WTB low reading 250k log pots. 220k ish SORTED THANKS

Mike58 · May 2020

Hi
looking to buy a pair of low reading 250k log pots, ideally unsoldered for a project rewire.
So if you have any pots that read 220-235k , I could really use them.
Need to be CTS size, small pots no use.
Let me know if you have a pair, I can either swap you with good reading pots or buy them.
cheers
Mike

ICBM · May 2020

Any particular reason why? The exact resistance is almost never critical, which is why they're not made to tighter tolerances.

prowla · May 2020

One way to fudge it is to put a resistor across the terminals.

roman_sub · May 2020

ICBM said:

Any particular reason why? The exact resistance is almost never critical, which is why they're not made to tighter tolerances.

Not quite true, 480k pot can noticeably alter a pickup voicing vs 530k pot!

ICBM · May 2020

roman_sub said:

Not quite true, 480k pot can noticeably alter a pickup voicing vs 530k pot!

Have you actually compared that properly using switching?

You might be surprised.

roman_sub · May 2020

ICBM said:

roman_sub said:

Not quite true, 480k pot can noticeably alter a pickup voicing vs 530k pot!

Have you actually compared that properly using switching?

You might be surprised.

I have, I recorded same guitar and same riff (near as), replaced the pot, and immediately compared. Same goes for 220k vs 280k pots.... I measure all of mine and try to calibrate to each guitar + pickup. But that's me...

ICBM · May 2020

roman_sub said:

I have, I recorded same guitar and same riff (near as), replaced the pot, and immediately compared. Same goes for 220k vs 280k pots.... I measure all of mine and try to calibrate to each guitar + pickup. But that's me...

Noticeable difference, or just marginally detectable?

I did some direct-switching tests using extra resistors to change the effective pot resistance and a switch so I could take them in and out while actually playing. The smallest difference I could reliably hear was about 25% below the original pot value and 33% above - sitting right in front of the amp with the speaker at ear level. So I would be very surprised if a 10% variation actually mattered.

For the OP - if you want lower values, just add a resistor in parallel with the pot as prowla said. To get 220K with a 250K pot you need 1.8M, for 235K you need 3.9M.

roman_sub · May 2020

I could hear that 560k was sounding too bright with the bridge pickup on a LP-type guitar, 500k felt a bit flat... magic number was around 530k, for that guitar, in that application... unless it’s a JB, in which case 300k pots are the way to go!

similarly with a dark voiced neck single coil, a pot that read 313k sounded perfect but it developed a problem... the replacement of 280k wasn’t as good. Somehow deflated and less focused.

with some pot designs it’s possible to open it up and carefully scratch at the resistive carbon strip to increase resistance.... That’s how I got mini-Humbucker + bridge single Tele sounding best with volume pot reading around 280k, no load tone (and a 80nf treble bleed, whilst we’re at it!)

but then you get into taper, and how it behaves when you turn down the pot. Whilst it is indeed possible to reduce a 250k pot via a parallel resistor (look online parallel resistance calculators), that will change the pot taper. Ok if linear already, but screws up log tapers... but you won’t care so much if you don’t tend to use your volume pot.

for the record I think capacitor material doesn’t matter, only the actual capacitor value does.

Volume pot resistance affects pickup loading and resonance - whether you can hear it will likely be situation dependent... for example, on a normal single coil Strat that usually has 250k nominal pots, I’m sure I couldn’t hear much, if any difference between 480 and 550k pots, both would probably be far too bright.

However, IME, its possible to subtly tweak pickup response via pot value change if its not quite doing it for you.

i should stress it IS fairly subtle, and I use fairy specific conditions to test my guitars. To put in perspective, I would say the impact is less significant than changing the pickup height.

ICBM · May 2020

roman_sub said:

Whilst it is indeed possible to reduce a 250k pot via a parallel resistor (look online parallel resistance calculators), that will change the pot taper.

Not if you put the resistor in parallel with the whole pot track, if you're just trying to change the overall loading on the pickup.

If it matters, the guitar I did the testing on was a Historic Les Paul Junior with a stock 500K pot that did actually read very close to 500K. (I can't remember what, but something like 508K.) I used resistors in parallel with the whole pot to lower the value, and in series with the ground end to raise it, since I was only interested in the effect of the loading - with a mini-switch hanging out of the back so I could add or remove it while actually playing and a note or chord was sustaining.

I have to admit to being surprised how big a change was necessary for it to be clearly audible.

Hence the question to Mike58 - and with apologies for hijacking the thread somewhat

.

Mike58 · May 2020

Thanks for all the replies, I’m simply doing a partial rewire of a Brian May red special, whose original pot values were 220k ( but did Brian and his dad measure them!.
?..!!)
So for fun I thought I’d try to source a pair close to that value.
ive been down the pot rabbit hole on a Les Paul of mine and eventually ended up with ( horror music plays...) 300k Lin vol pots as they gave me the sound I wanted.
This is a far simpler project, I’m not chasing tone, just having fun.
For the total anoraks in the room, my original set of Burns Tri-Sonic pickups on my 1968 Burns Baldwin Double Six guitar had ..... 100k vol pot, and the neatest instrument wiring ive ever seen.

https://photos.app.goo.gl/NmruQceiAC4yMAUR7

ICBM · May 2020

Well if you'd only said earlier!

Do you want a genuine 1960s RS/Bulgin jack too? I have one of those

.

Mike58 · May 2020

No thanks
just pm me your PayPal and I'll get the 220s from you
thanks
mike

Howdy, Stranger!

Categories

In this Discussion

Become a Subscriber!

WTB low reading 250k log pots. 220k ish SORTED THANKS

Comments