#1
I've done a bit of research on BMP mods, cause I have one. I like it, but I can't see myself using it with the sustain knob past 1 o'clock, at the most. I'm thinking about removing two of the four clipping diodes to decrease the gain. Has anyone done this? Opinions on this mod? Also, if I remove the diodes, do I need to jumper the holes or just leave em with nothing soldered?
Schecter Gryphon; Ibanez AEG20E
Peavey Rage 158 ; TRAYNOR YCS50
EHX Big Muff Pi; Dunlop CryBaby GCB-95 (modded); MXR M-108 10-band; DigiTech JamMan Looper
#2
adding more diodes can lessen the distortion. If youre not going to be using the sustain much have you tried bypassing the first (clean) amplification stage? and possibly relocate the sustain control to between the two overdrive stages
#3
^That's way beyond my knowledge of how the pedal is built. I did a LITTLE research, not a ton.
doesn't this say that removing 2 diodes makes it louder, less compressed, and less gain?
http://www.student.ru.nl/r.kerkhof/Taas/Mods/Big%20Muff.htm
Schecter Gryphon; Ibanez AEG20E
Peavey Rage 158 ; TRAYNOR YCS50
EHX Big Muff Pi; Dunlop CryBaby GCB-95 (modded); MXR M-108 10-band; DigiTech JamMan Looper
#4
Gain is the measure of difference between the input and output of a circuit. You can measure in current gain, voltage gain etc etc. Just so you know what gain is.....it's not related to distortion.

Removing the diodes will increase gain. The diodes but "stress" on the signal and use up gain. Removing them you will have a higher output and less structured distortion. It will probably sound fuzzier without the diodes.

Do you want to limit the distortion if so there are tons of things you can do. I would not suggest bypassing stages though.
#5
^Thanks, and thanks for that lesson on gain. By decreasing the gain, what I really meant was decreasing the distortion. Like i said, I probably won't use this with the sustain knob past 1 oclock. I'd like it to be so that with the knob fully counterclockwise its almost no distortion, and with the knob fully clockwise it sounds like it normally would at 12 o'clock.

edit: Kurt, I just went to your website, it looks cool. I saw your "The List" page, and saw that you have modded your Big Muff. What mods did you do?
Schecter Gryphon; Ibanez AEG20E
Peavey Rage 158 ; TRAYNOR YCS50
EHX Big Muff Pi; Dunlop CryBaby GCB-95 (modded); MXR M-108 10-band; DigiTech JamMan Looper
Last edited by BD 425 at Jan 10, 2009,
#6
^Thanks!

I added a standard 2.1mm DC jack and power filtering. I also add a little switch to get rid of the mid cut and make it flat response.

Overall not much changes, I like the BMP stock. It's classic.

I would increase the feedback stabilzing resistors on the first three stages. (these are the 100R resistors on the emmiter to ground.)
#7
^I was thinking about adding a mid knob, just for more versatility.
Is is possible that when I have the Sustain knob up past 1oclock it's causing my Spider to clip or something like that? once I turn it past 1oclock it makes this weird crackly sound when I hit a note, more on the higher registers of the fretboard.

I might be getting a tube amp in the next few months, so I don't wanna do too many mods to this thing, cause I feel like my amp just isn't doing it justice.
Schecter Gryphon; Ibanez AEG20E
Peavey Rage 158 ; TRAYNOR YCS50
EHX Big Muff Pi; Dunlop CryBaby GCB-95 (modded); MXR M-108 10-band; DigiTech JamMan Looper
#8
The Spider is going to sound like shi t no matter what. You need to get a better amp.

The clipping is coming from the pedal Clipping is what causes fuzz/distortion.

Crackling usually means DC is leaking into your signal, probably a bad coupling cap.