non independent volumes on a 79 4001

[crox]

Dear fellow members, I hope someone could help me on this topic. After a lot of searching, I recently acquired a '79 autumnglo 4001 in great conditions. Tone is great too, but there is a problem. With rick-o-sound only jack connected, volumes are not independent. At maximum volumes, the switch works and neck/bridge pickup are properly engaged one at a time... but if I lower one pickup volume, the other also disappears, and vice-versa. It seems also that both tone controls doesn't change the tone in audible (by me) way... Maybe something wrong in the wiring? Thanks a lot in advance and greetings from Italy.

[jdogric12]

Yeah that sounds funky. Try Joey's Bass Notes for wiring info: http://www.joeysbassnotes.com/

Welcome!

[johnallg]

Welcome aboard! Definitely does not sound correct. Here is the RIC wiring diagram, but your 4001 pot values should be 250k for volume controls and 500k for tone controls. Also, the C3 .0047uF cap will be there. I'd verify it is wired like this and pay special attention to the mono jack - it is the switching to put both pickups together for the mono output or unconnecting them for the Ric-O-Sound stereo out. Also be aware putting a mono (standard) cable into the Ric-O-Sound jack will give only the treble bridge pickup, not the neck pickup.

http://www.rickenbacker.com/pdfs/19507.pdf

[jingle_jangle]

It sounds like somebody might have tried to re-wire it like a Les Paul...I've run across this once or twice. The wiring diagram should solve this one.

[Seans]

If its not the fact it's been incorrectly wired, it may be a wire touching where it shouldn't, I've had this on a replaced cap that was grounding on another part of the switch.
Or, the normal Jack socket has moved round and is in switch mode constantly, take a look and see if the contacts are touching without a jack plugged in, if so you need to spin it to a position that gives it space to be open.

[crox]

Thanks for the replies. In fact, I mis-reported the problem, I apologize for that. After a deeper examination it seems that the output is bi-mono (same output on both channels) with the impossibility to mix the volumes, for they have to be both at max or near the max level (If I try to lower one, the other also disappears). I can only exclude one of the pickups with the switch, but in this case the sound of the selected pickup goes to both channels. Maybe is a mono wiring expecially requested by the customer? Thanks again,

[marcinkus]

Maybe is a mono wiring expecially requested by the customer?

This is impossible... post a pic of the wiring please.

[jdogric12]

Dual mono wiring is stock on 360/12v64 guitars, but it's very unlikely to be on a bass... perhaps someone did that because (fill in the blank).

[JakeK]

Dual mono wiring is stock on 360/12v64 guitars

...and 360/12 Carl Wilson guitars, too

[crox]

Thanks to all. I am going to post a picture of the actual wiring so maybe anyone more expert than me could give me an advice.

[johnallg]

Thanks to all. I am going to post a picture of the actual wiring so maybe anyone more expert than me could give me an advice.

Great, make it a hi-res closeup.

[crox]

Hi, sorry about the delay. Here is the actual wiring


Any help would be appreciated.

Thanks!

[johnallg]

Looks like the switch is hosed up where the soldering is. Looks like the pickup wire and the cap are on the one lug of the switch and the two lugs are soldered together. Both switch sides need the 4 lugs separate, the wires from the pickups on the one set, and the tone .047uF caps to the other set of lugs.

Here is a correctly wired set. Ignore the red wire bypassing the tiny .0047uF cap. That gives the bridge pickup full range rather than the thinner sound with the cap still in the circuit.

[crox]

Hi, problem solved. A naked wire, the one with the small capacitator, was touching another wire near the pot (center fo the picture). The capacitator itself was soldered to one of the pot. After having shielded the wire and detouched the capacitator all magically turned as it has to be. The tone controls keep to have a small effect, but so are the ones on a more recent (and correctly wired) 4003 that I owe. Thanks to all and johnallg, it's great to share with competent guys like you. Regards,

[johnallg]

Hi, problem solved. A naked wire, the one with the small capacitator, was touching another wire near the pot (center fo the picture). The capacitator itself was soldered to one of the pot. After having shielded the wire and detouched the capacitator all magically turned as it has to be. The tone controls keep to have a small effect, but so are the ones on a more recent (and correctly wired) 4003 that I owe. Thanks to all and johnallg, it's great to share with competent guys like you. Regards,

Glad you got it. A picture is usually worth a 1000 words, and in this case helped a lot. Congratulations and enjoy!