Push/pull pot on 4001

[antonius]

HI,

Although I often read the informative posts here (and the facebook group) it's a few years since I last posted anything. So here goes with a new question...

I've had the .0047uF cap bypassed on my 1975 4001 since I bought it in about 1990. It's a great sounding and versatile instrument. However, I usually prefer using both pickups and I've often wished that it sounded as resonant and alive with both pickups on as it does when I just use either of the pickups on their own. I understand that this is due to the comb filtering effect, and that slightly rolling back the volume of one pickup or the other brings back some of that midrange again, favouring one pickup over the other, to create many usable tone variations.

But I can't quite get that vintage both pickups on sound that first attracted me to Rickenbackers as a youngster, and so I unsoldered the wire bypassing the cap to see how it sounded. As expected I can now get that unique classic tone with both pickups on and I'm loving the opennesss and clarity that it brings. But as I may miss the bottom end of the bridge pickup when playing certain styles of music I'm thinking that installing a push/pull tone pot as used on the current 4003 may be the way to go. I understand that the tone pots on my 4001 will be 500K, whereas the push/pull pot that Rickenbacker uses is 330K. Is that correct? What differences in tone am I likely to get by going to 330K? Will it be significantly less bright? I'd like to preserve that character of my bass as far as possible. I live in the UK and I guess this is what I would need, and that it would fit in the 25mm deep cavity: http://www.rickysounds.co.uk/product/330k-with-switch/. Any advice, observations or recommendations would be welcome...

[thx1955]

Hi there,
Reach out to Dane Wilder here on the forum, Dane has a lot of experience with this and can talk in detail to the tonal differences, in addition he builds harnesses for 4001-4003's

I have fitted several of Dane's harnesses going back over the past 5 years, some "push pull" to bypass the cap, and others that are "push pull" to go Mono to RIc-O-Sound on a single output 4001/4003s model
They are very well made and fit easily. Looking at the price of the single pot on the UK site it might be an option to install a whole new harness and keep the original in case you wish to swap back.

Dale has also built Period correct harnesses for my 72 and 73 4001's and as mentioned above I preserved the originals untouched that can be refitted at anytime in the future

[ram]

Dane is the man for sure. Does a great job. Talk to him here or look at his Ebay site:
https://www.ebay.com/usr/aceonbassworks1?ul_noapp=true

[antonius]

Thanks for the replies guys. Much appreciated.

If I were looking to replace the whole harness I wouldn't hesitate to go to Dane Wilder, who certainly knows his stuff. But in my case I'm not looking to pull out all the original parts that are all working fine and producing a wonderful tone, just for the sake of a push/pull pot. After looking more deeply into this, and after reading some old posts here and elsewhere, Including some by Dane Wilder, perhaps I shouldn't just automatically go for the same pot that is used on the 4003, although I'm sure it is a quality component in its own right. Perhaps, to be sure of keeping the tonal character of my bass intact, I need to educate myself on these components and find someone who sells the right quality push/pull pot at 500K. I just did a quick search and there are various sellers online who could probably provide one at a reasonable price. I shall do some more reading...

[espidog]

I need to educate myself on these components and find someone who sells the right quality push/pull pot at 500K.

In terms of what can be found (in the UK anyway) that's the tricky bit. There are perfectly good-quality 500k pots with built-in push-pull switches available, but all the ones I can find online have the splined shaft with the slot in the middle, for push-fit knobs. It is possible to attach a screw-on Rick control knob to this kind of shaft, but first you need to pack the notch with something (to avoid it bending/breaking when screw pressure is applied from one side), and there's also the likelihood that the splined shaft may not be tall enough to properly engage with the grubscrew or even be the correct diameter for a Rick control knob, with the result that your tone knob will rotate a bit off-centre.

All in all, a bit of a nuisance!

[antonius]

In terms of what can be found (in the UK anyway) that's the tricky bit.

Yes, so I'm discovering. Can anyone recommend an appropriate push/pull 500K solid shaft pot that would fit in the 25mm/1" deep cavity of a 1975 4001, and from which seller (not necessarily UK based)? What have other people found to be good? I don't want to buy something that ends up being unsuitable for whatever reason. Thanks in advance!

[aceonbass]

In terms of what can be found (in the UK anyway) that's the tricky bit.

Yes, so I'm discovering. Can anyone recommend an appropriate push/pull 500K solid shaft pot that would fit in the 25mm/1" deep cavity of a 1975 4001, and from which seller (not necessarily UK based)? What have other people found to be good? I don't want to buy something that ends up being unsuitable for whatever reason. Thanks in advance!

There isn't one. The CTS pot fits, but I believe it is of poor quality and inadequately spec'd. I use 500K Bourns solid shaft push-pull pots that are 1" deep.

[antonius]

There isn't one. The CTS pot fits, but I believe it is of poor quality and inadequately spec'd. I use 500K Bourns solid shaft push-pull pots that are 1" deep.

Thank you Dane. I shall have a look for one of these...

[antonius]

I think this may be what I am looking for. Just in case I am missing something can you guys let me know if this is the one? Thank you.

Bourns PDB183-GTR02-504A2

https://www.mouser.co.uk/ProductDetail/ ... FJCw%3D%3D

[espidog]

I think this may be what I am looking for. Just in case I am missing something can you guys let me know if this is the one? Thank you.

Bourns PDB183-GTR02-504A2

https://www.mouser.co.uk/ProductDetail/ ... FJCw%3D%3D

I don't think so, Antony. Looking at the datasheet for that item: https://www.mouser.co.uk/datasheet/2/54 ... 953218.pdf the combined total depth of the pot body and switch assembly is 26.2mm (1.031 inches) - too much for the 25mm depth of control cavity you mentioned earlier.

For comparison, the depth of the CTS pot-and-switch supplied by RIC is roughly 21mm.

PS: Did you get my PM?

[radapaw]

There isn't one. The CTS pot fits, but I believe it is of poor quality and inadequately spec'd. I use 500K Bourns solid shaft push-pull pots that are 1" deep.

Dane, I thought you were using alpha's for your push/pulls? What pushed you to the bourns?

[aceonbass]

There isn't one. The CTS pot fits, but I believe it is of poor quality and inadequately spec'd. I use 500K Bourns solid shaft push-pull pots that are 1" deep.

Dane, I thought you were using alpha's for your push/pulls? What pushed you to the bourns?

RIC also used Alpha pots at one time. I switched because the Bourns are better quality, and don't have the high defective as shipped ratio the Alphas did. Same physical size though. by the way, you have to break the grounding tab off the bottom of the Bourns pots to get the 1" depth dimension.

[jayfbv]

I'm looking for a definitive answer -- will that fit into a thin profile axe like a 4001, an SG, a Firebird, etc.? I vastly prefer parallel humbucking to split coil and there are a ton of thin Gibsons in need.

[Dirk]

It sounds to me like the tone you are chasing is a perfect candidate for using the Rick-o-Sound feature.
Treble pickup through a tube amp or emulation, neck pickup through SS for lows.
Best of all worlds.

Dane's harnesses are excellent and I appreciate having the push pull for getting more classic tones on my old 4003.

Dirk