changing pickups in USA S-500 issue...

Fri Aug 24, 2018 7:00 am

I do love the MFD pickups for what it's worth, but in hopes to get more use out of my S-500 I wanted to change to some mini HBs that suited the band I play in more. I bought the SD Everything Axe set (uses a little 59 in the bridge which I have in my ASAT and it sounds glorious)..
I dropped them in, and they sound shrill and lack any body whatsoever. :crazy: My assumption is that it may have to do with the potentiometer values? (i have a super elementary knowledge of electronics which is why i'm asking here). Would I need to change the stock volume pot value to get these HBs to sound as they should, or perhaps is it something else altogether?

Thank you all!

Re: changing pickups in USA S-500 issue...

Fri Aug 24, 2018 7:32 am

Yes you will have to change the pots and caps. I don't know what values to use, but you should be able to find it on the SD website. Remember the circuit topology on the S-500 is completely different with the PTB circuit and expander switch. You will have to switch to a circuit that fits the SD pickup set. Since you have to change things anyway, I would leave the MFD pickups wired in the current pickguard, then buy a different pickguard and wire it with the SD pickups and circuit. They you can more easily swap around.

Re: changing pickups in USA S-500 issue...

Fri Aug 24, 2018 8:14 am

thanks for confirming my suspicion. Just made an appointment with my tech to rewire the whole shebang.

Re: changing pickups in USA S-500 issue...

Fri Aug 24, 2018 6:34 pm

fromthebark wrote:thanks for confirming my suspicion. Just made an appointment with my tech to rewire the whole shebang.


What did you do with the S-500 pickups? Looking to sell them?

Re: changing pickups in USA S-500 issue...

Fri Aug 24, 2018 7:33 pm

If you look up the Duncan Everything Axe diagram, 250k pots are used. Makes sense, they sell them as replacement Strat pickups. 500k seems to work well for people too; from my experience jumping between 250k/500k is not really enough to screw things up one way or the other with most pickups anyway.

Did you keep the PTB system when you installed them, or do you intend to? Or did you wire it as a Strat VTT with those same pots? The PTB pot values are 250k, 500k, and 1 meg; to be frank I'm a bit surprised that's enough to make the guitar sound shrill beyond use, but it would still not be quite the same as in your Tele. Then again I also don't know how the Everything Axe set would interact with the PTB - But off-hand I wonder if you installed them out of phase or parallel by accident? Know a tech is looking at the guitar at this point but I'd check everything DC-wise with a multimeter at the jack.

Re: changing pickups in USA S-500 issue...

Fri Aug 24, 2018 8:19 pm

dhgleaves,

If you wire the new pups up in the same way to the pickup selector switch as the old ones and made no other changes, you indeed have created a bit of a weird beast. The PTB on your S-500 uses a 250kΩ AT volume pot with 200pF treble bleed cap, 500kΩ AT pot in series with a 22,000pF (.022F) cap to ground, and a 1MΩ Reverse AT pot with 2,200pF (.0022µF) treble bleed cap. The latter pot may also have a 1,000pF (.001µF) cap soldered from the signal end to ground; some PTB circuits have them, some don't. As Danley suggests, you might want to go to 250kΩ AT or 500kΩ AT across the board with the tone pot for the neck pickup in series with a 50,000pF (.050µF), no other caps, for a more familiar Strat tone stack.

Hope this helps,

- Jos

P.S. Restore the old configuration and put the new pups, pickup selector switch, pots, and caps on a separate pickguard that is fairly easy to swap out.