DiMarzio/CTS Custom Taper Pots

V8

Just finished a 'upgrade' of the pots in my Hofner P-bass. Coupled with a long overdue re-wire it was time well spent.

This is the third time I've put soldering iron to internals of this beastie - the first was a initial nasty setup with a original parts I got with the bass (not great), then a pickup upgrade (Schaller Pbass pup, clone of the classic Dimarzio Split P pickup) I did a while back didn't get me closer to the tone I was looking for.

So after a load of procrastinating, Santa finally brought me some decent pots. And in his genius, he got 500k DiMarzio's (replacing the 250k alpha pots). P.s. Dimarzio's are (from my reading) are re-branded CTS pots.

https://www.musiciansfriend.com/accessories/dimarzio-500k-custom-taper-split-shaft-pot

As the pot value's have changed AND I've changed the wiring slightly - It's impossible to say if the quality of the pots affected the tone...logically it shouldn't. But, the 500k's let more top end through and I've changed the wiring a touch which have had a definite (for me, positive) effect.

The custom taper (80/20) is likely a acquired taste - I really like the taper for the tone pot. 1/8 turn is halfway between the previous 250k's and the 500k's, a 1/4 turn is sounds similar to the 250k pot fully open. I'm a fan.

On the volume pot, I'm less convinced for this bass. It rolls off quite suddenly compared to the tone pot and the (linear CTS) volume pot on my strat. That said, I hardly ever roll off vol on the bass - 99.9% I'm working the tone knob. I'd probably be better off with a kill switch than a volume knob...but aesthetics ?

Overall money well spent, these CTS/DiMarzio's are a absolute pleasure to work with. Those little spacers and bits are all in the box and space perfectly for any knob I tried. Soldering onto it is sooooo much easier than others I've used.

The amusing part. The pots cost 60% of what I paid for this bass...

wern101

I will also be installing Dimarzio 500k pots in my strat, with humbuckers of course. Not sure the model I have. It reads 'W1' on the pot itself? Long shaft and bits and pieces included. (I tossed the packaging) Anyhoo, picked em up for R50 each at our local store. Couldnt say no. ?

V8

wern101 Anyhoo, picked em up for R50 each at our local store

Lordy...that's cheap. Like below cost cheap! I forked out R135/ea...

Google the pot code, it'll tell ya the deets. If the 500k is preceded by a 'A' it's audio taper, a 'B' is linear and I didn't notice the custom taper ones having any special code on them.

wern101

V8 Lordy...that's cheap. Like below cost cheap!

I know! Which is why I couldn't say no. I think it may have been old stock. Dunno.

The only reference to the 'W1' on the pot that I can find reads that these are PU Switch contact points on the internal JTV-89 PU Switch PC Board. (This on a forum that has got nothing to do with Dimarzio tone pots) ?

So I really don't know - since I chucked the packaging months ago. Not that I think there were any clues either...

V8

During the googling of the pots prior to buying - I did read that DiMarzio pots were re-branded CGE manufacture and later changed to CTS manufacture. From what I read, those you got there are CGE era pots.

Found this post : https://www.thegearpage.net/board/index.php?posts/7721029/

But I gots NO idea on what the W1 code means...internet's failed us today. ?

wern101

V8 Thanks! Saw this: "and the axle of the wiper is visible through the back" Definitely mine! So this is a CGE Pot then - although, the back is quite flat.... hmm. We'll see what they do. As long as they work I am happy.

V8 internet's failed us today

Yup. Who knew that was possible. ?

OD1

Do you need a 250k pot for bass, sorry I dont play bass - but you know you can change the 500K pretty easy with a resistor if you need a 250k.....you can take a 500k resistor and connect it to the 2 outer lugs of the pot, or you can take 2 250k and connect each outside lug to the middle (wiper) lug, apparently this helps the taper but havnt tried that method.

You can also put a resistor in the guitar wiring so that the pickup 'sees' 250k the same I assume with guitar if you have a 500k and 250k pot for example. Will need to look up a schematic but it should be straight forward to google.

V8

OD1 Thanks for the info - I had that bass opened up yesterday solving a scratch jack (done).

Happy with the pots are they are - 500k's gave me a little more top end. Though I'd still got with a linear taper for the volume.

A good mate is a electrical engineer and guitar/pedal tech - I'll ask him about using resistors to change the curve of the taper, cool idea.

OD1

V8 Yeah I tried a higher value cap on my guitar to cut some highs and that's where my journey started experimenting with caps, resistors and eventually I wired a bass cut pot into the circuit which was one of the best mods I've ever done. Each guitar should come stock with a bass cut pot imo. I don't know how usefull it could be on a bass but hey.....maybe it could work

V8

OD1 y I wired a bass cut pot into the circuit which was one of the best mods I've ever done

Aka a treble bleed? (That is when you roll off volume you don't lose frequencies as one normally would)

On a guitar I'd agree. it's almost essential (unless one always plays 100% vol) - on a bass, I've not yet found myself missing it. I hardly ever touch the bass's vol pot, If I need dynamics I'll usually use a pedal and bump the gain/vol there.

OD1

Yeah the treble bleed mod is done for guitar on the volume pot (input lug and wiper with a resistor and cap or combination of them) and the bass cut can either be a passive on/off circuit via a switch, or you can wire a extra bass cut pot into the normal volume and tone pots, then you basically have a volume, tone and bass pots - found the bass pot really usefull.

Looks like this: