Some advice on my Ric 4001 please

IME weird tapers are from worn or goofey pots or improper/damaged wiring in a passive bass.

I have had several preamps that you could only use about 1/4 of the taper before it was either wide open or all the way closed.

In all of those situations, replacing the pots solved the problem.

You should have a DC resistance that Rick will give you for your pickups. Ohm them out and that will tell you if you have shorts in the windings (make sure all pots are wide open). A short in the windings will "reduce" the "turns" of the pickup windings because the affected areas in the coils will produce nothing when they are shorted.

That should tell you if they are functional from an electrical standpoint. You can also check the taper of the pots while you have your meter out if you choose to.

I can give a step by step if you are comfortable soldering and using an ohm meter. If not, I suggest you take your vintage instrument to a tech and have them look at the electronics instead of trying to learn on an instrument.

 

I sounds like a wiring problem.

check for broken solder connections.

If you replace the pickups then try the new 4003 high gain pickups, and remove the .0047 capacitor.

 

The Rickenbacker 4001-4003 wiring diagram is available on the Ric website if it helps

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

Oss

 

Rhoades music is a good dealer. I was there years ago when I used to live near them.

Get an ohm meter and put each pickup on the ohm meter. Older Ric pickups will read 8k ohms and newer Ric pickups will read 11k ohms. A weak or bad pickup will read something like 2k ohms.

If both pickups read 8k ohms or higher then you have 2 good pickups. The next thing to check is the stereo / mono jack ric-o-sound setup. This is a place where Rics can fail and it is cheap to fix. The replacement part is cheap. I will sometimes rewire my Rics with 2 mono outputs.

Another point of failure would be a disconnected wire in the wiring harness. check the schematic listed in the other post and follow the wires.

I have had very good results by rewiring a 70s 4001 with all 250k ohm pots and no .0047 capacitor and the normal .047 tone capacitors, and the original pickups.

Ric pickups don't usually go bad, but sometimes they do. Also check the wires that attach to the pickup itself.

A simple reslodering of a connection may be all you need.

Also I know a guy in Portugal who can rewire old Ric pickups to the original specs and also make replacement Ric pickups wound to the original specs.

 

Checking the taper of pots: To check the taper of your pots, grab your meter and soldering iron.
1. De solder the wires from the pots but leave them close by for easy reassembly.

2. Look for an A or a B written next to the value of the pot. Ex. B500K

3. Turn the pot all the way to one side. Measure the two outermost legs of the pot. They should be pretty close to the value stamped on the pot.

4. Measure from the center leg to one of the outer legs. You should get 0 ohms or the value stamped on the pot.

5. B taper: The ohms should decrease or increase in a "smooth" motion as you turn the pot from left to right or vice versa. Any large bumps or dead spots indicate the pot needs to be replaced. You should see the ohms add or subtract for the full length of the taper.

5. A taper: This will have a large "bump" in the taper as you check it. The taper should ramp up faster than a B pot towards the end. If you hit this ramp very early on, with a large "area of nothing" after it, the pot needs to be replaced. This bump should occur very near the end of the taper. Not in the middle or in the beginning. There are variations on this design, but they electrically work the same.

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Pickups: A DC resistance will tell you the condition of the coils in your pickups. Pickups are nothing more than little generators. They use many many many many turns of wire to produce this power when the string vibrates over them. If we remove some of the wire, the strings will not induce as much current in the windings and the output will not be as high. The same will happen when there is a short in your windings.

Why they short: The wire in your pickups is coated with an insulator. It is clear, but it is there. Sweat, heat, vibration, and age all break this insulator down until a hole wears and two parts of the wire short together. A short may be bypassing 10 turns of wire or it may bypass several hundred turns. The effect is the same- less or no output from the pickups.

How to test: (Non center taped coils) There will be two wires coming out of each pickup. Desolder them both from the pot and ground. Measure the resistance between the two wires and compare with what Ric says it should be. Higher: corrosion or over winding has increased the resistance. Corrosion will make it harder for the voltage your meter sends through the pickup to come back out. Think of using a cheap extension cord for a heater- gets warm. Can't do it because of too much resistance. Too low and you are "missing" some windings and hence have less potential in your coils.

The center taped coils or anything else like that will require that you find the resistance between the taps and "ground". This can get confusing fast without a wire diagram.

Good luck with your diagnostics.

* The resistance will simply check for shorts or opens. Will do nothing for telling you if they have good tone, mojo, or anything else. Too many other conditions factor into the tone.