Wiring Aguilar pickups and preamp

[AsmundKleivenes]

22 years ago I purchased an Aguilar OBP-1 preamp to replace the one in my Yamaha TRB5, but neither me nor three different guitar workshops have managed to get that combination to work a 100 %.

This month I decided to buy a pair of Aguilar DCB-G4 pickups, assuming that Aguilar works best with Aguilar.

Aguilar, however, offers various wiring diagrams for the preamp, but only one for the pickups. The last week I have therefore corresponded with Aguilar through several e-mails, asking them for instructions on how to connect the electronics.

Unfortunately I didn't get any wiser, so can anyone here. Can anyone here instruct me (draw the lines) on how to wire the Aguilar DCB-G4 pickups, the Aguilar OBP-1, one volume control, one blend control, one bass control and one treble control?

It would make my day, and you should apply for a job as a technician at Aguilar (Korg).

 

[LoveThatBass]

Can you state what is not working properly? You did buy a legitimate blend pot and not a dual concentric, right? You could use a Dual Concentric Pot for independent control of each pickups volumes and then controlled by the Volume shown on the ODP-1 diagram (as a Master Volume) but it would be wired slightly different (each section as a separate volume. And for the Blend AND Volume you did use 250K Audio pots right? And 25K Linear pots for the Treble and Bass controls to the Preamp?
For one, the pickup’s connect to the Blend pot.

White wire of neck pickup to the center wiper wire lug (as labelled on the OBP-1 Wiring diagram) of the end pot portion (closest to you looking from back side)

White wire for the Bridge pickup to the center wiper lug (as labelled on the OBP-1 Wiring diagram) of the portion of the blend pot closest to the wood in the cavity.

Both pickup’s black wires and gray wires connect to the sleeve of the Stereo control jack.

The pickup’s black is the common wire for the pickup’s coil and the Gray is to shield the pickup’s metal bracket or frame to ground to lower noise.

If you did use a Blend pot and connected the pickups to the correct lugs then you might try removing the ground wire from the Blend pot that goes to the common ground on the output jack’s sleeve.

I have to admit it seems weird to me they recommend no ground for the Bass control to the preamp but they are the designer. Usually controls have ground like the treble control. Does the Bass control work normally?

 

[fig]

I consolidated your wiring diagrams into one. It's electrically the same as you provided.:

I think I see why (possibly) the technicians couldn't get it to work. Look at the Blend pot in the diagram. See the arrows and stars pointing to wiring next to it? Now look at the very last note (with the star) they refer to.

If the techs tried installing an MN taper (a popular taper) blend pot, the wiring as you currently see it connected won't work. The note specifically says if using MN, then some wiring as to be reversed. Aguilar had another taper type of blend in mind when they made this diagram, which probably would work.

Just a possibility.

Like @LoveThatBass asked, what specifically isn't working properly?

Anyway, here's your diagram with the lines drawn in. Hope it's helpful.

 

[LoveThatBass]

fig, very nice job on the wiring diagram. I am not very familiar with MN taper. So I guess they are opposite in taper from audio and linear taper? Thus reason to swap pickups connection to the blend pot?

 

[fig]

Thus reason to swap pickups connection to the blend pot?

There are two versions of the blend pot from Aguilar.

The older version blend pot was discontinued in 2015 and this is the version used in our diagrams.

In the same year, the newer version came out needing a different connection scheme. The newer version matches how MN pots are wired, hence, the note they added at the bottom of our diagrams.

I remember reading that years ago and found a note on the Best Bass Gear site that mentions it.:

Edit: Forgot to mention, the note is from an AC taper blend pot, not MN taper. Leads me to believe your diagram uses an AC taper. The note I posted is in this link.:

Noble 250k Blend Potentiometer A/C Taper as used in Nordstrand Preamps - Best Bass Gear

 

[AsmundKleivenes]

WOW! Thanks for helping!! This is exactly what I need.

The first workshop used the original blend pot, but they didn't get it to balance the two pickups right. The next two workshops tried two volumes instead of volume and blend, but the controls either had to be completely up or completely down, or they would only work from mid volume and up.

The main thing that caused difficulties here, was that Yamaha's tech support wasn't able to tell me the value of the volume control on the original preamp, so we never really figured out the value the Yamaha pickups needed.

But that's not an issue here, as I have already removed the Yamaha pickups from the bass and are now putting in the new Aguilars. I'll be using the values stated in the diagrams, and am now going to wire everything based on your tips and – not at least – fig's diagram.

I'm excited – and will keep you posted!

 

[AsmundKleivenes]

Update: Using the original spec, the blend only distributed sound to the bridge pickup. With the new spec I got sound on both pickups, but only one at a time. Total silence with the blend in middle position.

So I went for two volume controls instead, and the sound is fantastic!

Thanks again for helping out!