650C potentiometer discovery
Posted: Thu Sep 13, 2012 9:46 pm
I bought a used '00 model JG (rocks!) 650C about five or six years ago. While I really like the looks and the way it plays I've never liked the tone very much. It has always seemed dead/dark/veiled somehow. Recently I started thinking about trying a coil split or even swapping out the HBs for HiGains. Luckily I opened it up and poked around before buying any new parts. Here's what I found in this completely factory original guitar. The volume pots measured 168k and 173k! The tone pots measured 162k and 166k! I know these are supposed to be 250k according to the published wiring diagrams and even a 20% variation can be expected in some pots, but here we're talking about 30% at best and 35% at worst and all are on the low side.
That seemed like at least part of the trouble so I ordered two 500k CTS pots along with some parts for another restoration project. I changed out the volume pots for the new 500k units and now the guitar sounds like I would expect! The tone is alive and dynamic with more midrange grunt than a HiGain. I might put some 250k or 330k tone pots in next, but that is less of an issue for me. I wonder if RIC got a bad batch of 250k pots back in 1999 or 2000? Has anyone else found this? I imagine it would be less noticeable in a single coil guitar, but anything with a HB would definitely sound darker than it should. If you have a 650 model it seems worth a check--especially if you find it too dark sounding. $20 in pots is a lot cheaper than a pickup swap!
Doug
p.s. Before anyone asks...yes I did measure the pots correctly. The posted numbers are from the outer lugs--volume pots out of the guitar, tone pots still in, tone up all the way (the DC measurement is isolated by the tone caps).
That seemed like at least part of the trouble so I ordered two 500k CTS pots along with some parts for another restoration project. I changed out the volume pots for the new 500k units and now the guitar sounds like I would expect! The tone is alive and dynamic with more midrange grunt than a HiGain. I might put some 250k or 330k tone pots in next, but that is less of an issue for me. I wonder if RIC got a bad batch of 250k pots back in 1999 or 2000? Has anyone else found this? I imagine it would be less noticeable in a single coil guitar, but anything with a HB would definitely sound darker than it should. If you have a 650 model it seems worth a check--especially if you find it too dark sounding. $20 in pots is a lot cheaper than a pickup swap!
Doug
p.s. Before anyone asks...yes I did measure the pots correctly. The posted numbers are from the outer lugs--volume pots out of the guitar, tone pots still in, tone up all the way (the DC measurement is isolated by the tone caps).