Tele pot values.

[Sea Chief]

Hi chaps- long time since been on here: my tele copy's tone pot/ knob didn't do anything until last 1/8 turn when all happened, so assumed I had wrong pot taper. I looked in, & its an A500k. I was expecting to see a B500k (actually B250k I expected).

The vol pot seems right, an even dip in vol over the knob's range. This is a B500k.

I'm very confused as I read that both should be audio "A...k"; so why is my tone pot not right?

thx Sea Chief.

[galaxiex]

Fender Tele's with single coils usually use 250K pots.
Linear or Log, I forget which... I think I've seen both, depends on year and model.

Humbucker guitars usually use 500K pots.

Tele copy? all bets are off, it could have anything.

What brand Tele copy?

[Chuck H]

Well since you had it open you could have put your meter to the pot lugs and tested it for operation. That might clear up the mystery quickly.

Tone pots are usually audio taper. A lot of tele users that are more clean than dirty seem to prefer linear volume pots. YMMV. I like audio taper for both.

Like galaxiex said, value is typically 250k for singles or 500k for humbuckers or a combination of humbuckers and singles. Since strats and teles are widely variable WRT how bright or dark they are it's very common for players to choose the value that suits the specific guitar and their own style rather than what's considered proper for the model.

[Sea Chief]

Ok, understood Chuck, & all what you say chimes with what I read.

But I don't understand why my 'correct' A500k audio taper tone pot, is behaving -precisely- like a wrong linear taper pot. Its behaving -exactly- like a B500k. But its a A500k. There can't be anything wrong with it, if its working exactly like a pot does.

And it can't be because I have a 500k, & I should have a 250k. The only difference between the two is an overall slight difference in brightness so I read. And it just can't be because I have a B500k installed instead, because it says A500k on it.

[Sea Chief]

Fender Tele's with single coils usually use 250K pots.
Linear or Log, I forget which... I think I've seen both, depends on year and model.

Humbucker guitars usually use 500K pots.

Tele copy? all bets are off, it could have anything.

What brand Tele copy?

But it doesn't have 'anything'. It has a vol B500k, & a tone A500k as I said. It says this on the pots.

[Sea Chief]

Well since you had it open you could have put your meter to the pot lugs and tested it for operation. That might clear up the mystery quickly.

How do I do this test, & what can I ascertain from the readings? ie I assume it'll read 0 > 500k. That tells me -only- that it is indeed a 500k (I can tell this by reading 500k on the pot without needing to put a DMM on it).

[Sea Chief]

Well since you had it open you could have put your meter to the pot lugs and tested it for operation. That might clear up the mystery quickly.

Tone pots are usually audio taper. A lot of tele users that are more clean than dirty seem to prefer linear volume pots. YMMV. I like audio taper for both.

Like galaxiex said, value is typically 250k for singles or 500k for humbuckers or a combination of humbuckers and singles. Since strats and teles are widely variable WRT how bright or dark they are it's very common for players to choose the value that suits the specific guitar and their own style rather than what's considered proper for the model.

Chuck- I put DMM on the pots, in situ (Ive no idea if all xyz needs disconnecting to do the test).

The tone pot (A500k) & reads as expected 0 > 70 > 500: at knob halfway.. it reads 70. From what I recall this is correct.

On the vol pot, I get odd readings. 0 > 120 > 0: at knob halfway.. it reads 120 (i ite reads 0 at both sweep extremes).


I have no idea what can be established from this though: is 0 > 120 > 0 to be expected?

[Chuck H]

I have no idea what can be established from this though: is 0 > 120 > 0 to be expected?

Well, on the volume pot you'll be seeing ground at one end and 'through the pickup to ground' (about 7k?) at the other. So I think your reading is normal.

I only suggested testing the pot because it's easy enough to do and you might have discovered something like an intermittent fault in the wiper contact or something. Which doesn't seem to be the case. I'd say you probably are just hearing the circuit behavior then. And I'll guess that your tele is equipped with single coil pickups. If you don't mind the guitar being a tad less bright you will get more intuitive adjustment from an A250k tone pot then. If the guitar is too bright anyway you could try a 250k volume pot too. If you like the action of the linear volume pot then just stick with that.

I'll guess by your reading of 70k at half rotation of the tone pot that you have Alpha pots in there. They are usually fine, and that's what I've been using forever in my guitar, but they do have a less refined taper and end stops than some higher quality options. So maybe try a Bourns A250k "guitar" pot. Available at Mouser. It's more refined 10% taper should help smooth the controls range.

[Sea Chief]

Well I'm totally stumped then. From my experience of electric guitars, the tone should change evenly over the turn of the knob. Not do nothiong.... nothing... nothing... nothing... then last eight of a turn suddenly -everything-. It makes it totally impossible to use, as you searching within mililmetres for the tone. Impractical.

Surely if this is the case, then something isn't correct. That tells me straight off.. that the taper is wrong. But unless Im mistaken, a A500k.. is an audio taper. And I have this as my tone pot. So this is correct, but totally wrong in practise.

How can this poosibly be so??

[Dave H]

What value is the tone capacitor? Try a new 0.047u and a 250k audio taper pot.

[Jazz P Bass]

Nothing was noted as to what value tone capacitor you are using.

Also, what is the value of the pickups.

Can you submit a wiring diagram? (https://www.google.com/search?q=tele...=1555954745097)

[Sea Chief]

Hi there JazzP & Dave H..

tone cap is a .047. I will try 2x new 250k pots, but, I've always struggled with OTT bass (every fender amp seems swamped with it upwards of '3', my tele neck p/u is unuseable alone as its too bassy.. & my champ 5F1 is inherantly bassy too) so Im reticent to add more, or remove some top end swapping out these 500k's. But to find cause of this issue I'll have to.

I have the std tele wiring, with the '50's mod' (one wire shifted over one lug on the vol, from the tone pot). thanks alot chief

[Chuck H]

I've always struggled with OTT bass...
my tele neck p/u is unuseable alone as its too bassy...
I have the std tele wiring, with the '50's mod' (one wire shifted over one lug on the vol, from the tone pot).

Are you regularly or even usually playing with the volume control on your guitar adjusted lower than all the way up? Because that, combined with the 50's wiring would cause:

1) Very bassy tone. The whole circuit operation shifts and the tone filter cuts all frequencies above around 150Hz for most of it's range. Making it seem like the bass is boosted.

B) Very little apparent action from the tone control until it is very close to the end of it's travel. The tone control acts like a weak volume control to all frequencies above around 150Hz until you get to the very end of it's travel and then clips off the higher frequencies.

If this is your circumstances I would suggest you undo the "50's" wiring mod, put the tone circuit back behind the volume control AND get the better quality A250k tone pot. Since you feel the guitar is too bassy now I'd say keep the 500k volume pot (whatever taper you like). Players say a lot about the "50's" mod on the forums, but it's not good for everything and it's not for everyone. Since you may never have tried the guitar with the regular wiring I think you should give it a shot and decide for yourself.

[Sea Chief]

Hi Chuck,

tbh I can't tell any difference having just done the 50's mod! so it was stock up til only y'day. I've never ever been able to use the vol turned down, even an iota.. because.. the bass increaces yet more. So, in 35 yrs of playing, I've never had the vol or the tone at anything but max because both are just completely non-useable even at say 8 its suddenly dark shroud envelops & sounds appalling. I have always found it an utter mystery how players adjust their vols a bit/ down/ up etc, & seemingly have a "pallet" of tone available.. but I cannot. A total mystery. Even having built deluxe reverbs, tweed champs, most recently totally stripped & rebuilt a 70's SF twin reverb.. scratch built guitars up etc, so I'm very far from an amateur player. An enduring mystery.

[Chuck H]

Well if you prefer the brighter sound then a 500k tone and volume turned all the way up is the way to go. But it comes with the consequence of having no tone control action until the end of it's rotation. NOTE: this seems fine to me because the only "useful" setting for a tone control is all the way down with the volume all the way up, where it acts to change the knee of the resonant peak and makes a sort of mid boost. JMHO on that though.

With the volume all the way up the 50's wiring acts exactly the same as the not 50's wiring because those swapped lugs on the volume control are actually shorted together on the volume pot track.