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Just a small Problem in the Bass circuit?
Posted: Wed Dec 13, 2006 2:47 am
by heinpete
...when I swapped the electronics of my 4003 and 4001 I thought everything was connected in the right way. However I realized that either tone pot influences both PUs when the PU-switch is in the middle position (same issue with both basses). I never realized that, as I hardly use the tone pots anyway (I rather use the vol pots to also decrease the treble a bit). Did I misconnect any wire? Need some help from the forumite brothers and sisters!
Posted: Wed Dec 13, 2006 4:06 am
by ken_j
Sounds correct to me per your description.
Posted: Wed Dec 13, 2006 4:21 am
by john_l
That can't be right. I had a similar problem with my 4003S. Check all the wiring against a schematic, and pay special attention to grounding.
Posted: Wed Dec 13, 2006 5:06 am
by heinpete
You see guys, that were just the same ideas I was going through: 1) Checking the schematics (found no difference, ground is anyway everywhere)
2) Thought that might be correct, as I could not have observed it before (I never did use the tone pots).
PLEASE SOMEBODY CHECK WITH HIS/HER STOCK-BASS!
Did somebody ever come across that problem?
Posted: Wed Dec 13, 2006 12:32 pm
by rictified
Does your bass sound exactly the same with either tone turned off with the switch in the middle or do you get more treble roll off with both tones off as compared to only one off? If you get less treble with both tones off it is functioning normally. Either tone control will affect the sound with the switch in the middle especially if both pickups are putting out approximately the same amount of sound.
Posted: Thu Dec 14, 2006 2:49 am
by heinpete
Bob: Thanx for your advice, I checked immediately, but it is a clear "symptom": If one tone is turned off the other tone pot has no further influence on the overall sound and vice versa! I do not get more treble roll of with the second tone pot. There should be a reason? HELP!
Posted: Thu Dec 14, 2006 3:32 am
by john_l
Check each pickup individually, switch up and switch down, and see if both tones work on shen a single pickup is used. On my 4003 the pickups couldnt be selected individually because of a wiring fault at the selecter switch. And also make sure you are not using a standard 1/4 guitar cord in the Ric-O-Sound jack.
Posted: Thu Dec 14, 2006 4:15 am
by rickcrazy
Just my 2 cents: on any 4001 bass having the "old-style" wiring, i.e. with treble-pass capacitor and approx. 8.0 K pickups, when both volume controls are set full - and only then - the bass tone control does affect the treble pickup tone, and conversely, though to a lesser extent. Output from the treble pickup also is slightly impaired at said setting.
Posted: Thu Dec 14, 2006 6:16 pm
by edski
I haven't been playing my 4001 much, and the last few years I played it I was almost never having both volumes open all the way...
I have a Jazz Bass that was being abused by a room mate. It displayed the same "bleed over" behavior. Strangley, it seemed to go away, but I've since replaced the PU's. But it is still the same pots...weird.
I would start to re think what I did, and try to undo the work. That's one reason I'm so loathe to mod my Laredo - sure dual concentrics would be great, but for me the bass is playing and sounding great. Why mess with it??
All I can say is trace the wiring as it exists, and follow the schematic at the same time. Fundementally the circuit is not that exotic. It's a couple volume pots and RC filters in parallel. With a switch...maybe theres a crossed wire in the switch?
Can you post a picture? That might give a few suggestions.

Posted: Thu Dec 14, 2006 8:23 pm
by rictified
When you unhooked them where did you unhook the wires, at the pickup wires? You must have left it mostly intact right? I wouldn't bother looking at factory intact wire, start where you had to soldier it back together. I would guess bad grounds somewhere too. Do you know anyone who has one close to you?
Posted: Fri Dec 15, 2006 6:29 am
by jwr2
When I rewire a Ric bass I like to have one around that is wired up right as a template ... and it is good to learn how to read schematic drawings ... or maybe take some photos before you rewire ...
Posted: Fri Dec 15, 2006 12:27 pm
by heinpete
Thanks again Bob and Jeff. In my procedure of swapping the electronics from the 4001 and the 4003 I always "un"soldered one and the resoldered
it at the other bass as soon as possible. But Jeff is right, I forgot to take a picture before. The circuit was controlled with the schematics (as far as I can read them) from the Ric homepage. Everything seemed to be correct! However there MUST be some mistake! If anybody has a nice pic of an original circuit in the cavity, that might help. Strangely both basses now exhibit the same issue!?
Posted: Fri Dec 15, 2006 8:56 pm
by rickenbrother
Peter, there are wiring diagrams on my website found in my profile, that you can check your wiring with.
Posted: Mon Dec 18, 2006 10:33 am
by heinpete
ThanX Joey and Jeff!!! Your advice and pics are of great help. Over Christmas holidays I will take my time to check each individual wire. The circuit so far (first glance) seems all right. Maybe some "internal" problem with one single wire. Still a very strange thing. I will post the results a.s.a.p.
Merry Christmas to the Forum from the small German section.
Pete
Posted: Wed Jan 24, 2007 10:54 pm
by heinpete
So, now back to the wiring problem of last year:
I finally had some time to check my 4003 with a pic Jeff provided. The tone pots were clear in wiring at this pic, the vol pots not so much. However I tried to make my way through, together with the original diagram from Ric Co. I still do not find any mistake. So I went to a shop where I knew it had Ricks at some year ago and was lucky there was a late ‘73 4001. To my surprise this bass had exact the same issue like mine: The tone pot of either PU influences the total tone when applied in the middle position of the PU selector!!!
Slowly but surely I come to the conclusion, that this might not be a mistake, but rather a “feature” of the 400X wiring.
Dear Forumites, can you please check with your basses and give some reply?
Nevertheless this wiring seems fairly practicable as in the middle position you only need to use either one of the tone pots and if you select to play only one PU, then the individual tone pot of that PU also works fine.