Mid-freq change on Bart pre

[evilgus]

Hi folks,

Was thinking I'd like to change the higher mid-boost frequency (800Hz?) on my new SKB 3005 and wondering whether it's just a simple capacitor change, as detailed in the Bartolini fact sheet for the NTMB circuit. Has anyone done this? Or know how to read the fact sheet? When I open up the bass, will it be obvious whether it has an NTMB2 or NTMB3?

And whilst I'm here, is it possible to add a resistor to the treble pot lugs, to change the range of treble boost? I find it doesn't really open up until near the end, so there's not a lot of adjustment you can play with.

P.S: Also thinking of swapping the 250Hz boost to the down position, as I find that the most useful. Great for giving it a bit of pre-Gib Tobias fatness!

Cheers,

Justin

[JOME77]

Originally Posted by evilgus

Hi folks,

Was thinking I'd like to change the higher mid-boost frequency (800Hz?) on my new SKB 3005 and wondering whether it's just a simple capacitor change, as detailed in the Bartolini fact sheet for the NTMB circuit. Has anyone done this? Or know how to read the fact sheet? When I open up the bass, will it be obvious whether it has an NTMB2 or NTMB3?

And whilst I'm here, is it possible to add a resistor to the treble pot lugs, to change the range of treble boost? I find it doesn't really open up until near the end, so there's not a lot of adjustment you can play with.

P.S: Also thinking of swapping the 250Hz boost to the down position, as I find that the most useful. Great for giving it a bit of pre-Gib Tobias fatness!

Cheers,

Justin

Yep. It's that simple.

http://www.bartolini.net/instruction...ntmb_918_f.pdf

[maurilio]

yes. Try a .22uf in series for the treble.... it moved the frq up high. Just so you know, adding a cap lower the gain (from ~16db down to 12db). I actually like it better that way.
If you want to mod only the boost, add the cap in series on the orange wire.
For the mids the Bart diagr works right (of course). I installed a .22uf to move the frq up around 1.5Khz (I use it only for cut).....

M