ive heard of people putting both an od and a distortion pedal through their tube amp at the same time. what does this do and should the distortion be before the overdrive,or vice versa?
what does it do? : well, 9/10 times it muddies up your sound and makes it one big sloppy distortion fest.

what kind of amp do you have??
ok. yeah. you dont need both a distortion pedal and an OD pedal running at the same time. when you get the hotrod all youll need is a good OD pedal and youll be able to achieve all kinds of distortion sounds.

what kind of music will you be playing through it?
I know some people that go from guitar into OD then into Distortion pedal but only kick in the OD for a gain boost in solos. Pointless if you already use massive gain. Its only like putting an OD like a tube screamer in front of an amp to give it an extra kick, only thing is, a distortion pedal wont act in the same musical way that an amp would when its bein pushed.
No reason why you cant though. If you like it go for it.
well what pedal should i get to use as probably the main od on the amp? i play stuff from anberlin to gnr or maylene. so i need it pretty heavy
^ use the "edit button"

i just use a SD-1 to boost my JCM900. standard, simple, inexpensive. but it sounds pretty damn good.
SD-1 Keeley ??

Oh yeah, I still dont get why Steve Vai and Joe Satch use DS-1s ??
Tone is all ...... well probably 75%, in your fingers.
The rest depends on your wallet's thickness !!

Keep the faith, baby!!