TECH Help!!!Problem with Vintage p90

[straightblues]

I wired in some vintage P90's (these are old ones I have had laying around) in to my Les Paul copy. It had 250k pots in the guitar so I left them in and did the 50's style wiring. The output was low and very bass heavy. So I decided to use the wiring suggested by the Seymour Duncan site and 500K pots all around and .022 caps. I have now done this and again, the output compared to my other guitar with Duncan 59's in it is at least 20% lower and it is again are very bass heavy. I have also compared them in tone and output to my Lollar P90's and again, they are significantly lower and output and are way bass heavy. I have used an ohm meter and the neck measures 8 and the bridge 9 (just slightly hotter than the Lollars). This is very near the Duncan specs for these pickups. I have adjusted the height of both the pickups and the pole pieces. Any other suggestions to fix this problem?

 

[John Wymore]

Re: TECH Help!!!Problem with Vintage p90

Check your 50's wiring for the caps. It sounds like you might be dropping the highs off through the caps all the time. Do the tone controls do anything now?

 

[straightblues]

Re: TECH Help!!!Problem with Vintage p90

Check your 50's wiring for the caps. It sounds like you might be dropping the highs off through the caps all the time. Do the tone controls do anything now?

I abandoned the 50's wiring and am now using the Seymour Duncan P90 schematic. Yes the tone pots are working but don't seem to be nearly as effective as normal.

 

[straightblues]

Re: TECH Help!!!Problem with Vintage p90

Anyone have any other suggestions!!!!!!!

I used soild copper 4 conductor wire made by Belden to wire the switch to the guitar. I don't think this would cause a problem but it is the first time I have used it. What are you guys using for the 4 wires that need to go from the switch to the guitar?

 

[Artie]

Re: TECH Help!!!Problem with Vintage p90

The first thing I would check is the cap value. What you're describing is exactly what would happen if you accidently got a 22uf, or .22uf, instead of a .022uf.

Sometimes cap values can be hard to read and interpret.

 

[straightblues]

Re: TECH Help!!!Problem with Vintage p90

The first thing I would check is the cap value. What you're describing is exactly what would happen if you accidently got a 22uf, or .22uf, instead of a .022uf.

Sometimes cap values can be hard to read and interpret.

I have tried three different sets of caps and it doesn't seem to change much.

If I wired from the pickup directly to the output jack, would I be able to hear if I had a pickup problem? Is the tone wired directly the same at volume and tone knobs on 10? I am afraid these pickup are just bad. They are old and I bought them used.

 

[Artie]

Re: TECH Help!!!Problem with Vintage p90

You can definitely wire the p'up direct to the output jack for testing purposes, just keep in mind, a volume control on "10" still adds some "character" to the sound of the p'up that will be missing, and a tone control on "10" still bleeds off some highs.

So, if wired direct, the pickup will tend to sound bright and shrill.
BTW - some folks like their p'ups wired this way.

 

[straightblues]

Re: TECH Help!!!Problem with Vintage p90

You can definitely wire the p'up direct to the output jack for testing purposes, just keep in mind, a volume control on "10" still adds some "character" to the sound of the p'up that will be missing, and a tone control on "10" still bleeds off some highs.

So, if wired direct, the pickup will tend to sound bright and shrill.
BTW - some folks like their p'ups wired this way.

I wired each of them direct. Yes both the pickups are working fine. Like you said they are a little shrill that way but I got full volume and the bass heavey sound was gone.

That must mean I have a wiring problem. I have used 50's wiring with 250 and 500 k pots. I have also used the wiring schematic from Seymour Duncan. I have completely rewired at least 5 times. I have used two different sets of .022 caps and one pair of .047 caps. The only thing consitant during this whole experiment was this 4 conductor wire from the new switchcraft togle switch to the guitar. Again, I am using a 4 conductor wire, I believe the wires are 20 guage solid copper made by Belden. Could this maybe be the source of my problem? It is the only thing I haven't changed. What wire are you guys using for the four leads comming from the switch to the guitar cavity?

 

[Artie]

Re: TECH Help!!!Problem with Vintage p90

Is there any chance that you could post a link to the schematic that you're using?
I know there are some oddities in LP wiring, and I'm assuming you're using 2 vol, 2 tone, and the oddball switch that has a ground lug on it.

 

[straightblues]

Re: TECH Help!!!Problem with Vintage p90

Is there any chance that you could post a link to the schematic that you're using?
I know there are some oddities in LP wiring, and I'm assuming you're using 2 vol, 2 tone, and the oddball switch that has a ground lug on it.

I currently have it wired exactly like the schematic from Seymour Duncan for their P90 pickups. I am using a switchcraft straight toggle 3 way switch; switchcraft jack; 4 Allparts CTS 500 K pots; and 2 .022 mylar caps.