Bad Monkey, or Mud Monkey?

Foamy · #1 05-07-2009, 04:14 PM

I swapped C22 with a 1uF and C5 with a .22uF. I have almost no highlights. Is that to be expected? It's very dark, and I can get some real nice crunch, but reeeally dark.
Advice? Thoughts?

Foamy · #2 05-08-2009, 08:29 AM

Bueller?

karter2000 · #3 05-08-2009, 01:10 PM

Sorry for not replying earlier,

I did the "indyguitarist mod" which is change C5 to 0.1uf (stock is 0.047uf) and C11 to 1uf (stock is 0.22uf). It's pretty dark as well with those mods. I'm fairly happy with the sound, but I would like to go back into and change things up a bit. I'm going to trace the circuit, and compare it back to a Tubescreamer schematic to confirm what each component does (at least the ones that are not SMD!).

I'm not clear on what C11 or C22 does, but judging from the original value, I'm pretty sure C5 is part of the high-pass circuit on the opamp and clipping diodes. There's a really good article by Jack Orman on that particular part of the circuit:

http://www.muzique.com/lab/fatt.htm

But like I said, I need to confirm the BM schematic. I will post any changes I do here.

Hope that helps,

Lyle

Foamy · #4 05-08-2009, 01:13 PM

Quote:

Originally Posted by karter2000

Sorry for not replying earlier,

I did the "indyguitarist mod" which is change C5 to 0.1uf (stock is 0.047uf) and C11 to 1uf (stock is 0.22uf). It's pretty dark as well with those mods. I'm fairly happy with the sound, but I would like to go back into and change things up a bit. I'm going to trace the circuit, and compare it back to a Tubescreamer schematic to confirm what each component does (at least the ones that are not SMD!).

I'm not clear on what C11 or C22 does, but judging from the original value, I'm pretty sure C5 is part of the high-pass circuit on the opamp and clipping diodes. There's a really good article by Jack Orman on that particular part of the circuit:

http://www.muzique.com/lab/fatt.htm

But like I said, I need to confirm the BM schematic. I will post any changes I do here.

Hope that helps,

Lyle

Thanks. I appreciate it. I was, honestly, not so satisfied. The lows are great, but there is no sparkle or sizzle. I am thinking about undoing it. Like the maroon I am, I did not even try it out as stock. Doh!
Hey, did anyone tell you that you kind of look like Alex Lifeson in that photo?
Anyhow, thanks!

karter2000 · #5 05-08-2009, 01:22 PM

No problem! Actually, back when I used to play guitar I idolized Alex Lifeson...still do, actually.

I used mine stock for a while, and while I really liked the way it sounded, it does cut some bass regardless of settings. That's why I tried the mods. I would sorta like to go back to the way it sounds stock, just with better bass response. Unfortunately, the mid-hump is characteristic of Tube Screamer circuits like the BM. It either works for you or it doesn't.

I'm probably going to C11 back to stock, and try the AMZ Fat Mod as per the link I posted.

Lyle

Foamy · #6 05-08-2009, 06:14 PM

I just put mine back to stock, and I very much like it. Moral of the story? If it ain't broke, don't fix it! I reallllly bought into the hype. I suppose, as always, to each, his own. Anyhow, I think I like this, and it'll be a lot easier to carry around than the E Muffin for those Sunday sessions.

Crystalman85 · #7 05-08-2009, 08:53 PM

By bad monkey, did you mean the digitech bad monkey tube overdrive pedal?...I've heard sound samples of that pedal on the wiki section of this site. it actually sounds pretty cool on bass.

Foamy · #8 05-08-2009, 08:57 PM

Yep, that's the one! And now that I've un-modded it, it sounds pretty good! :-)

karter2000 · #9 05-09-2009, 02:29 AM

Yeah, stock they are fairly transparent...but of course I can never leave well enough alone

.

Tonight I messed around with mine some more. I put C11 back to stock (0.22uf), and removed C5 altogether (no jumper). To my ears, it sounded really, really transparent. I was even able to match my bypassed tone with some tweaking of both tone knobs.

The real fun came when I did some "circuit bending". I put the 1uf cap that I removed from C11, and placed it across the legs of the 0.22uf cap. What I got was a big increase in bass. When I put the original cap 0.047uf across C5, the typical mid-hump came back. When I put a 1uf across C5, there was very little output, and sounded very muffled.

Anyways, I would be interested in seeing what other cap values due, but as said before the BM sounds pretty good unmodded.

...oh yeah, I did also put in a blue LED...very important.

.

Lyle