My Hacked BMP tone control

[CodeMonk]

I've been messing around with tone controls for the past few weeks. Vox, Fender, and Marshall, variations, and others as well.

Last night I took a crack at modding the BMP tone control. Not the first time I have done so.

Here is what I came up with.
Haven't bread-boarded it yet so I don't know how it sounds.
And ignore the +9V there. I'm adding a gain recovery stage later.
Hopefully I'll get a chance to bread-board this later today.

I've also included some screen shots from Duncan Tone Stack Calculator So you can see what it (Hopefully) sounds like.

I'm sure this has been done only about a million times before, but this is my take.
Bits of this were inspired by Jack Orman. http://www.muzique.com/lab/tone3.htm

VR2-A, and VR2-B are halves of a dual gang potentiometer wired opposite one another.
LAYOUT:




TRACE:



DUNCAN IMAGES:




FULL MID RANGE:

[pinkjimiphoton]

nice!!! but.............
you may need to go with a 50 or 100k pot and use tapering resistors....i assume ya want individual control of each mid pot, right?

hit geofex, and read r.g.'s article on the secret life of pots. i think finding a dual ganged 22 or 25k pot is gonna be a real mutha bro..

[CodeMonk]

nice!!! but.............
you may need to go with a 50 or 100k pot and use tapering resistors....i assume ya want individual control of each mid pot, right?

hit geofex, and read r.g.'s article on the secret life of pots. i think finding a dual ganged 22 or 25k pot is gonna be a real mutha bro..

Its a dual gang pot. Wired so one side reduces, as the other side increases.
R1 reduces value while R2 increases value, for example.
But oops...I didn't draw the layout like that. My bad.

And I found some 22K here:
http://www.alphapotentiometers.net/html/16mm_pot_22.html
Requested a quote.

250K gives a nice range for the Tone control.


Edit:
Updated layout:

[WGTP]

How do you post the Duncan Tonestack screen shots?  I have one I have been working on I'd like to show.  Thanks. 

[a soBer Newt]

How do you post the Duncan Tonestack screen shots?  I have one I have been working on I'd like to show.  Thanks. 

My guess would be that its some sort of print screen ?

[CodeMonk]

I just pressed my Print Screen Key (Or "PrtSc"), Pasted in my favorite image editor (Paint Shop Pro, Been using it since Version 0.9 or something. Poor mans Photoshop) then cropped it.
Uploaded to photobucket and put link to the image in my post.

On another note...
I'm not stuck on 22k or 25k. 50k works as well (better actually).

I looked at the Math Helper page and figured I could use a 100K dual gang pot and add a 50k resistor across 2 pot logs 1-2 and 2-3, to come up with 50K.
But isn't that going to leave a dead spots in the pot rotation?
(Haven't tried it yet...just woke up

[PRR]

> pressed my Print Screen Key.., Pasted in ...Paint Shop Pro

PSP 6 and 7 have File, Import, Screen Capture, Setup, "Area, Full, Window"

Set it up on Area F12 Multiple, you can snag several part-screens quickly.

[CodeMonk]

> pressed my Print Screen Key.., Pasted in ...Paint Shop Pro

PSP 6 and 7 have File, Import, Screen Capture, Setup, "Area, Full, Window"

Set it up on Area F12 Multiple, you can snag several part-screens quickly.

Oh yeah. Forgot about that feature.
Very handy.

[crash415]

Try this one
I have this one at the end of my BSIAB II

R1 and R2 are 5.1K resistors with a dual 50k pot.  Wired so that when one is turned down, the other is turned up.  Makes for a nice mid boost/cut.


Note: I have R3 as a 240k pot because I was trying to find a good mid control only.  That pot should be a 250k linear

[CodeMonk]

Try this one
I have this one at the end of my BSIAB II

R1 and R2 are 5.1K resistors with a dual 50k pot.  Wired so that when one is turned down, the other is turned up.  Makes for a nice mid boost/cut.


Note: I have R3 as a 240k pot because I was trying to find a good mid control only.  That pot should be a 250k linear

Looks good.
Thats what mine does with R1 and R2, just different values and curves there.
I'm trying to do a single Tone Pot, with a "Mids Control" pot.
Would like to be able to get that curve with a single gang pot.

Still haven't gotten around to bread-boarding it though
Hopefully today/tonight.

[WGTP]

Thanks.