Digitech bad monkey mods

dangb523 · April 16, 2007, 09:18:37 PM

does naybody kno, any mods for the digitech bad monkey?

Bucksears · April 17, 2007, 08:23:10 AM

I'm curious about this too. Someone somewhere on the Fender Forum had a mod for more mids, unofficially turning it into a Vox-ish distortion, but I don't remember what the mods were.
Anyone?

- Buck

Seljer · April 17, 2007, 08:48:07 AM

does it use regular parts or is it already surface mount? I'm thinking about picking one up (not for modding), they're cheap and they sound pretty good stock too

Tuemmueh · April 17, 2007, 08:57:53 AM

Sadly, most stuff on it is smd ...

MKB · April 17, 2007, 01:22:52 PM

The good news is basically the circuit is a Tube Screamer with a more sophisticated tone stage; it has a dual op amp in the distortion stage that can be replaced as well as the clipping diodes. I replaced the op amp with an RC4558 and added asymmetrical clipping diodes, which was a real help. Also, many of the other TS mods can apply.

The bad news is most of the circuitry is surface mount, even the pots are PCB mount with long shafts. It was HARD replacing the op amp, had to add an external board and use jumpers to connect the DIP8 to the SO-8 footprint on the BM board. It was also very hard to replace the diodes, as both clipping diodes in the BM are actually in a single 3 pin surface mount package. It is hard to replace the gain pot with a larger value as it is a strange model with PCB mounting and a log shaft, i couldn't immediately see how to replace it with a standard shaft mount pot. They also used a lot of ceramic SMD caps that would be hard to replace with better dielectrics. It's a real shame they did this, as a well modded Bad Monkey has the possibility of KILLING a Tube Screamer.

jonathan perez · April 17, 2007, 01:27:49 PM

Quote from: MKB on April 17, 2007, 01:22:52 PM
...a well modded Bad Monkey has the possibility of KILLING a Tube Screamer.

it seems to me a stock one has a pretty good chance as well

grolschie · April 24, 2007, 07:10:25 PM

Is upgrading the caps do-able even though it's SMD? Worth the effort?

I cannot for the life of me find a schematic for the Bad Monkey. It seems that people cannot decide which OD it is based on (or is a clone of).

I am very much liking mine, but it sounds a little boxy at times. I would like to make it even smoother. It seems that a few people out there mod them, but perhaps are keeping tight lipped about what is possible.

Tuemmueh · April 25, 2007, 06:26:59 AM

Quote
Is upgrading the caps do-able even though it's SMD? Worth the effort?

1. yes, 2. no

... in my opinion. Maybe someone will hear a difference, I bet most people won't!

Quote
I cannot for the life of me find a schematic for the Bad Monkey. It seems that people cannot decide which OD it is based on (or is a clone of).

Like it's been said, it's a Tubescreamer with an active tone-control.

Quote
I am very much liking mine, but it sounds a little boxy at times. I would like to make it even smoother. It seems that a few people out there mod them, but perhaps are keeping tight lipped about what is possible.

If you are able to solder some smd, you can mod it like every other Tubescreamer-Clone out there (would guess 50% of all pedals, 90% of all "boutique-pedals"), but it won't be that easy if you aren't into smd-soldering!

grolschie · April 27, 2007, 08:18:12 PM

So making it more like a TS808 is not really viable? I woudn't have a clue which parts to swap.

Alex C · April 27, 2007, 10:09:02 PM

Welcome to the forum, dangb523.

grolschie · April 29, 2007, 01:17:36 AM

Quote from: grolschie on April 27, 2007, 08:18:12 PM
So making it more like a TS808 is not really viable? I woudn't have a clue which parts to swap.

Egad! I opened mine up. It seems that the only easy components to replace are the caps. They are green caps so should sound ok. I am guessing most mods, involve swapping resistors, not caps? How the heck does one replace SMD resistors?

wampcat1 · May 01, 2007, 12:48:43 AM

I didn't really spend alot of time reversing it, but at a glance it looked sorta similar to the RC/AC booster type circuit minus the extra diodes.
It is a opamp clipper with diodes in the fb loop though. You may or may not consider that a TS clone.

bw

grolschie · July 04, 2007, 12:51:52 AM

Quote from: dangb523 on April 16, 2007, 09:18:37 PM
does naybody kno, any mods for the digitech bad monkey?

TS808 mods are possible, R52 is the shunt resistor and C32 is the coupling cap after the output buffer transistor Q9. There is no series resistor, but one can be added. The signal forks after Q9 into the coupling cap (normal output) and the amp sim ouput.

D2 is a surface mount dual diode combo. Replace this with clipping diode combinations of your choice.
The TS808 mods are subtle at best. Even removing R52 completely sounded pretty much the same. The stock BM is a winner already.

News:

Digitech bad monkey mods