Directions for a continous 4001 cap control.

rictified · Post by **rictified** » Sat Apr 24, 2004 11:17 am

This allows you to leave your cap in your 4001 (or put one in a newer 4003 if you like) and control the amount of bass and mid that comes from the treble pickup, a presence control if you will. It is fully reversable and uses no new parts.
1. Take off the pickguard, you can do this without detuning if you are careful.
2. position it upside down with the circuit showing so the tone controls are at the top with bass tone on the left. This is actually the only way you can position it unless you want to unsoldier it and take it right out, which I wouldn't do unless it were a mint bass.
3. Unsolder the ground wire that goes to the middle lug of the treble tone control and back of the pot that comes from the bass tone control and pull it right out (unsolder it from the back of the pot first). Resoldier it to the back of the bass volume control so the bass tone is still grounded, there should be just enough wire.
4. Unsolder the the .047 uf cap that goes to the treble control and resolder it to the same place the .047 uf cap goes to on the bass control. The bass tone control now is your (treble) tone for both pickups, they sound exactly the same as before, only thing is that they are always equal now (which I always did anyway)
5. Leave your .0047 cap in the way it was from the factory (if you want to try this on a late model 4003 replace the solid wire that goes from the middle lug of the treble volume to the three way switch with a .0047 uf cap. Your treble tone control now should only have a ground wire attached to the back of the pot coming from the treble volume control. There should be nothing attached to the three lugs.
6. Solder a wire to the same lug on the treble volume control that the cap is attached to (middle lug).
Solder the other end of that same wire to the middle lug of the treble tone control.
Now solder another wire to the other end of the cap (where it is soldered to the three way switch is best)and solder the other end of that wire to the lug that is to the right of the middle lug of the treble tone control. The left hand lug should have nothing attached to it.

You are finished, tuck the wires in and use shielded wire like the stuff that is on the pickups so that the wires do not pick up noise, and you need only ground one end of the shielded wire preferably to the back of the pot.
I would make these wires as short as possible but
leave enough room to work with.
Put it back together and plug it in.

Your bass tone control now will control the amount of treble from both pickups and your treble tone will control the amount of bass and middle that is allowed into the circuit from the treble pickup.

This is how it works:
The pot works like a continously variable switch, that is how I got the idea, I already had a switch in this bass which I was not happy with as it was either all or nothing, and as I was gazing at it, I though why won't a pot work like a variable switch? It does.
When the pot is fully clockwise no current goes through it, it is forced to go through the cap which cuts all the bass and a lot of mid from the circuit. The more you turn it counterclockwise the more current is going to flow through the pot as electricity takes the path of least resistance always and more bass and treble will go into the circuit.

Try it it works! I was amazed, you can get all kinds of nice tones from it too. you can leave the treble volume on full and back off the bass volume and then dial in more fullness with the cap control as you lower the volume.

If anyone has any problems or questions just e-mail me, it is in my profile.
The best part of this in addition to it being variable is that it is fully reversable, does not show and uses no new parts, and gives a whole new dimension to a Ric bass. As you dial in more cap you can hear the bass coming alive with more presence (CCW), if you want the traditional 4001 sound turn it all the way the other way (CW)
In between you can strike a nice balance between the top and bottom, it is almost like having a third pickup somewhere in the middle of the neck and bridge pickup.

wim · Post by **wim** » Sat Apr 24, 2004 12:50 pm

hey! I was planning to do the same sort of surgery tomorrow.
Only I planned to unsolder the third pin (to the ground) on the volume knobs and wire them via the capacitor directly to the output.
This way I'd have two bass cut controls and two treble cut controls but no volume (which I don't use anyway)
Almost the same thing as you did.

rictified · Post by **rictified** » Sat Apr 24, 2004 1:01 pm

I considered putting both pickups through the cap and I still might try it, but I don't think it will sound very good like that. I won't get the difference between the two pickup's sounds. I thought this was earth shaking stuff, I guess not huh?
your idea is also interesting, but I like the volumes.

jwr2 · Post by **jwr2** » Sat Apr 24, 2004 1:23 pm

Bob ... I posted last year that someone could wire a .0047 capaciter into a pot and thereby make a bass cut tone control ... I'm glad someone tried it ...

I considered making the neck tone control a treble cut and the bridge tone control a bass cut ...

jwr2 · Post by **jwr2** » Sat Apr 24, 2004 1:37 pm

Bob ... couldn't you just remove the .047 cap for the bridge pickup and replace it with a .0047 cap?

beatlefan · Post by **beatlefan** » Sat Apr 24, 2004 1:54 pm

As in the commercial for Samuel Adams.....

"BRILLIANT"!!!

jwr2 · Post by **jwr2** » Sat Apr 24, 2004 3:52 pm

OK I tried just wiring the .0047 cap in place of the .047 cap and wired that way it rolls off treble and not bass ... and it rolls off less treble than the .047 ... I guess you have to wire it the way Bob said ...

rictified · Post by **rictified** » Sun Apr 25, 2004 1:18 pm

Jeff, that's the layout I have, the neck tone is the treble control for both and the bridge tone is the bass tone (cap control), I just called them bass and treble because that's what they say on the knobs and figured it would be less confusing that way. I do not have the talent of making something simple sound simple, in fact I do the opposite usually.
Let me know your results if anyone tries it, I really like it a lot. I haven't gotten any shielded wire yet to make it permanent, when I do I'm going to do my round wound bass, there should be quite a change there. I'll look this week, I haven't been able to find any #44 magnet wire yet either.

paul_yan · Post by **paul_yan** » Tue Apr 27, 2004 6:30 pm

Awesome idea, Bob!
Will try that on my '98.

rickcrazy · Post by **rickcrazy** » Wed Apr 28, 2004 12:21 am

Roger that, Bob.

rictified · Post by **rictified** » Thu Apr 29, 2004 12:29 pm

If either of you two guys try it, let me know how you like it. I've been having fun trying different settings. I did it to my 4001 that has the round wounds on it also. So far I've found that I like the cap knob somewhere in the middle. I can get that traditional trebly Ric sound really clearly and add a little more body to the sound with the knob on my RW bass. I've been experimenting with different volumes and different settings with my bass controls, the one constant that I've done is have left my treble pickup on full almost all the time. If I leave it on full and back off the bass PU with the cap on full, I get that low middy tone, then I back off the cap knob until I get a balanced tone, if I want the Ric growl I back off the cap knob even more with the same settings as before, this is especially pronounced with TI's for some reason. I can get a nice scooped sound with a little more bass PU and a little less cap. I am finding it to really be a handy tool for different sounds.

rictified · Post by **rictified** » Sat May 01, 2004 10:00 am

You don't need shielded wire for this mod, makes no difference.
I have also been getting kind of a woody upright like sound with the bass pickup and treble on full and the cap knob somewhere in the middle on my 4003 with TI's. (7-8K pickups)
I can't wait to try this on my fretless.
And with my 78 4001 with round wounds, it gets the classic 4001 sound with cap fully working, you can keep this classic sound and gradually add more low mid to fill it in too, that's what I really like about this mod. The classic sound stays at least until the knob is somewhere past the middle position, starts to get middy near full. you can balance the bass, mid, and treble perfectly if you like.

paul_yan · Post by **paul_yan** » Sat May 01, 2004 11:59 am

Hey Bob,
Forgive my ignorance...Is it possible to make the treble pickup's tone control act like this?

Clockwise: no cap
Counter-clockwise: capped

I suppose the ROS still functions after this mod?

paul_yan · Post by **paul_yan** » Sat May 01, 2004 12:44 pm

Just to make sure, Bob...in step 6, "...The left hand lug should have nothing attached to it." Is it the upper-most lug of the treble tone control (top-right pot) in the pic?

admin · Post by **admin** » Sat May 01, 2004 1:05 pm

Paul: A picture is worth a thousand words and even less soldering. It would be nice to have a photo of the complete circuit such as this as a model.