An Active MM/J wiring connundrum

[thebass905]

Hey TB, I recently purchased a Brubaker Brute JJX 5 String bass in Olympic white... (Drooling yet?) The bass has been heavily routed from J/J to MM/MM and finally a J was stuck in the neck, and an MM in the bridge. It has these current Specs:

Lakland American MM/J pickups

EMG 3 Band Pre Amp with sweepable mids

Vol/Vol controls

Front/Dual/Rear Coil Tap switch for the MM pickup

As wonderful as that sounds, there are some issues. The Bridge pickup is about 5Xs as loud as the neck.... so I brought it to a local tech, and while he may not have been the most qualified, he reasoned that the volume drop off was due to the fact that the MM in the bridge ran through the battery, and the Neck P'u didn't.....

Makes some sense I guess, but can anyone tell me a bit about Lakland Pickups (I though their pickups were passive with active preamps?) or a possible way to resolve this issue? He wanted to charge me a ton to do a full pickup change, which makes no sense. I'll post pictures when I get the chance, and happy thanksgiving to you (hopefully TB offers a great reprieve from the inlaws... unless of course you like them!)

 

[line6man]

The bridge pickup is probably louder, because you are mixing active and passive pickups without buffering, so the lower output impedance of the active pickup is basically shorting out the passive pickup.

If you want to mix actives and passives, you need to buffer the passive pickup, to get its output impedance down to match with the active pickup.

 

[two fingers]

To clarify, is that your goal to keep them that way? You want the J passive and the MM active? Or are you asking how to incorporate the J into the active circuit? Those are two completely different solutions (either of which line6man can clear up for you with his eyes closed).

 

[mmbongo]

Both of those pickups are passive. Lakland does not make active pickups, so neither 'runs through the battery'.

What is the volume difference when the MM is switched to single coil?

 

[thebass905]

To clarify, is that your goal to keep them that way? You want the J passive and the MM active? Or are you asking how to incorporate the J into the active circuit? Those are two completely different solutions (either of which line6man can clear up for you with his eyes closed).

I assumed Lakland didn't make actives... I just want both of them to be the same darn reasonable volume. don't care how!

 

[thebass905]

Both of those pickups are passive. Lakland does not make active pickups, so neither 'runs through the battery'.

What is the volume difference when the MM is switched to single coil?

The volume actually increases vvveeerrryyy slightly as the change from hum canceling to single coil in the bridge is switched. That isn't an issue at all.

 

[line6man]

Both of those pickups are passive. Lakland does not make active pickups, so neither 'runs through the battery'.

What is the volume difference when the MM is switched to single coil?

In that case, impedance mismatches may still contribute, if the MM pickup is parallel-wired, as MM pickups tend to have low output impedances. Either way, however, they are generally rather hot pickups, so it may simply be that one pickup is hotter than the other.

You might consider a trimmer pot in series with the MM pickup, to adjust its volume.