unet
rah - sick
Join date: Oct 2008
1,372 IQ
#1
<blue box build : mods thread!>
So I want to mod the MXR blue box to :

1. have an octave on/off toggle switch. ie. use it as a regular fuzz and be able to switch the octave in/out.
Quote by seljer
the "Blend" control already allows that. All the way counterclockwise its just fuzz, no octave. If you want to add a switch to do it, make the switch disconnect pin 1 of the blend potentiometer.


2. not have a volume drop
option 1. Clip the c11 capacitor (the one connected in parallel with the blend pot). This is c9 on the tonepad layout. Warning : This changes the tone of the blue box quite a bit, so try it before you permanently clip it!

option 2. Add a booster circuit after the blue box to increase it's output. (SHO, LPB etc are fairly small and simple circuits)

3. be able to have either one octave down or two octaves down
Connect a switch between pins 1 and 13 of the flip flip



4. have a "fuzz" control
----


Other reported mods :
100K Linear pot in place of the 50K blend makes it sound "deeper and doomier"


Vero layout : http://www.sabrotone.com/wp-content/uploads/2011/09/BlueBox.gif

Schematic : http://www.tonepad.com/getFile.asp?id=73


Can you guys think up any more mods we can add to this?
Also, if you have any solutions to the unanswered mod questions or any mistakes/improvements to make for the ones I've put up, please post them here and I'll add them to the OP.
Last edited by unet at Oct 28, 2012,
Sid McCall
(Actually, I'm Scott)
Join date: Jul 2006
2,713 IQ
#2
I'm sorry I can't help, but I am incredibly curious how to pull this off. I'm sticking the thread and hoping for some answers!

There's a great blog, tagboardeffects dot blogspot dot com, and the guy |v|ark might be able to help you out. He's really sharp and really quick to respond to questions.
Telecaster - SG - Jaguar
Princeton Reverb, Extra Reverb
P-Bass - Mustang Bass
Apogee Duet 2 - Ableton Suite
seljer
UG Resident
Join date: Apr 2005
1,380 IQ
#3
Err, the "Blend" control already allows that. All the way counterclockwise its just fuzz, no octave. If you want to add a switch to do it, make the switch disconnect pin 1 of the blend potentiometer.
Sid McCall
(Actually, I'm Scott)
Join date: Jul 2006
2,713 IQ
#4
Quote by seljer
Err, the "Blend" control already allows that. All the way counterclockwise its just fuzz, no octave. If you want to add a switch to do it, make the switch disconnect pin 1 of the blend potentiometer.

From what I can tell, the blend is just for the second octave, not the first one. Haven't used mine in a while, so I could be wrong...
Telecaster - SG - Jaguar
Princeton Reverb, Extra Reverb
P-Bass - Mustang Bass
Apogee Duet 2 - Ableton Suite
seljer
UG Resident
Join date: Apr 2005
1,380 IQ
#5
Quote by Sid McCall
From what I can tell, the blend is just for the second octave, not the first one. Haven't used mine in a while, so I could be wrong...


By default, it only does two octaves down. You need to add a switch to bypass the second part of the flipflop if you want one octave down.

I've built the tonepad circuit and it works like so (I added the 1/2 octave switch and I I shoved in a little booster circuitboard after the effect to fix the volume drop issue)
end_citizen
New bird. Flightless
Join date: May 2006
1,581 IQ
#6
Seljer is right. It is a double octave down by default. You use the blend to mix the original signal (although fuzzy) with the double octave. A switch can be added to make it single octave down.
unet
rah - sick
Join date: Oct 2008
1,372 IQ
#7
Great! I updated the OP.

Anyone know where to add a fuzz knob? Or if that's possible?
son of mankind
Registered User
Join date: Feb 2013
10 IQ
#8
Alright so I have a blue newish blue box and I really would like to add the switch to toggle between the two octave. And maybe add a switch to add a more treble effect. Can anyone help me or explain to me how to do this? Preferably with diagrams and pictures if possible? I'm sort of new to this and have been educating myself on the topic. But can't seem to find exactly what I'm looking for.