This is a Boss SD-1, modded by John Spina ,a.k.a., "StratDeluxer". John has been a member of a number of guitar forums, and has contributed tutorials to the Tokai Registry and Project Guitar. Among his specialties are "no load tone pots", and "hybrid magnet swapping" in pickups. He's also been modding his own Fender and Marshall amps for years, as well as his pedal mods.

Pedal mods have become more and more popular. The Boss pedals are good mod candidates, since they come in a tried and true, good package, with a decent bypass buffer circuit and a dependable footswitch. At about $40 new, both the SD-1 Super Overdrive and DS-1 Distortion units are great pedals. Modded, they are enhanced, and notched up a bit. The SD-1 is smooth, fat, and creamy, like a cross between a good overdrive and a Vox ToneBender, with long, silky sustain that loves legato lines. The modded DS-1 is a mini crunch machine - a Marshall stack in a box, especially good for crunchy chord work. Both mods help overcome some of the harsh tendencies of the stock pedals.

Enjoy!

here are some (editted) comments I sent to John after trying the pedals:

both pedals were fat and smooth. I tend to prefer the SD-1 for soloing, and the DS-1 on rhythm parts. I think your clips of the DS-1 had more chord work, so I don't know if that's how you feel as well.
I found I could get that long, silky, violin tone pretty easily with the SD-1. I would say that "Eric Johnson" tone, except for one thing: I can't play like Eric Johnson!!!!!!
Nah, it was really suited for long, legato playing ... that's probably the main reason I say I kinda lost track of time ... lot's of fun!!! :-)
I think of the stock pedal as kind of a Tubescreamer with a flatter response, meaning no big mid bump or bottom loss. The modded pedal to me gets into almost fuzz territory, except smooth, not raspy. Kind of like the good features of a Tubescreamer crossed with a Vox Tonebender - and that, my friend, is a good thing! That was probably at first, without adjusting the knobs much from how they got here. Later, the second time I played, I adjusted things for a flatter response, so the level was closer to my "pedal off" level, which is how I set most of my OD's... I want some coloration, but fairly subtle.

Set flatter, the SD-1 lent itself more to blues playing. Still fat and smooth, but probably a little more friendly in larger doses. ;-)

Overall, a heck of a lot of fun!! I give it 9 out of 10 flaming chili peppers
(I'd give you 10, but I want you to keep striving!)