1 Meg Pots

Travisthedog

Brighter or darker than 500k or 250k?

stickyfiddle

Brighter, especially on a sunny day

Travisthedog

So if I want to tame my Jazzmasters huge brightness (mojo loom came with 1 meg) - dropping to 500k or 250k will help?

GavRichList

So OSG says, yes

Paul_C

yes, I took the 1 Meg pots out of my JM JM sig JM and replaced them with 250k, mostly because the not-great (wound more like a Strat than a Jazzmaster) std. pickups combined with the 1 meg pots could take the enamel off your teeth if you weren't really careful.

I ended up putting some Lollars in too, which were lovely.

Travisthedog

Yeah I have some mojos in mine

Right - time to get the soldering iron out

meltedbuzzbox

Travisthedog said:

Yeah I have some mojos in mine

Right - time to get the soldering iron out

I think the amp plays its part too. Fender amps seem to really make the treble prominent from the 1k pots. 

I notice on my Hiwatt its not an issue. 

Saying this new pots are cheaper than a new amp. 

I think on the lollar website he recommends setting the volume to 8 or 9 on a JM with 1meg pots to take off some of that top end.

Let us know how it pans out, I am curious.

Travisthedog

thats exactly what i have to do!!

Jaded

Nels Cline has 250k pots in all of his vintage Jazzmasters, really does seem to make them a little more friendly. That said, I put 250k pots (well a 250k volume and a TBX tone) in my Jazzuar and it's still really rather bright!

impmann

That's probs got more to do with the TBX - iirc the centre detent is allegedly bypass and then you have a bass roll off going from 5-10 and a treble roll off from 5-0. From my experience, this wasn't very good... Unusual choice in a bright guitar IMHO.

I keep meaning to give 250k pots a try but tbh, if you have good quality pickups (I have Mojos, with a slightly altered winding on the bridge pickup for more warmth) it's not needed. Plus, the tone control will roll off the top if it's too bright, quite nicely, in my experience.

ICBM

TBX stands for Total BolloX .

At the centre detent it artificially strangles the tone by loading the pickup with an 82K resistor in order to make the full-up sound appear to be brighter and fuller - "treble and bass expander", which is what Fender wanted it to stand for - whereas in fact it's brighter and *thinner* than it is with a standard tone control. In a Jaguar it will be even worse than it is in a Strat, probably.

impmann

I couldn't remember the science behind it but I do remember them being... fairly poor. Thanks for that ICBM.

ICBM

You can actually improve them a lot simply by snipping the resistor. Then it becomes a standard 250K/.022uF tone control from the centre notch down, and a 1.25M tone control from the centre notch up - not far off a 'no load'.

jellybelly

I had a similar complait with my other jazzmasters - when it came to build one myself I changed a few things...

- lead circuit with 250k volume and 500k tone plus treble bleed cap.
- rhythm circuit with two 1 meg pots

This meant I could still get the bright jazzmaster rhythm tone if I wanted it but the lead sounds were darker. Sort of opposite to a normal jazzmaster. However since having played it as my no. 1 for about 6 months, I've discovered a few things that I hadn't realised or considered (it really helps having the pots switchable to test this stuff!)

1. The tone pot rolled off is the same as a lower value - no tone difference assuming the same cap is used.
2. Lower volume pots indeed darken things but they also make it less dynamic and reduce output. Think of it as two valve amps - one with loads of headroom and one that's being driven pretty hard and limiting your harder playing, that's te best analogy I can think of. Basically the two 1 meg pots, vol 10 and tone 6 is the same brightness as the 250k/500k with vol 10 and tone 10, with a tad more output and a clearer/thicker sound with more 'air' around the top notes. Whatever air is.

Essentially I use the rhythm circuit, vol 10 and tone 6 for clean and the rhythm circuit for OD sounds as the dynamism is mostly lost and I like being about to control the volume from the guitar. Just a thought/my findings. You may hear something different!!

Jaded

Yep! I used the TBX at the time as I'd stuck humbuckers in the guitar. I'm not sure if it was in a PM or a thread back on the other forum you told me about snipping the resistor, definitely helps but this guitar is just a particularly thin sounding one atm. 

Needs some heavier strings (has a set of .010's atm), a decent bridge with the right radius (has a mustang bridge with the only two different sized saddles atm, so closer to a 9.5" radius I guess) and a steeper angle over the bridge (there's no shim in the neck pocket and it could really do with one).