Can't find schematic of digitech bad monkey

[phazon]

Hello All;

I've been bread boarding some distortion/over-drive pedals and have decided to create a tube screamer type pedal (big surprise right?).  Thing is, I do like the Digitech Bad Monkey pedals because instead of a simple treble roll-off tone knob like most tube screamers, they have the active(?) bass AND treble knobs.

Search as I might, I can not find a line diagram schematic of the Bad Monkey circuit.  I have found circuit board layouts, but not the schematic.  I somehow do not have permissions to download any attachments to responses on this forum, so if anyone can send a URL/link to a page that shows this schematic, it would be GREATLY appreciated.

Since I am really just after the tone portion, if anyone has an idea of how to simply add the bass and treble control to a regular TS9 circuit, that would be equally grand.

Cheers

I am wondering if I can add the tone portion of the following circuit at the end of the a tube screamer type circuit, just before the output, like this one was done...?...
http://i2.tinypic.com/t82kp4.gif

[Fndr8875]

i looked for about 20 min and couldnt find anything either, i had a dod or digitech pedal i was trying to mod a while back and spent days looking for a schematic and never could find it.

http://www.tdpri.com/threads/new-bad-monkey-ok-what-am-i-doing-wrong.178625/


IDK if this helps i didnt go through all the pages but there were some pics and discussion about how the pedal works, also several ppl said to just get a timmy.

[Ice-9]

EDITED FOR MY ERROR

SORRY -I was thinking of a different pedal, the BAD MONKEY has its first tone control (HIGH) is the same type as the TS808 (different values) and the second tone control (LOW) is also similar to the TS808 type but with a gyrator for shaping the tone. Hope this helps a bit more.

[phazon]

Yes, that does help...a little...but I don't know what "gyrator" is.

Can you link a similar circuit that has this?

[Ice-9]

yeah, check out R.G. page in the link below. It has examples of the standard TS808 type tone section along with a Gyrator based type. The gyrator bit of the circuit is circled with a dotted line, you should be able to recognise the differences using the diagrams. Great detailed explanations are there as well.

http://www.geofex.com/article_folders/eqs/paramet.htm

Also here, http://www.muzique.com/lab/gyrator.htm the part in the diagram that is marked as (IN) would connect to the wiper of the TS808 type tone control replacing the existing resistor and capacitor. Just as an example.

[slacker]

The Bad Monkey is apparently similar to the DOD FX51, there's a schematic for that in this thread http://www.diystompboxes.com/smfforum/index.php?topic=80440.0 it certainly uses gyrators in the tone section so you could try copying the tone controls from that.

[Fndr8875]

idk if this applies to bad monkey but the DOD pedal i had and a bunch of them use all w100k pots, jrc4560d ics and also the cde4009 chip. I got the one i had at a pawn shop for like 10 bucks, it also had like 5 j201 fets and 4 or 5 5088s, know its buffered and not true bypass so that adds to it parts wise, again dont know if that helps but all those dod/digitech pedals from that time period that ive seen gut shots of use all w100k pots, so that could matter as far as the tone shaping portion of the circuit.

[Ice-9]

idk if this applies to bad monkey but the DOD pedal i had and a bunch of them use all w100k pots.

Yeat both the tone control pots in the Bad Monkey are 100kW


The audio path basically is----

transistor buffer--- gain stage feedback loop diode op amp----- ts808 type tone control---- tone control 2 gyrator ----volume control pot--- output buffer...

So basically same as a tube screamer with a second tone control section. Of course the component values differ to the tube screamer.

There is a cabsim type filter circuit tagged in as well for mixer output but I have ignored that for the basic topology of the pedal.

[Ice-9]

The CDE4009 and j201's will all be the byapass circuit. Possibly one J201 as the input buffer

[J0K3RX]

I believe it may have a lot in common with this..?
https://forums.rgc.ro/uploads/monthly_03_2010/post-7179-1270059496.jpg

[blackieNYC]

I believe it may have a lot in common with this..?
https://forums.rgc.ro/uploads/monthly_03_2010/post-7179-1270059496.jpg

Holy Digikey! This one seems like an awfully high parts count for "blues".

[J0K3RX]

I believe it may have a lot in common with this..?
https://forums.rgc.ro/uploads/monthly_03_2010/post-7179-1270059496.jpg

Holy Digikey! This one seems like an awfully high parts count for "blues".

Yeah, it does have a few parts.. The name can be a little misleading, I actually like the screamin blues as a straight up OD pedal more than the bad monkey. Keep in mind, everything after R72 on the SB schematic is a terrible attempt at a speaker/cab simulated output..  Bad monkey has the same lame speaker sim out also. 

[Ice-9]

I believe it may have a lot in common with this..?
https://forums.rgc.ro/uploads/monthly_03_2010/post-7179-1270059496.jpg

Holy Digikey! This one seems like an awfully high parts count for "blues".

Yeah, it does have a few parts.. The name can be a little misleading, I actually like the screamin blues as a straight up OD pedal more than the bad monkey. Keep in mind, everything after R72 on the SB schematic is a terrible attempt at a speaker/cab simulated output..  Bad monkey has the same lame speaker sim out also. 

Thing to note with that circuit is the fact a lot of those discrete components are actually making up a discrete dual op amp (similar to the boss bd2).

regarding the tone control sections, they are not the same as the bad monkey. the first tone as I said ealier is the same type as a tube screamer but with different values, the second is similar to the screaming blues circuit although the gyrator is based around a bjf transistor not an op amp.

I will have a look on my HD as i'm sure I have the diagram somewhere.