Crunchbox modification question

[canman]

Hi guys,

I can read schematics but I don't really understand what's going on (aside from voltage divides, etc...the easy stuff).  I built a Crunchbox using this layout: http://tagboardeffects.blogspot.com/2012/02/mi-audio-crunch-box-v2.html and it works perfectly.  Gave it to my brother cuz it sounded REALLY good and it was perfect for his style of music.  I'm gonna build another one this week, but I've been wondering how difficult it would be to add a mids control to the circuit. 

This is the schematic I've been looking over: http://1.bp.blogspot.com/-0zGoV3jSwJs/TyKL3gQsCqI/AAAAAAAAAvs/s1ZwxhpG0WU/s1600/miaudiodistv2rx7.jpg

The mids were VERY present in this circuit, which I thought was pretty cool, but I think it would be cooler to be able to adjust the mids.  Is this gonna be something as simple as adding a trimmer instead of a resistor, or would I need significantly change the circuit?

If it's a fairly easy adjustment, I'd love to hear some ideas, but if it's gonna be pretty difficult to do I'm OK with just doing the layout I did before.  Just thought it would be kinda fun to look into!

Thanks guys!

[roseblood11]

It would be a little more complex, but it should be possible to use the crunchbox pcb, as most of the changes could be done with components that are soldered directly to the pots. Search the web for a Marshall Drivemaster schematic. That's basically the same circuit, but with a TMB tone control. The other difference between both circuits is the different gain of both stages.
Maybe there is a vero layout for the drivemaster that you could use as a starting point.

Or build a Catalinbread Dirty Little Secret Mk3...

[canman]

Hmmmm...so if I wanted to add the mids control, I'd need to add TMB instead of just a mids control?  Or could I just pull the components for the mids (based on the link below) and then send the signal to output and just bypass the treble and bass controls?

Here's a schematic for the Drivemaster for reference: http://www.aronnelson.com/gallery/main.php?g2_view=core.DownloadItem&g2_itemId=44736&g2_serialNumber=2