Switched to 250k...

notbillcosby

I've had an AVRI Jazzmaster for several years. It was never one of my most-played guitars for a variety of reasons, but mostly because of the shrill ice-picky high end that i heard through every single amp I played on. I decided I wanted some Antiquity II's, but needed to let the initial blow of spending the money on a fairly high end guitar wear off before spending MORE money on it. It took a back seat for a long time.

I'm a huge huge Danelectro fan (90s reissues rule, haters.) and decided I wanted to take a page from the book of danelectro and make a wooden bridge for the Jazzmaster. So I did! I used a scrap of mahogany (WAY too soft.) to make 6 new bridge saddles as a test. It's alright, I'd like to use rosewood and construct it out of one compensated slab and make a new bridge baseplate for it to attach to... but whatever. My point with this exercise was to tame the ice-picky high end. It really didn't work; more than anything, it just changed the attack and sustain properties, but not so much the tone itself. So I dug a little further.

Why the hell does the brightest guitar in the world (well, second brightest to the Jag) use 1 Meg pots?! I'm not an electronics pro by any means, but I know that higher value pots let more treble through. So I decided to swap them out for some CTS 250ks I had laying around. After some struggles getting thigns to fit back in without grounding out on the shielding, it works! But...

I don't notice a huge difference between 1 megs and 250k's!! I'm completely shocked. The rhythm circuit still sounds more dull and subdued (is that a 50k tone pot?) which is surprising to me. I expected a HUGE night and day difference when knocking those pots down to 1/4 of their previous value, but if anything, it only touched the ice-picky peaks, and i'm not even sure if those are gone as I haven't gotten to play this at higher volumes yet.

Should I have noticed more of a difference, or does this seem about right? Also, the fact that the rhythm circuit is still a 1meg (i think) along with that 50k makes me wonder, which pot's value affects overall tone? What difference would I hear if I had left the 1meg volume in, or the 1meg tone in, while replacing the other with a 250? I know I could try it and find out, but it's a hassle and you guys might just tell me 😀

vastrange

notbillcosby said:
I've had an AVRI Jazzmaster for several years. It was never one of my most-played guitars for a variety of reasons, but mostly because of the shrill ice-picky high end that i heard through every single amp I played on. I decided I wanted some Antiquity II's, but needed to let the initial blow of spending the money on a fairly high end guitar wear off before spending MORE money on it. It took a back seat for a long time.
I'm a huge huge Danelectro fan (90s reissues rule, haters.) and decided I wanted to take a page from the book of danelectro and make a wooden bridge for the Jazzmaster. So I did! I used a scrap of mahogany (WAY too soft.) to make 6 new bridge saddles as a test. It's alright, I'd like to use rosewood and construct it out of one compensated slab and make a new bridge baseplate for it to attach to... but whatever. My point with this exercise was to tame the ice-picky high end. It really didn't work; more than anything, it just changed the attack and sustain properties, but not so much the tone itself. So I dug a little further.
Why the hell does the brightest guitar in the world (well, second brightest to the Jag) use 1 Meg pots?! I'm not an electronics pro by any means, but I know that higher value pots let more treble through. So I decided to swap them out for some CTS 250ks I had laying around. After some struggles getting thigns to fit back in without grounding out on the shielding, it works! But...
I don't notice a huge difference between 1 megs and 250k's!! I'm completely shocked. The rhythm circuit still sounds more dull and subdued (is that a 50k tone pot?) which is surprising to me. I expected a HUGE night and day difference when knocking those pots down to 1/4 of their previous value, but if anything, it only touched the ice-picky peaks, and i'm not even sure if those are gone as I haven't gotten to play this at higher volumes yet.
Should I have noticed more of a difference, or does this seem about right? Also, the fact that the rhythm circuit is still a 1meg (i think) along with that 50k makes me wonder, which pot's value affects overall tone? What difference would I hear if I had left the 1meg volume in, or the 1meg tone in, while replacing the other with a 250? I know I could try it and find out, but it's a hassle and you guys might just tell me 😀

i'm not an electronics pro either but..... you can change the 1 meg pot to be used as a 500k pot by placing 1 meg resistor in parallel with the pot. Potentiometers are (variable) resistors and the higher the pot resistance value, the less high frequencies are attenuated as they restrict the flow of electric current.

Yes reducing pot resistance will only restrict high peak frequencies.

Tone control pot value doesn't matter much because rolldown can be adjusted by changing the capacitor value. Caps are like filters which filter how much treble bleeds to ground.

I think if you want a less bright jazzy you just roll down the (1 meg) tone and volume pots.

Hope this helps man.

Earth

The resistor trick only works if the pot is on full. Then the resistance is halved.

In other positions the resistance varies.

notbillcosby

So, there's really that little tonal difference between a 250k and 1meg pot? It seems silly that everyone is so adamant about using 500ks for humbuckers then... I couldn't imagine that it really makes much of a difference if I can barely hear a difference between 250s and 1megs. I've got a box built with a few different tone circuits and a bunch of alligator clips and a toggle switch, so i can mix and match pot and cap values and do A/B comparisons... I've got an old junko guitar that I'm stuffing one single coil, one humbucker, a toggle switch and an output jack into, so I can use the box as the tone controls and see what difference it makes. Long story short... I just need to finish that up so I can hear for myself.

Earth

Using 250K and 1,000k (1Meg) is a #### ton difference!

Its day and night difference.

Who said theres no difference? They are an idiot! 250k is like a warm blanket and 1Meg is like an ice pick to the ear.

notbillcosby

I could hardly notice a difference after I replaced the 1 megs in my JM with 250s! The rhythm circuit was untouched, and while I know that has a 50k tone pot in it, I didn't expect that circuit to STILL sound darker than the lead with the 250s...

Earth

Do an on the spot A/B with two JMs, one with 250k, one with 1Meg, there's a huge difference.

notbillcosby

Yeah... I think I'm the only person I know that has a JM though. No AB for me!

Earth

You can make a A/B box with a toggle switch to flip between 250k and 1meg, you will instantly notice a difference.