New Wiring Day! PCB to CTS

Discussion in 'Tonefreaks' started by Axis39, Oct 12, 2017.

  1. Axis39

    Axis39 Senior Member

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    Wasn't happy about the pot tension on my recently acquired '15 Less Paul Plus P-90. They are rather stiff. They sounded fine and the taper wasn't bad. But, I really like the CTS Vintage Tape pots... So, a pair of Russian PIO caps and Bob's Yer Uncle.

    Since I had a tough time finding info, I figured I'd pop up a few notes on the swap. Hopefully the next idiot looking to swap out their PCB in a P-90 based guit will find some help.

    There were two difficult pieces to the puzzle:

    1) working with 24 ga wire that was all right at the limit or too short
    2) color codes are not the same for both pickups:
    - 5 wires on both pickups
    - neck uses Red as hot, Black as neg and bare for shield
    - bridge uses White as hot, Green as neg and should as ground
    - other two wires are unused

    I had to chase down the pickup wires by finding the resistance of each pickup (and of course, I forgot to note them).

    Because I left the heat shrink labels on each pickup wire, I had to add a little wire to each pickup negative to reach the pot backs. I also didn't replace the output wires, so had to extend the negative there too. The green wire from the switch did not reach the signal wire from the output jack. I ended up slicing off the nice labeled heat shrink from the output jack and added wire to both the signal wire and the braided shield ground wire.

    I thought about removing the labels from the pickup wires and shortening those runs up a touch for neatness, but in the end left them on there.... I'm not overly happy about the extra wire from the pickups, but since I doubt I'll pull the covers off again any time soon, and it's quiet as can be, I'll just leave it alone.

    Overall it was a relatively easy job (But, i've done a ton of guitar work and a little amp work). I think total the job took less than an hour.

    The verdict on the swap is a funny one, actually. I mean, I love the way it feels now and I love the tone. But, I was actually a little surprised by the results, especially after measuring the old pots. The new CTS were all under 500k - 472, 474, 474 and 487. The Gibson pots were 489, and three above 500. I would think that would have made it slightly (and I really mean slightly) darker with the new pots. But, it's actually the opposite, it's a touch brighter, even a touch punchier. Not, night and day, but noticeable to me. The tone sweep is definitely different, and more useable.


    Overall a mod I'm glad I spent time and money on.
     
    Last edited: Oct 13, 2017
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  2. Axis39

    Axis39 Senior Member

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    So, I did my Double Cut Special yesterday (and broke a knob trying to get it off... errr).

    The thing that really struck me was the difference in PCB thickness between these two guitars. The Less Plus has a pretty thick PCB and traces. The DC Special was paper thin!

    I was also really surprised by the size of the Orange Drop in this guitar... in the Less+ it was a tiny, tiny little cap!
    [​IMG]

    I really don't care for the four conductor pickup wires. What a pain to fiddle with! I probably should have cut the black insulation back further to make a neater job. But, I'm okay with it as it is. I was happy that I replaced the out put jack's wires... They were a touch short.

    I tried a Mallory 150 series .022 cap in this guitar and I did 50's wiring on it too. Played it out Wednesday night and liked it. I really love these lower tension pots! I like the 'vintage' taper too.

    Same set up on wires: neck using red/black and bridge using white/green. At least it was consistent.
     
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  3. C.J.

    C.J. Senior Member

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    At least you can still find a use for the PCB...

    [​IMG]
     
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  4. C_Becker

    C_Becker Dat Gibson smell Premium Member

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    ^^LOL
    As for cap size, if you have two caps of the same capacitance, the larger one will be rated for higher voltages. Since the voltages in our guitars are very smaller, it doesn't matter.
     
  5. Axis39

    Axis39 Senior Member

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    I have a feeling this would be humorous if I could see the picture... Wonder what security settings I have going that I don't see everyone's pictures.

    Yeah, I'm hoping I never see 400 volts through my guitar!
     

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