Rickresource Rickenbacker Forum

I've noted before people's comments (particularly Jeff's) re the pots on 4001/4003 basses. I had a look at the pots on my '72 and CS last night, and couldn't see anything on either that identified whether they were 500k, 250k, or anything else for that matter (however as a non-tech head that doesn't necessarily mean anything).

I've been thinking of changing out the pots on my CS to see if I can get a more "vintage" sound (I've recently put a cap in which hasn't made a huge difference to be honest). Any thoughts/advice would be appreciated.

Most Rick pots, whether CTS or other mfgrs, bear a combination code. The entirety is sometimes obscured by solder, but some parts of it are standard and (for about 98% of the pots out there) must be standard. The rest is optional.

The first three digits are the manufacturer code, followed by a hyphen, then there are digits representing the month and year it was made, then after that are the optional codes. Usually, there is an alphanumeric denoting the taper, and another alphanumeric denoting the value. "1M" means 1000 kilohms, or 1 megohm. "250" denotes 250 kilohms, and "500" denotes 500 kilohms.

If your pots do not have this, never fear. You can accurately measure them by unsoldering either end of the three lugs on the pot, then measuring the purely-resistive impedance with a volt-ohm meter (VOM) across the outside pair of lugs (do not touch the center lug). Then, resolder and you are done.

Others have posted links for which mfgr made the pot based on the first three digits, but for your issue that is not important right now. You are interested in how to determine the value of the pots in YOUR bass, right?

Oops, double post. Peter's server is running SLOWly right this second

It took me a while to figure out the difference between 250k 500k and 1000k ohm pots ...

the first bit of information I got was here ...

http://www.stewmac.com/shop/Electronics,_pickups/Potentiometers_and_push-pull_pots/Potentiometers_and_Push-Pull_Pots.html

then the next bit of information I got was the Rickenbacker schematics that showed the volume pots were 250k ohm and the tone pots were 500k ohm ... the current schematic on the Ric web site shows the current configuration of 330k ohm volume and tone pots ...

then the third bit of information was an email from John Hall who told me that in the 60s, 70s, and 80s Ric used 250k ohm volume and 500k tone pots ... in 1990 Ric switched to all 250k ohm pots in the 4000 series basses ... then in 2005 or 2006 they switched to 300k ohm pots ... (and John thanks for that info)

Then I finally understood why certain basses sounded the way they did ... I had wondered why my 1989 4003s5 was so much brighter than my 1990 4003s5 bass ...

pots have a big impact on the sound of the bass ... for instance if your 4004 sounds too dark then put in a 1000k ohm tone pot ... if your 70s 4001 sounds too bright then put in 250k ohm tone pots ... if your 4003 sound too dark then put in a 500k ohm tone pot ...

The .0047 capacitor removes low frequency response from the bridge pickup ... so it really doesn't make the bass brighter it actually removes bass response from the bass ...

there were 3 basses that I experimented with pickups and electronics changes. The first was a 1973 4001 that I got off ebay. It was all screwed up. The pickups were good but it was rewired all wrong. I put in 4 250k ohm pots and no .0047 capacitor. it sounded great. Then I rewired a 1976 Azureglo 4001 for Steve Cooper. It had a pot that turned backwards and a dead neck pickup. I put in a neck toaster and rewired it with all 250 k ohm pots and no capacitor. It turned out to be the best sounding 70s 4001 bass I ever played. Then my 1968 4001 had the original horseshoe pickup and the original toaster pickup. The old pickups were degaussed and weak. They lacked balls. So I left in the pots, bypassed the capacitor, and put in 2 4003 pickups. It still had a ton of treble bite but now it also had 4003 growl. It sounded awesome.

So an easy way to make a v63, C64, or 4001cs sound more like a 60s 4001 is to put in 2 500k ohm tone pots.

Great information Jeff. Very useful. Thanks!!

Let me see if I have this straight:
60's 70's 80's basses= 750k resistance per pickup, brightest sounding
90's basses= 500k resistance per pickup, darkest sounding
'00 basses= 660k resistance per pickup, somewhere between the above
Jeff I think you mentioned in another thread that the 330k pot sounded more like a 500k pot to your ears. I've also heard that pot values are very approximate and should be taken with a grain of salt unless you measure their resistance yourself. It seems obvious that since the 4001 basses were originally meant for flatwounds that RIC used pots to enhance the brightness, and 4003 basses used pots to dampen a bit of the roundwound brightness. I'm guessing RIC went with going with the current 330K tone/vol pots for simplicity and to avoid possible mixups at the factory. I have to imagine that there are a fair number of people who either loved or hated a particular Rick bass simply because the pots were arbitrarily replaced at some point, and they blamed it on the pickups.

Elys & Jeff, thanks for the info, that's fantastic. I'll check out the codes again (yes there are codes on there but not knowing how to read them didn't really help!), although from Jeff's advice it looks like I'll just be changing the tone pots on the CS regardless, just to see what difference it makes. It'll be an interesting experiment if nothing else.

Next question; where best to get the relevant pots?

I will add to what Jeff has stated. He pretty much focused on the tone pots.

"...put in a 1000k ohm tone pot..." "...then put in 250K ohm tone pots..." "... put in a 500k ohm tone pot ..."

Changing volume pots has a huge effect on tone. The lower the resistance a volume pot has the more of the treble it allows to bleed off. Example a 250K pot will give you a warmer tone. 500K is brighter. And 1M is brighter yet.

Jo since the pots are not wired in series you cannot add the resistance. Also there is a capacitor in the circuit that affects the way the tone pot reacts.

Jeff is the man, if it wasn't for his pioneering the 4004 five string conversion I probably wouldn't have tried it, even though mine is slightly different. It's been almost a year since I converted my first one and I'm totally satisfied with the results. I'll probably do a third one at the end of this year and might experiment with different pots in the future.

Quote: "I have to imagine that there are a fair number of people who either loved or hated a particular Rick bass simply because the pots were arbitrarily replaced at some point, and they blamed it on the pickups."

Ya several years ago Sergio and I had some discussions about pickups ... we were trying to figure out why there was such a difference in the basses from 1989 and 1990 ...

and yes using a 250k or 500k or 1000k ohm pot for the volume control will effect the tone a lot ... I discussed tone pots because that is a part of how Rickenbackers got their unique tone was using the 500k ohm tone pot with a single coil pickup ...

pots are not the only factor ... the horseshoe pickups from the 60s were wound to around 6 or 7 k ohms, high gains in the 70s were wound to about 8k ohms, the current high gain pickups are wound to 13k ohms. Then in the 80s some of the toasters and high gains were wound to 13k ohms +/-. The 4003s5 basses had an overwound bridge pickup that was wound to 15k ohms. The 4004 basses have humbuckers wound to 15k ohms and they are wired in series like a p-bass.

Then there is also the way the bass is constructed. The maple wood, the neck through construction, the bubinga fretboard, the conversion varnish, the material used for the nut, the material used for the bridge, the total mass of the bass, the distrubition of the mass of the bass, and the placement of the pickups. All of those factors effect tone as well.

Just out of interest, what do the C-Series have in them? Same as a 4003?

according to this schematic the 4001c64 models have all 330k ohm pots and the .0047 capacitor ...

http://www.rickenbacker.com/pdfs/19524.pdf

but some of them may have been made with 250k ohm pots ...

and according to this schematic the v63 models have the 500k ohm tone pots like the older 4001 and 4003 models ...

http://www.rickenbacker.com/pdfs/19501.pdf

but some of them may have been made with all 250k ohm pots ...

I am not sure about the 4001cs basses ... the one that I played seemed to have 250k ohm pots ...

also to my ear the 330k ohm pots and the 250k ohm pots seem to sound similar

Its probably been asked before,but do all the V63 basses have the 0047 cap or not?
My 99 V63 is a great bass but trying to combine the sound of both pups is difficult. Individually they sound great but try to blend the two as I do on my CS and the result is a weaker sound rather than a meaty combined sound.Whats going on there..is it due to the cap?