2010 - Boss SD-1

This one came to me nice n' cheap. I bought it at a 2nd hand dealer in the city. $65 and practically brand new.
What do you do with cheap pedals? Mod them of course!

I'd read that this is basically a tube screamer with some parts changes.

Stock this pedal is pretty decent sounding, a moderate overdrive on full and a nice clean boost on minimum.
Unfortunately the filter caps on the input remove a lot of bottom end. So rather than add some punch, it cuts some of the guts out of it.

The first thing I did was to do the SD808 mod and turn it into a tube screamer.
Basically it's just changing one cap, removing another as well as a diode in the clipping stage.
What this does is make the clipping asymmetrical and alter the tone control.
To my ears and playing style, it wasn't much of an improvement. It still lacked the bottom end.

The next mod I did was the bass mod.
This is done by simply bridging two components, a capacitor and a resistor.
It was three weeks before I got around to testing it out, but when I did, the pedal was a whole new beast.
The gain still isn't much really, but that's OK I like it like that. The bottom end is nice and big, though a little muddy as there's a slight octave effect on some notes. But for the tone I'm after, this is almost perfect.

Placed in the FX loop of the Delta Blues, the pedal is responsive to dynamics and has the added bonus of acting as a master volume, though the extra gain from the preamp means that the pedal never completely cleans up.

I may end up doing some further mods to the clipping section and maybe change out the opamp for something else. But for now I'm pretty happy with this cheap pedal that cost about $1 and 15 minutes of my time to get close to what I want out of an overdrive.

Not too smooth, and just a little raspy.

2005 - Digitech Bad Monkey

In some circles this pedal is over hyped, in others it's not appreciated.
People seem to think it's just another tube screamer clone. And it is, even though it has adjustable bass and treble, rather than just a tone control.

They're cheap, which is a bonus, they sound good out of the box. Also good, since the components are surface mount and not easily modified. There are some "secret" bass mods out there, but if you're handy with a soldering iron and can do simple R/C calculations, you'll be able to do the mod for yourself.

I have two, mine are stock.
One was made in USA and the other in China.
There are no sonic differences to my ear, but there are some visual differences.
Namely the colour of the capacitors and from memory, the PCB's might be a different colour too (it's been a few years since I opened them up).

The sound of them is a mild overdrive to a very moderate distortion. Two in series is pretty good for a metal distortion tone. The distortion never cleans up completely, so they're not any good as a clean boost.
It could probably be changed, but the traces and parts on the board are tiny and I doubt worth the effort.

Even though this is an overdrive pedal, that's not really what I use it for.
It turns out that Digitech have incorporated into their pedals, a very nice DI, complete with the correct EQ to record the guitar clean or distorted through the "mixer" output. It balances the tone and simulates the reactive load of a speaker. I use it all the time when noodling with my headphones on or recording guitars when I can't mic them up (which is most of the time). Actually I like using the Bad Monkey in bypass mode to act as a buffer and signal splitter, so that I can record the unaltered guitar tone through the desk as well as recording an amp. That way I can change my tone/fx later and if I want to re-amp the signal for re-recording "live" effects.

You should be able to pick up a bad monkey for about $50AU.
While there's nothing ground breaking going on, they offer some very handy tools for the recording guitarist.
I've even used them live when there weren't enough Mic's available for the whole band!