Looking, as most of us do, for a cheap way of getting something that sounds expensive I came across the Monte Allums pedal mod site, and that in turn led me to the Boss SD-1 and some quality time with a soldering iron. The SD-1 is a cheap-as-chips overdrive pedal, built in the usual Boss tank-like manner, employing a very similar circuit to the (rather more expensive) TS9 tubesreamer. Mr Allums offers a number of mod kits for this pedal, all at really rather attractive prices. Do these mods deliver and, if so, just *what* do they deliver?
Monte's mods basically replace a number of key components with ones of better quality and sometimes of different values to those in the stock unit. A couple of mods also provide additional functionality with the addition of a microswitch (or two) - one such mod allows you to select between the stock unit's normal gain and a x2 option, another lets you switch between Boss's patented asymetric clipping and the symetric clipping employed by the Tubesreamer and others.
The kits arrive (very quickly, I might add) in jiffy bags containing instructions and a plastic bag of parts, decent solder and some de-soldering braid. Personally, I'd suggest using a solder-sucker rather than the braid, but its inclusion is a nice touch. You'll also get the instructions emailed to you. The instructions really are as easy to follow as Mr Allums claims and if you've a modicum of common sense, some patience and some basic skill in handling a soldering iron (of the electronics project variety) then you'll have no trouble at all using these kits. I really enjoyed doing them, I have to say.
So do they cut the mustard? IMHO, yes they do, and very clearly so. Monte recommends listening to each individual stage in the overall mod as you've made it (a) so you know where you've screwed up if you're unlucky enough to - easy to correct with this approach and (b) so you know what each specific mod does to the sound. My first effort was the "standard" SD-1 mod, and very impressive it was too. The clarity and transparency of the modded box is quite remarkable, as a clean boost it's truly astonishing and my bass-playing mate Al has grabbed the thing and it's now a regular part of his rig.
For my second go I went for the SD-808 mod, intending to use the two-microswitch approach. In the end I decided against the switches and went with asymetric clipping and the x2 hard-set as, frankly, this is the way I like the thing and I didn't see any benefit in additional complexity. YMMV, but the fact there's a choice is what makes these mods cool. The thing sounds fantastic in the right setting and I'll certainly be keeping it for the long haul, though whether it retains its current place on my working board depends what else comes along, the search for that elusive tone goes on.
Update: well there's a lesson here, I guess. It's now April 2011 and the Allums SD-1 is still my go-to overdrive unit and I don't think I'll be looking for anything to replace it. I've got used to it now and learned how to get the sounds I want out of it and I'm constantly amazed at just how good those sounds are. The modded device is wonderfully transparent and it enhances rather than compresses your playing's dynamics. If you're a classic rock/blues player then you probably can't go wrong with one of these - and at the price you'll pay it's an absolute steal.