obp-3 variable mid frequency

catrunes · #1 12-29-2007, 03:19 AM

so i gonna be wiring my bass, which already has the obp-3 installed, with a variable mid frequency control. i got a couple of questions. first, in the wiring diagrams on aguilars website they say to use a dual 500k linear taper pot. would i be able to use a audio taper pot there? and what would the difference be in that situation? also i was gonna set the low mid frequency to 200hz, so i could sweep it from to 200 to 800hz, does anybody think any problems can come out of that?

AppliedStucco · #2 12-29-2007, 07:18 AM

Hi... I'm just gonna try and help you out and, in case I'm wrong, I'm open for correction by anyone who knows better.

First of all, I presume you refer to this guide, last page, bottom Diagram. ("Continuously variable between Mid_low (400 Hz) and Mid_high (800 Hz). Replace the switch with dual 500k linear taper pot: Option #8..."). Right?
http://www.aguilaramp.com/pdf/support_wiring_obp3.pdf

Yes, you would be able to use an audio taper pot there. The difference would be that, as the audio pot is non-linear but logarithmic, you wouldn't get a a nice, smooth mid frequency sweep across the spectrum of frequencies, but instead, as you turn the pot steadily to get to a specific frequency, you would scan constantly faster (or slower) which would make it terribly more difficult to get to a specific frequency you like.

I hope you will be able to understand the difference and I also hope I'm correct...

I'm still thinking about the thing with the 200Hz, though. if I come up with any reason not to try it, i'll inform you...

catrunes · #3 12-29-2007, 01:25 PM

cool thanks man. ya i knew that the log taper pot would do somethin weird. i just cant find any linear taper anywhere, which is bull. any help on that would be nice too.

AppliedStucco · #4 12-29-2007, 03:38 PM

Hi again...

Unfortunately I was able to only come up with this:
POT500KDUAL - 500K Dual Linear Taper Pot - $0.90
http://www.futurlec.com/PotRot.shtml

I hope this might be helpful.

As for the 200Hz thing, I looked at the manual and I don't think there should be any problems... In someway they even propose to you to experiment on that.