Rickresource Rickenbacker Forum

My 1999 (2010 RI) has an odd quirk. One of my favorite "thumpy" settings is full volume on the neck pickup and 1/2 to 3/4 volume on the bridge pickup. If I lower the neck pickup volume knob slightly the overall volume rises and it appears to be the neck pick up getting louder and the bridge pickup getting quieter. When the pickups are soloed everything seems fine.

Chris at Pick of the Ricks tried replacing the neck volume pot to no avail. So to avoid ripping parts out randomly I thought I would ask here first for help. Point to point measurements perhaps? Help!

Here is how my 4003 (09/10 mfg) handles: Both pups start on full. When I lower the volume on the neck pup 1/8 ~1/4 turn or so, the overall volume increases. That is normal.

Sounds like you are just getting rid of any comb filtering between the two pickups, which boosts the overall volume and usually makes things sound more bass-heavy and less mid-heavy. Do you know if there is a cap in-line on that bass? If so then it probably isn't comb filtering because the cap will keep the pickups from "talking to each other" in that way.

cassius987 wrote:Sounds like you are just getting rid of any comb filtering between the two pickups, which boosts the overall volume and usually makes things sound more bass-heavy and less mid-heavy. Do you know if there is a cap in-line on that bass? If so then it probably isn't comb filtering because the cap will keep the pickups from "talking to each other" in that way.

I believe it does have the cap installed (the bass is with Chris, I will check to be certain). If indeed it does, possibly a bad cap then?

My favorite setting on my '08 4003FL is cap in, full treble with the neck rolled off about 10-20% - you can really hear a tone change if you played a sustained note and roll off the neck PU. As an experiment, I just tried it with and without the push/pull pot.

Push/pull knob in (4003 mode):

1. Full bridge and neck - highly bass with moderate treble;
2. Full bridge and neck rolled off 10-20%: I hear a reduction in bass, but still a full tone (but not louder). I actually sense more mid in this configuration.

Push/pull knob out (4001 mode):

1. Full bridge and neck - slightly less highly bass with a much more distinct, crisp treble sound;
2. Full bridge and neck rolled off 10-20%: I hear a substantial reduction in bass and volume, and a somewhat weak tone. Not a great setting for me.

I'm not sure how your V63 compares to this in terms of wiring, but I thought I'd share.

tmossman wrote:My 1999 (2010 RI) has an odd quirk. One of my favorite "thumpy" settings is full volume on the neck pickup and 1/2 to 3/4 volume on the bridge pickup. If I lower the neck pickup volume knob slightly the overall volume rises and it appears to be the neck pick up getting louder and the bridge pickup getting quieter. When the pickups are soloed everything seems fine.

Passive pickups aren't simple voltage sources that you can mix like two separate channels on the PA. They are complex combinations of resistance, inductance, and capacitance. When they're connected together, they affect each other more than you might expect.

With the "backwards" way the volume pots are wired (so that turning one pickup down all the way doesn't completely kill output from the other), turning a volume pot down slightly adds resistance between the two pickups, altering the way they interact with each other. I've found there are a lot of interesting tonal variations to be found be backing off one volume control or the other, and obviously others on this forum have noticed this too

So there's likely nothing wrong with your bass - you've just discovered some new tone space to explore!

Thanks guys.

My volume increase is greater than any 4001's or 4003's I have ever owned (or played for that matter). it is also a very abrupt change of volume and tone (exponential vs. linear). My guess is that one or more component is (slightly?) out of spec. I could sit down and model the circuit in a SPICE package, but I was hoping for one electronics gurus would chime with a quick "oh your xxx is probably bad/wrong" comment.

Do you get a similar disproportionality doing the reverse? Backing off the opposite volume control I mean.

This could also be because, while there is normal comb filtering here, we are talking about a 7k pickup and a 14-15k pickup, with different impedances as well. The way they affect each other will be offset in certain ways. You may just be witnessing how the Horseshoe and Toaster interact as far as comb filtering goes--a more heterogeneous response than two evenly matched Hi-Gains. From what you've said so far nothing sounds out of spec or bad. Sound clips may help us elucidate problems by actually hearing it... words only get so far.