Problem: Volume drop in middle position

[hunter]

Hi all,

I have something weird happening and can't get my head around it.

I put back in the stock McCarty Bass Humbucker in the neck position of my PRS, paired with the VHII bridge.

Both pickups sound great on their own, but the middle position is overly thin and drops in volume.

I took the following measurements:
-8.9K resistance on the VHII Bridge
-8.1K resistance on the McCarty Neck
-4.3K resistance in middle position

Is it possible that the two pickups are out of phase to each other?

Is this the problem? How can I fix it?

The VHII is 4 conductor, the PRS is 2 conducter with an extra white cable that switches the PU to Single when connected to ground.

Thanks in advance guys!

[AndyR]

It does sound like phase, hunter...

How you switch the phase of one humbucker without making its cover hot is beyond me though :lol: - I'm fairly certain you can do it with the 4-wire VHII, but I'm guessing someone else will have the full details for you...

[hunter]

Oh I just read in another post that PRSes have reversed magnets on their neck PUs ... strange only that I didn't have this issue in combination of PRS neck with the PRS bridge PU ... ?

[Philly Q]

PRS have reversed magnets on the neck pickups when they use the 5-way rotary switch, like on the old Custom 24s.  It's so the "split" positions work properly (I don't know if that's a phase issue, or whether it's to get hum-cancelling in the split positions).

I'm not sure if they do the same thing on MCartys, because you just have a normal 3-way switch plus the push-pull coil split.

Anyway, it does sound like they're out of phase.  You just need to swap the wiring on the VHII round (so red is ground and black is hot).

[hunter]

PRS have reversed magnets on the neck pickups when they use the 5-way rotary switch, like on the old Custom 24s.  It's so the "split" positions work properly (I don't know if that's a phase issue, or whether it's to get hum-cancelling in the split positions).

I'm not sure if they do the same thing on MCartys, because you just have a normal 3-way switch plus the push-pull coil split.

Anyway, it does sound like they're out of phase.  You just need to swap the wiring on the VHII round (so red is ground and black is hot).

Thanks Phil, I had tried it and strangely had the same issue with level drop, but not the thinness anymore.

Well conclusion is that I put back both stock pickups, and although they show low resistance in the middle position, they sound full. I did have a lot of fun playing ... there is something about these McCarty pickups, they sound very big and crunchy, yet airy. But I have bad squealing issues with volume/high gain.

I'll leave them in for now and try with the band, if the squealing is a killer, otherwise I might just keep them in there. In the end they were designed for the guitar, and they do make the McCarty more Les Paul like in fact.

[Twinfan]

Very odd problem you've had.  It sounds like some sort of frequency cancellation, the pickups must be quite different.

Level drop in the middle position is quite normal though I think?

[Tim]

If you have 4 con on one of the pickups, swap hot and cold, ie on the VHII make black hot and red and bare go to ground - if it is a phase issue due to a PRS mag flip this will sort it out.

[hunter]

If you have 4 con on one of the pickups, swap hot and cold, ie on the VHII make black hot and red and bare go to ground - if it is a phase issue due to a PRS mag flip this will sort it out.

Thanks Tim, I think this will work. Stupid me thought before I had reversed when I put bare and black together to tip and red to sleeve  :lol:

Doesn't make me look very smart now, after having installed like 30 pickups in my life  :?

Will try once I get sick of the McCarty squeal and the VHII goes back in!