Big Muff 1977 Opamp Stripboard layout VERIFIED

[Gila_Crisis]

so this is the finaly and working/verified layout for the opamp big muff.
enjoy it! cheers

note: on the little big muff pi (the old one with fixed maxed out gain, 2 pos. tone switch and volume pot) those 3 values differ:
C1: 68nF
R3: 68k
C8: 1uF

[paperhouse]

awesome, thanks! will this fit in an MXR sized case or is that asking too much?

i must say that the tone bypass switch is a great thing to have on my vintage opamp muff. it would be a worthwhile addition, IMO.

[Gila_Crisis]

yep it fits in a MXR sized box really well!!!

for the tone bypass there's a schem here: http://analogguru.100free.com/193/schematics/EH_BigMuffPi_OP-78.gif
it's preatty a simple mod to apply to the layout as well

[paperhouse]

awesome, i think i'm going to have to make this my second build (after i get around to building a red llama clone). did you put the opamps in a socket? i think it would be interesting to try out some different chips.

how do you like the sound? i have owned ~10 different muffs over the years and the op amp and skreddy mayo are the only ones that i kept. the op amp sounds really good at lower sustain settings - it gets a nice crunch. over half way on the sustain dial it gets really thick and sludgy!

[Gila_Crisis]

i always socket opamps and transistors, you'll never know!

i tried it shortly and it's seamed to sound great. btw i must put him yet into a boxes, after that a can play witzh it better.

[Gila_Crisis]

this is with the tone bypass switch:

[paperhouse]

thank you so much! i'm thinking this will be my second build, after i build a red llama.

be sure to post pics of the final product.

[paperhouse]

where did you order those caps from? small bear doesn't stock most of them, unless i'm doing my conversions incorrectly. 150nF = 150000 pF = 0.00015 mF, right? small bear only seems to list mF and pF.

[Barcode80]

150 nF = .15 uF

[rackham]

Just want to say a big THANKS! to Gila for his hard work on this one.

I finished my build about 1/2 an hour ago and it sounds ace

Huge variety of timbres available and sounds a lot more 'grown-up' than the fuzz face type pedals I've done so far.

I've put 2 guitars through it - a Parker P38 which sounded warm and nicely overdriven on the humbucker, with the single coils it sounds like it'd cut through a mix like a light saber.

The other guitar is a Westone Thunder. It's got 2 humbuckers and sounds like it has valves in it! Although probably not the most iconic guitar I love it. The Big Muff sounds huge and really compliments the guitar, the tone control is really effective and can take you from bass-heavy rhythm stuff to angular lead sounds.

It isn't as 'heavy' as I was expecting but in retrospect that's no bad thing, I've got an MT2 for heavy.

In short, build this.

[Gila_Crisis]

thank you rackham!

enjoy your new baby then 

[nokaster]

OK, so i built this one.

i've got some oscilation, so i think i'll replace R13 8k2 with a 33k
i'm gonna try the 8K2 in the tone stack, replacing R16 5k6, to see what the effect will be. (i found 2 opamp versions and version 2 has 8K2 for R16)

my main problem is that my big muff isn't fuzzy enough now. it's more a distortion than a fuzz. and i want it fuzzy!
maybe the opamp version isn't the best choice for that, but there should be one or more components to change to make it fuzzier?
can anyone help me with that?

i've used these opamp:
LF351
LF353
because i like them in other circuits and those are the ones i have here.
maybe they are the reason for the lack of fuzz?

any modding help appreciated!!!

PS: the distortion is very good, but not what i'm after...