changing the tone pot 250k/500k

[basvincent]

my "problem" is this:

my mm axis SS piezo has a very bright sound, actually too bright. playing adjusting the tone knob isn't working well enough, as well as the treble or presence on my amp.
I've heard about changing the tone pot to 500k, assuming it's a 250... (is it 250k, b.t.w.?) or adding resistyors parallel with the pot...
I don't know how to describe the sound, it's glassy and too much presense...

 

[smk5150]

AFAIK Super Sports have 500k volume and tone pots. You can try using 250k volume pot.

Are you sure it's the guitar? Have you tried other amps? I've had axis SS for a while and the tone was rather thick and dark sounding. Not bright anyway
Maybe something's wrong with piezo/mag switch and it mixes piezo signal with magnetic pickups?

 

[basvincent]

The switch is ok.
I use a Marshall superlead 100Watt, modified by Peter van Weelden (www.vanweelden.com) and use a Koch 412 cab with Jensens...
I'll try changing the tone pot, but will wait a few days for other replies.
but thanks anyway!

 

[SteveB]

have you tried sending the piezo output into an acoustic guitar amplifier or a full-range sound system such as a PA?

The piezo sound is a bit glassy, I think that's normal, but the output of the piezo really isn't ideal for a Marshall.

Try it through a PA system so that the full range of frequencies can be properly reproduced.

 

[basvincent]

it's not the piezo, the piezo is just fine...

 

[Antoine]

...........I've had axis SS for a while and the tone was rather thick and dark sounding. Not bright anyway

Totally agree with this !!!

 

[beej]

Not 100% sure, but I'd wager the pots are 500k. (Or should be, anyway - unless it's been rewired.)

Decreasing the resistance (from 500k to 250k) will will darken the pickups, increasing it will do the opposite. What you're doing is shifting the resonant frequency of the pickups by changing the constant load on them. If you're going to do it, you might as well change both the vol and the tone control to 250k's.

The downside is that you'll also be slightly reducing the output and dynamic range of the pickups by doing this. Not the end of the world if you like the sound, but worth mentioning.

Another option (an easier one) is to try different capacitor values. Using a larger cap on the tone control will change the amount of high-end you can roll-off. Also, you can try a capacitor at the output of the volume control- the effect is like using a higher-capacitance cable and will give you less highs. (Using a low-cap cable will give you more highs, it's ideal for single-coil equiped guitars but sometimes not as ideal for HBs where you want a lot of midrange).

Lastly- if this happens only when you're dialing back your volume control - but not while it's wide open - then you could use a capacitor and resistor at the output of the volume control to prevent treble roll-off at low volumes. (I'm not sure if your guitar is wired up with this or not.)