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.
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...