Revisiting and restoring my old DIY Big Muff pedal.

[DrNomis_44]

Hey everyone,

After watching two videos on youtube by an American guy called The Guitologist, I got inspired to get my old DIY Big Muff pedal out of retirement and do some restoration work on it tonight to get it fully working again, it doesn't really need much to get it working, just two sockets, a 3PDT footswitch, a 9V battery clip and a 3mm Blue Led, I'm pretty sure the circuit board still works well.

Here's a couple of pics of the pedal as-is:


The front:

43401


And the insides:

43402


This restoration job should be fun.

[DrNomis_44]

Update:

Last night, I finished working on my old DIY Big Muff pedal and as far as I can tell by tracing through the circuit board with a signal from my DIY Function Generator and my DSE Q-1804 Dual Trace Oscilloscope, the pedal seems to be working as it should, I had to swap-out quite a few of the capacitors on the circuit board because there was just too much bass in the tone I was getting while testing the pedal with my Boss Katana amp, no wonder it sounded so bassy, most of the caps were 3.3uF in value when they should have been 0.1uF and 1uF ones, anyway, I changed out the 3.3uF caps for the proper values and now the pedal sounds much better, there's non of the bass muddiness I was getting before.

[Simon Barden]

Why the wrong value caps?

[DrNomis_44]

Why the wrong value caps?


Not sure, it could be that the original circuit I used to build it had those values marked on it, I do seem to remember that I decided to use the original Triangle Big Muff circuit, the one Electroharmonix used for the original silver ones, over the years Electroharmonix tweaked the Big Muff circuit, I'm assuming that was to correct problems in the tone.

[Simon Barden]

I’m not sure about ‘problems’, as those early Big Muffs are highly sought-after. The very first Big Muff Pi units are generally considered to be the best sounding Muffs. There were small variations after that to work with the components readily available as they were buying in bulk and looking for lowest prices, so a 500pF cap may be replaced by a 560pF cap. I believe that they produced updated diagrams for each component variation, so that the board assemblers still knew where to put all the components. But the basic circuit remained the same, and the changes weren’t official variants (though I think 18 different diagrams exist for the first iteration of the Big Muff.

[DrNomis_44]

Update:


Since the original circuit-board in my Big Muff pedal is getting a bit crusty (same like me...hahahaha.....*snort*...*snort*), some of the copper tracks are starting to lift as well, I've decided that this fortnight I'm going to make a new circuit board using a piece of pad-per-hole board that I happen to have in my stash of bits and pieces, I did a quick Google search for a suitable layout and found a good one for the Ram's Head Big Muff circuit, so, looks like I just got myself a new pedal project to work on this fortnight, I'm going to be paying a visit to my local Jaycar Electronics shop tomorrow to buy some parts for another pedal build project I'll be working on this fortnight, so I'll have plenty to keep me busy....whether that's a good thing or not is wide-open to debate, but I digress....if anything, it'll be fun anyway.


Here's a link to the layout I will be using for the re-build:

http://effectslayouts.blogspot.com/2014/12/electro-harmonix-rams-head-big-muff.html

Here's a link to a webpage detailing all the different versions of the Big Muff circuit:

http://www.bigmuffpage.com/Big_Muff_Pi_versions_schematics_part1.html



Here's a pic of the new pad-per-hole circuit board I'm making for my Big Muff pedal, I took this pic after cutting the board to size and marking the component positions using a black sharpie pen, I'm going to be using some tinned copper wire to form all the tracks joining the components together after they are all soldered in place, one day i might do a mini-tutorial about how to build circuit boards for pedals, using pad-per-hole boards, anyway, here's what I've managed to get done so far:

43525


For those wanting to do the same, you need to cut the pad-per-hole board so that the board is at least 18 by 23 holes, you can make the board wider so you have plenty of room for making mounting-holes for circuit6-board standoffs, which I've done here.