Nordstrand 3B-4B preamp wiring confusion.

[archer121]

Hey guys, I received a Nordstrand 3B-4B preamp today and am a little confused about how to wire it. The preamp comes prewired and it seems that all I have to do is connect the pups and be good to go. The problem I'm having in figuring out what I need to do is that the diagram in the wiring instructions doesn't seem to match how the preamp is wired so I'm confused about what it is I have to do when I install it.

Here's a picture of the diagram provided...



and here's a picture of the blend pot on the preamp (sorry it's so blurry)...



The diagram seems to indicate that there should be a ground wire connected from the top left post to the pot's case however that wire on the actual preamp does not seem to go to a ground but instead to the bottom middle post on the volume/tone stack. Also, the diagram shows a wire leading from the bottom left post of the blend pot and seems to indicate that this wire should be connected to the preamp but there isn't any wire there at all and the preamp is completely encased (except for the trim pot) in resin so it doesn't seem I could add one even if I were supposed to.

What do you guys think? Am I just reading this all wrong and all I have to do is connect the pups as indicated and ignore the rest or what?

[maurilio]

Not that we can see much with that pic....


the diagram shows a different blend pot. With the one you have wire the bridge hot to the center bottom lug and the neck on the top one. the hot from the blend goes to the vol pot and than to the p/a switch

M

[archer121]

Thanks. There isn't a passive/active switch with this pre but according to the diagram I'm thinking I just need to connect the +/- of the pups as follows:

The "-" of both the bridge and neck pups to the lower left post, the "+" of the neck pup to the lower center post and the "+" of the bridge pup to the upper middle post. Is that all I need to do? Is the other wiring shown just extraneous and nothing I need to worry about as the pre and pots are pre-wired?

Here's a better pic of the diagram so you can see where I'm coming from.

[Carey]

You have the +'s backwards. The bridge goes to the bottom and the neck goes to the top. The - just need to go to anything that's grounded. They don't necessarily have to go to the lug on the pot. You can ground them to the sleeve on the jack, the back of an eq pot, or foil in your cavity. All this should be connected in a properly shielded and grounded system and anywhere in that scheme is fine to make the connection.

I'd recommend reading the blend pot primer on the support section of our site. It may help your basic understanding of how a blend pot works and the best way to hook it up.

[archer121]

So you're saying I've been looking at it upside down... that would explain why I'm so confused here.

Looking at the diagram again, what you said does make sense, though.

I'll check out the primer and see what it says. I'm a long way off from installing this but I want to get a firm grasp of the wiring and what I need to do when the time comes.

In case you haven't noticed, I'm a total novice at this.

[archer121]

I think I'm starting to wrap my head around this but I'm still a litle confused about the ground. I'm thinking I'll have to solder a ground wire to the post indicated in the previous diagram which I can then attach to the cavity shielding along with the bridge ground in order to ground the system. Is that correct?