Help Needed - Bass Mods Preamp Installation

[BlountEdge]

Hi All,

I’m looking for help with installing a Bass Mods preamp (and pickups) in one of my Atelier Z Jazz basses. The bass currently has stock Atelier pickups and a 3 band Atelier preamp. The pickups are great, but the preamp must go.

In looking for a replacement, I bought a used Bass Mods preamp (pre-wired to a control plate), a set of Bass Mods jazz bass pickups and a Switchcraft input jack.

I’m experienced with soldering and installing pickups in passive basses, but I haven’t installed preamps or added pickups to existing preamps.

I emailed Bass Mods about 2 weeks ago for a wiring diagram (or guidance), but they haven’t responded, so I’m hoping that someone here can help me.

As you can see in my pics, the control layout shows 2 concentric knobs and 2 standard knobs. There are also 2 toggle switches. The store that sold the preamp listed it as a Bass Mods MC3, but the MC3 preamps on Bass Mods’ website show a different control plate layout. As a result, I don’t truly know what the model is. The store has no additional info.

If anyone can help, I need to know the following:

1. To which pots should I connect the pickup wires?
2. Where should I connect the wires from a battery clip? (not pictured)
3. How do I connect everything to the input jack?

I can post additional pics or angles, if needed.

Thanks in advance!

 

[Crater]

DISCLAIMER: these are all educated guesses based on my knowledge/experience.

That's someone's custom "everything but the kitchen sink" setup, I don't think BassMods made that control plate, they just make the amp module. I believe these are the controls based on this layout:

The MN250K pot is a blend pot, so that's where the pickups are connected. The concentric controls at the wide end appear to be a master volume and passive tone. The toggle switch next to it may be a tone cap select switch; whatever it is, it's not an active/passive switch. Concentric controls at the skinny end of the control plate appear to be the bass/treble EQ controls for the preamp. That leaves the single knob as a midrange control. Not sure what the second toggle does either, but it's also not an active/passive switch, might be a mid shift or scoop setting, who knows?

Where should I connect the wires from a battery clip?

The red wire in pic #3 appears to be the positive battery lead. The negative lead from the battery clip would be connected to the black wire in pic #4 and the other end soldered to the ring terminal on the output jack.

How do I connect everything to the input jack?

Pic #4: White wire is output, goes to the tip terminal on the output jack; orange wire is apparently the ground, it would be soldered to the sleeve terminal on the output jack. Again. the black wire (battery negative) again goes to the ring terminal.

Good luck!

 

[BlountEdge]

Hi Crater,
Thanks so much for your detailed response. I also appreciate that you responded so quickly. I will try to move forward with my installation, based on your guesses.

 

[billdylan]

Hey there Buddy..Don't expect any help from Bass mods...There is no follow up support..I bought a few of their older style Pre Amps and received no reply to multiple emails asking for wiring diagrams and general help...they sure are not a Bartolini or Aguilar when it comes to support ..I would look else where for future Pre Amps..
..Hopefully you can find some bits to help you on Google..Good luck..