This has been covered way too many times, I guess I'll start putting together a rant that'll hopefully sit in the sticky section and kill these questions.
There shouldn't be any difference between the two, seeing as how they're the same bloody circuit. For that matter, the Boss SD-1 is very close (but has asymmetrical clipping, which I think makes it even better) and the $40 Ibanez TS7 (that people seem to bash because it's fun to pretend we haven't gotten ripped off on gear) is the exact same circuit.
Before anyone asks, the TS808 is literally two components away from the TS9. You could set up a switch to go between the TS808 and the TS9 in the same box.
Unless what I've been told about the Maxon and Ibanez pedals, and what I've gathered from all of my own (admittedly limited) observations of the two, happens to be completely wrong, they're the same circuit and any difference you hear between two is going to be a result of component fluctuation. Granted, this can be fucking huge - even great companies will have 5 to 10 percent tolerances in their components very frequently - but it's important to not buy into hype and think that you have a huge, life-changing decision in front of you. It's a couple of fucking shiny boxes. I've played Ibanez and Maxon fucking shiny boxes and there were a few times when two Ibanez boxes were farther apart than an Ibanez and a Maxon. On top of the design being the same on those two and a few other boxes Ibanez has done (like the TS7, which at half the price of the cheapest Maxon I've seen is unquestionably the best deal), I don't think it matters all that much because of the tons of gain you'll be shoving on top of the minute and inconsequential differences between them. If you're the kind of sick fuck that thinks that a chocolate cake can be ruined by using generic salt instead of the kosher stuff, then by all means waste ten steak dinners' worth on the pricey ones. Honestly, I'd say just to get the TS7 - it's the same circuit, and at the price it's at you could get two and just be really snobby about having a favorite when you have guests over ("No, no, no... don't use that one, use the *good* one - here...") for dinner.
As far as volume and tone questions, they're used to shape the tone and slam the amp in a different way - the circuit itself tends to leave a very mid-heavy sound and this helps beat the preamp into submission more effectively. If you've ever played pickups like the Dimarzio Super Distortion or any of the other super-middy high-gain pickups from way back when, you'll notice a different response compared to something trebly like a Strat. It tightens the sound. On top of that, you can use it to brighten or darken the sound, in a more complex and useable way than the tone knob on a guitar. They will, being clipping circuits, inherently add a little more distortion and compression, but you don't use the pedal for its distortion because that's why you've paid a grand and a half on a box with pissed-off fucking light bulbs in it.
The Tube Screamer circuit is itself very interesting - maybe reading about it will help make more sense of it. Contrary to what the goddamned salesmen love to say - "It's one of the original tube emulators, it sounds like an overdriven tube circuit..." - it doesn't sound like a bloody tube. It was designed to make tubes scream by hitting them harder. It cuts out a lot of bass and a bit of treble, tightening the sound and making the job of clipping it smoothly and controllably easier. As much as people seem to think bass-heavy monstrosities sound as pickups, through a lot of rigs that's like trying to get a girl off by going at her with an exhaust pipe - she's not likely to be able to handle that fucker well. You're going to lose detail and finesse, period, because the clipping circuit can only do so much - you're essentially putting a couple of diodes after a gain stage and making them lop everything that's too big to fit on the rollercoaster. Think of it like making sausage, or rolling pasta - you're shoving it through a machine that reshapes something mechanically by only letting so much through. Now imagine trying to shove a whole goddamned pig into a sausage maker - big, bloody mess that's just not going to work out too well as food. I'm sure you could take it to the ex and have a go, but if you're trying to have something manageable and edible you're going to have to trim some stuff off before you shove it into the machine. After filtering out the sound somewhat, the clipping stage is very simple, but with a little twist - normally a pair of diodes going in opposite directions are used to get diode distortion, but the Tube Screamer adds to this a very small filtering capacitor that gets rid of some crackle and fizzle, and because of the way it's placed the amount of filtering varies with the drive setting. This leaves a much more natural and listenable overdrive. It also makes it easier for the amp to distort it, because it's in a format the amp will handle better. This becomes even more important with down-tuned guitars - the standard low E that every amp is supposed to be used to has its fundamental around 82.4 Hz, but take that fucker down down to Carcass territory in B and the fundamental is at about 61 - we've gone down half an octave, which changes the way the amp will have to respond to things quite differently. Go back to the girl you're shoving an exhaust pipe into - repeat, but this time tell her she's getting a couple of fingers. Not fucking fun, is it? The amp is going to deal better with midrange, which is why the Tube Screamer comes into play.
Jeff
:Smokin:
