Something wrong with this preamp?

[Luke Warm Water]

Hey All,

I welcome your thoughts.

I recently replaced a stock preamp in a Fender MIM Deluxe PJ with a Bart preamp that I bought from a TB'r. I also replaced the bridge pickup with a Nord NP4. The P-pickups are still stock at this point. But before I proceed, I've run into a weird issue - When the pickups are equally blended (which is where I usually have them set), it is really muddy, or maybe we'll say, muffled. When each pickup is isolated, they are bright and alive, but the blend sounds like their underwater. With the previous preamp, this wasn't an issue. It didn't have the presence that the Bart does, but the blend was as clear as any other setting.

Did I buy a busted preamp? Or are there other factors at play possibly with this strange combo of wires?
I know little about electronics, so I beg a dumbed down answer or advice.

Thanks

 

[line6man]

Are the pickups out of phase? Try reversing the leads on one of them.

 

[Luke Warm Water]

Are the pickups out of phase? Try reversing the leads on one of them.

Hmm...I'll check. My tech did it. I haven't looked. Would that cause the blend to muddy?

 

[LoveThatBass]

Hmm...I'll check. My tech did it. I haven't looked. Would that cause the blend to muddy?

Looking may not tell you anything. It can be connected in the manor you would normally connect it and be in phase with another pickup of the same brand/type but out of phase with the pickup on your bass. What you must do is reverse the new pickup's wire leads and see if it works normally now.

 

[line6man]

Hmm...I'll check. My tech did it. I haven't looked. Would that cause the blend to muddy?

No, it causes a thin and nasal tone, but it's the first issue that comes to mind when there is an issue when pickups are blended, but not when they are soloed.

 

[Hopkins]

Definitely not the preamp, if it works fine with isolated pickups. I am pretty sure @line6man hit the nail on the head with the out of phase issue. Your tech should have never let it leave the shop with that issue.

 

[maurilio]

What value is the blend pot?

 

[Luke Warm Water]

I don't have much time to respond at the moment, but I really appreciate the conversation and the thoughts.
I'm much more optimistic now. I would say this though - I'm questioning whether or not I have it backwards.
The blend setting does sound unusually muddy, but not obscene. It sounds 'almost' normal for a bart...almost. However the solo settings are unusually bright. Neither setting sounds 'broken' per say; both settings just sound a little off. It was the stark contrast between them that caught my attention, going from loud and bright to underwater.