RC - Wiring Tone Cap in Parallel?

[IceBlueBoogaloo]

So, a ways back I made some basic mods to my stock vintage JM wiring, namely installing a Free-Way switch and then wiring the RC to it to use any pickup. I'm planning on putting treble bleeds in after mulling it over, but I know that the tone cap wiring in the RC is not the same as the lead circuit; it's wired in series with the volume pot instead of parallel. It's my understanding that this rolls off even more treble than when wired parallel. My goal is to keep the same 50k cap, but have more control over rolling off volume without darkening the sound as much at the same time.

[timtam]

Indeed the rhythm circuit is wired differently to typical tone circuits. The volume pot coming off the tone wiper means there is an interaction ...


Seymour Duncan's early JM wiring diagram (below) showed a different, more typical parallel wiring (although without mentioning that, IIUC; so I'm not sure that it's 100% certain that whoever drew that diagram realized that it was different to Fender's wiring). And SD have since reverted to publishing the vintage-style wiring, as used by Fender all along.

[taherbert]

So I experienced a similar thing and went through a similar process when I build my first JM a few years ago. I was using this thread below as a basis and posted my solve in the thread.

Thread here

To summarize, I basically changed the rhythm circuit to the more traditional Fender tone circuit config so the tone wouldn't change when I rolled the RC volume down, and I also soldered a 50k resistor between the the rhythm circuit tone pot and ground so the pot range is now 100k to 50k rather than 50k-0. This brightened up the baseline RC circuit tone considerably, and although it doesn't get really dark, I would never play with a tone that dark anyway. Now when I switch to the RC with tone and volume all the way up, I take a little top end off and get a kick in the low mids that I don't get when rolling the tone down in the lead circuit, and if it's still too bright, I roll the RC tone down to get a pretty good but still articulate jazz tone without losing too much volume. If you want it to go darker, you could try different resistor values, lower being darker.

I've done this with two JMs at this point, I will say that the difference between Lead and RC circuits is much more noticeable on my JM with 1Meg Lead pots and Curtis Novak JM-V and JM-Fat pickups than my guitar with 500K pots and Lollar JM and Firebird pickups.

[IceBlueBoogaloo]

Meant to reply back to this sooner as I was driving back home yesterday. Appreciate the info from both of you. I suspected this was the cases as I looked at the guts in my Vintera and saw it lined up with the vintage wiring diagram.

So I experienced a similar thing and went through a similar process when I build my first JM a few years ago. I was using this thread below as a basis and posted my solve in the thread.

Thread here

To summarize, I basically changed the rhythm circuit to the more traditional Fender tone circuit config so the tone wouldn't change when I rolled the RC volume down, and I also soldered a 50k resistor between the the rhythm circuit tone pot and ground so the pot range is now 100k to 50k rather than 50k-0. This brightened up the baseline RC circuit tone considerably, and although it doesn't get really dark, I would never play with a tone that dark anyway. Now when I switch to the RC with tone and volume all the way up, I take a little top end off and get a kick in the low mids that I don't get when rolling the tone down in the lead circuit, and if it's still too bright, I roll the RC tone down to get a pretty good but still articulate jazz tone without losing too much volume. If you want it to go darker, you could try different resistor values, lower being darker.

I've done this with two JMs at this point, I will say that the difference between Lead and RC circuits is much more noticeable on my JM with 1Meg Lead pots and Curtis Novak JM-V and JM-Fat pickups than my guitar with 500K pots and Lollar JM and Firebird pickups.

This (and the thread you linked) is super helpful. I genuinely love the idea of the RC and I'm not interested in cutting off the trebly LC when that can mostly be handled by the tone pot. So I'm definitely interested in "standardizing" the volume-tone interaction on the RC and bumping up the whole range of the tone control to get a discrete but still useful set of sounds. My desire is to basically have your typical volume knob interactions with overdrive on the LC but be able to effortlessly switch to the RC if I want to jump in and out of clean rhythm, clean lead, and dirty lead tones.

[taherbert]

Yeah, that's basically what I use mine for. I keep my volume on the lead circuit on like 7ish, tone 5-7ish, set my amps and overdrives to be just on the clean side of edge of breakup. It's a nice sparkly but not too bright clean tone for arpeggios, clean chords, etc. Then when I want to put some stank on, I flip to my RC with volume and tone on 10 and a germanium Rangemaster treble booster. The subtle rolloff of the highs and push in the mids from the modified RC keep the treble booster from getting to harsh and the high output from the pickups pushes it into solid overdrive. It sings!