What's the effect if i change potensio of IBZ EQB 3S preamp ?

[ferdianadek5]

Hello everybody

i wanna change value of my preamp's potensio, i have standar EQB 3S preamp, i wanna change value like bartolini MK1 or Bartolini NTMB

this is the potensio value of EQB 3S
Pots Volume - POTENTIOMETER 25K-B/SOLID
Pots Balancer - POTENTIOMETER VOL/500K/SOLID
Pots Bass - POTENTIOMETER 100K-B/SOLID
Pots Middle - POTENTIOMETER 100K-B/SOLID
Pots Treble - POTENTIOMETER 20K-B/SOLID
Switch Tone selector - SWITCH 2-WAY TOGGLE BK

i wanna decrease the value of :
bass, treble, mid become 50K
Volume still 25K
Balancer become 250K

this is the wiring of EBQ 3S, Bartolini MK1, Bartolini NTMB


EQB 3S


Bartolini MK1


Bartolini NTMB

the question is
it's any effect when i change the value of my potensio ?
i wanna change because the sound of my preamp, is domminant treble, the mid and low doesn't loud

so i hope that you can answer my question

Thank you

cheerrs

[line6man]

The preamp will not function properly.

[ferdianadek5]

i need more answer

[line6man]

Originally Posted by ferdianadek5

i need more answer

Equalizers are usually built to function with components of specific values. If you change the value significantly, the behavior of the circuit also changes. This may be true of both the amplitude of the boost/cut, and the functional range of control throughout the rotation.

In any case, changing the pots is not a desirable means of altering a preamp's voicing, and at best, you are looking at the tonality of adjusting the existing pots.

[ferdianadek5]

more answer please

[giacomini]

Originally Posted by line6man

The preamp will not function properly.

Originally Posted by line6man

Equalizers are usually built to function with components of specific values. If you change the value significantly, the behavior of the circuit also changes. This may be true of both the amplitude of the boost/cut, and the functional range of control throughout the rotation.

In any case, changing the pots is not a desirable means of altering a preamp's voicing, and at best, you are looking at the tonality of adjusting the existing pots.

What else do you want to hear(read)?

[SGD Lutherie]

Originally Posted by giacomini

What else do you want to hear(read)?

He wants to hear the answer he wants to hear!

Changing the pot's value will not change the frequency of the control.

That's not the answer he wants to hear.

[Steve Dallman]

The range of each control will not change. The actual control of the tone may be in a different part of the travel with the new pots, but you will not get more or less of the range of each control.

I often use a Baxandall tone control preamp I have built since the mid 70's. I've built a lot of them. It is meant to have 250k audio taper pots. I've used smaller pots and pots as large as 1meg ohm. The preamp performs the same although with the 1meg pots, there is little control at the extremes of the pots.

I've used a lot of Artec preamps that have 50k pots. When switching to stacked, concentric pots, I've subbed 100k pots. The controls work the same.

To change what you want changed, would require component changes in the preamp itself, which wouldn't be possible.

Since your pickups are passive, going to a 250k balance control would roll off high end slightly. THAT might get you closer to what you are looking for. You could add an internal tone trimpot, wiring a standard passive tone control to the circuit on the output of the blend/balancer control (yellow wire.) Perhaps a 500k trimpot in series with a .01uF cap, wired from yellow to ground. Roll off the treble you want, and close up the cavity.

[SGD Lutherie]

Originally Posted by Steve Dallman

I've used a lot of Artec preamps that have 50k pots. When switching to stacked, concentric pots, I've subbed 100k pots. The controls work the same.

I've done the same thing with the same results.