once before, but I have that bass sitting at my parents' house and my head is far too cloudy right now to remember how I did it.



When I use option #8, what do I do with the GRN/BRN, ORG/VIO, and RED/BRN wires? Is the 500k concentric pot an additional pot, or does it replace my mid pot?

[catrunes]

the concentric doesnt replace anything. it allows you to select the frequency you want to cut or boost with the 50k mid pot. you wire the 50k up ho you would in any other of the diagrams, with GRN/BRN, ORG/VIO, RED/BRN to the respective points if looking at the underside of the pot.

[cybersnyder]

I so wish they would have chosen values that you could use with a off the shelf stacked knob.

[FunkMetalBass]

Originally Posted by catrunes

the concentric doesnt replace anything. it allows you to select the frequency you want to cut or boost with the 50k mid pot. you wire the 50k up ho you would in any other of the diagrams, with GRN/BRN, ORG/VIO, RED/BRN to the respective points if looking at the underside of the pot.

So I will need to drill a hole in my bass. Got it. Thank you.

[catrunes]

Originally Posted by cybersnyder

I so wish they would have chosen values that you could use with a off the shelf stacked knob.

seriously.it took me a while to get some of that shizz.

[rojo412]

I bought a bunch of the dual 500k pots and tried this with a relatively disappointing result.
(PM me if you want one, though they only fit on a plate unless you mod like I did).

It didn't "Sweep" like the East or EMG preamps did, it kind of sounded like 2 different tones, not infinite. Was more like a "TONE" pot that didn't sound right.

Personally, because of that fact, I abandoned my use of this preamp. It's not bad with the switch, but the pot doesn't quite work so hot.

And also, the "500k Dual" isn't a stacked pot. It's a dual pot, but only 1 shaft (like a pan pot).

[FunkMetalBass]

**** I'm retarded. I knew my stacked pot looked out of place.

There's a reason I don't solder when I'm at home sick from work.

[cybersnyder]

Originally Posted by rojo412

I bought a bunch of the dual 500k pots and tried this with a relatively disappointing result.
(PM me if you want one, though they only fit on a plate unless you mod like I did).

It didn't "Sweep" like the East or EMG preamps did, it kind of sounded like 2 different tones, not infinite. Was more like a "TONE" pot that didn't sound right.

Personally, because of that fact, I abandoned my use of this preamp. It's not bad with the switch, but the pot doesn't quite work so hot.

And also, the "500k Dual" isn't a stacked pot. It's a dual pot, but only 1 shaft (like a pan pot).

Did you use a 500K linear or audio/log pot?

[rojo412]

http://futurlec.com/Potentiometers/POT500KDUAL.shtml

It's linear. Sounds like FunkMetalBass may be trying them out, so let's see how his goes.

But I first tried with the capacitors (figure #7) and it sounded like a tone pot... then I tried a different pot completely, just the wires... didn't really sound much different.

[FunkMetalBass]

A 400Hz sweep isn't going to make much of a difference. If it were possible to use capacitors and sweep between 400Hz and 1.5kHz, it'd be a more noticeable difference.

[rojo412]

You can add the caps to go BELOW 400 (I had caps set up to do less than 180)... eh...

[ErnieD]

fellers but I just posted a very long new thread here titled "What Happened" concerning a OBP-3 pre in my MTD KZ5.

Is there schematics available to say how this preamp may function if wired differently? If you go read my long thread on how a repair shop totally changed the tone of my MTD; any suggestions would be much appreciated. Otherwise, I'm looking for another repair shop but they still might want/need the schemes. Thanks all for any suggestions (over there), and carry on now.

[rojo412]

Any moves on the Mid Sweep install?