well, they are a bit different, the SD1 is very much an assymetrical clipped tubescreamer with less of a lower-midhump built in... the OD1 is the basis for all TS/SD1 type pedals with diodes clipping the feedback loop and not the whole signal (they call this 'soft clipping), but its very different, more primitive, and other than a huge bass rolloff built in, its much flatter (there's also 2 versions, the original uses a discontinued opamp and that one sounds noticeably different, some say it sounds better)
the MXR GTOD dude mentioned is very much a flatter TS9/TS808, a lot like the 90s green rhino whereas the Custom Badass I favor is more like an SD1 with OD1 mids that lets you reboost the bass and also gives you a switch to give it the tubescreamer low-midhump... then there's the green rhino mk2, also technically a Dunlop, has fully variable midhump or cut along with the 100hz bas boost, but otherwise has the TS symmetrical clipping, basically a super tweakable GTOD.... then there's the Zach Wylde which I believe is very much the same pedal as the GTOD, but with more mid push getting closer to a stock TS9 like the dude used to use out front of his 800s before the Dunlop deal.
these are all very similar designs on paper from the OD1, the genesis of this style of circuit, through to all the hot rods like the way huge or the crazy configurable Pallisades by EQD... a change of diodes, opamps, input cap and tone pot value revoice the whole effect pretty drastically (until the rest of your band comes in and swallows those nuances LOL) which is probably why this style of pedal is so popular with modders and small builders... and they sound pretty good, very much a classic tone now in and of themselves
in diode clipping distortions, there's this type, the 'soft clip', then there's 'hard clip' with diodes clipping the whole signal to ground right before the output or sandwich between 2 opamp stages which would be like a DS1, rat, DOD 250, distortion+ etc and then there's dynamic clipping, which ahs diodes to a transistor stage's bias potential within the opamp/IC and that's the discontinued Voodoo Lab OD, Fulltone OCD, the joyo OCD clone etc.... tis a cool idea and it would be nice to see it applied to other clever pedals like the Klon design that only diode clips the high frequencies and then relies on some antural transistor overload giving the klon its marshall-esque rresponse.... if the diode section on the klo were more dynamic I think more people would sue it for heavier distortion instead of just a boost or light OD.... I should make that pedal
anyway, even the lowly DS1 CAN sound quite good even though we al love to hate it... I am a known tone snob, but I am also a creative musician and I am not afraid to make a bad sound into a good through context, so I don't think anyone should discount any dirt box unless they try it in their rig and it just won't do what they want (and even then, it might be useful to you in another situation)
personally I am the enemy of huge pedalboards, so for live I just do "my sound' which is mostly amp based, but when I am recording anything goes.... I think I have the least stuff I've ever owned right now, but its still a lot... last time I made a record with a band the horde of gear was obscene and I think we tried everything even though a handful of amps and 1 old fuzzbox wound up stealing the spotlight for most of the album! but it wasn't my turing rig for that band, I barely used my road plexi or the 'barney' metalface and used a new reissue a lot more because it just worked.... and a lot of the time the overdrive is actually a boosted fender and not a marshall because THAT worked. On its own that fender dirt was not so special, you don't think blackface twin and power amp distortion, do you? but with the bass and drums it was great....
so what makes a great fusion sound? I don't know, what does the song want? what kind of tones do the other musicians bring to the party. I can't just blanket answer such a broad question. I think the real key ehre is that if you are playing professionally you should acquire new stuff but try to avoid selling stuff because it might surprise you later. I only reluctantly thin the heard now that I am not a pro.
