Preamps

What's the difference between a preamp and an overdrive or distortion pedal? Does anyone have any experience with a good tube preamp I could put with my Fender hot rod deluxe to get a classic rock sound?

I would like to try this one but my local shop doesn't have it.

http://www.guitarcenter.com/Seymour-Duncan-SFX-03-Twin-Tube-Classic-Preamp-Pedal-103646469-i1124941.gc

What you mean is probably a footswitch.
A footswitch only switches the channel on your amp. Meaning you are still only using your amp, just it's different channels which you can put to different setting, not wasting any of your tone.
Since most amps don't have many channels (2) it's clean and distortion or overdrive channel, so it's often called that.

A pedal preamps your real amp to give it different sounds.
Personaly I only use footswitches, no pedals, if I wanted other sounds I would have bought a different amp.

No I mean a preamp pedal. I need advice on an all tube preamp. I think they are about the same as an overdrive or distortion pedal but I'm not sure.

I unfortunately can't help you out Les Paul, sorry.

But from the comments I've seen from GRX40, I would say ask him, because he seems to know a fair amount on this kind of stuff.

Actually I'm not too knowledgeable about preamps. I've looked around to see what they are, and most seem to be distortions and/or eq pedals.

But I think Lance mentioned preamp pedals in a post recently, maybe ask him?

there is a small variety of preamp pedals,from bluesy overdrive to
balls out overdrive+distortion combined. they make the perfect
companion to clean amps or those w/o alot of overdrive/distortion.
the difference between the masses of analog pedals and tube
preamp pedals is an all tube signal path. natural tube distortion
and overdrive is where the tone is at.

i actually just got back from my buddies shop tying out different
tube preamp pedals in combination with my 5w blackheart. i will
promise you there isn't an analog pedal on the market that can come
close to a twin tube preamp's tone. i played them yesterday,but i
needed to hear what they would sound like on my amp,so i brought it
with me this time.and no BS some of the customers that came in the
store thought i had my amp plugged into the randall 1/2 stack next to
it.(i was only plugged into the 4x12 cab below a randall RM100KH head)
i could make my 5W amp sound like a marhsall jvm or mesa with the
volume at 1.

this is the damage control demonizer(my fav)keep in mind any tube preamp
pedal needs to be played through a clean channel or the tone goes to
hell.the better the clean the better the tone. these videos were
recorded w/o an amp from the direct out on the pedal.
this preamp pedal is the monster of the series at $299 but it can
still be tamed back by merely adjusting the drive as you'll hear in
the vids. the tone you hear in these videos is what you will hear from
your amp if it has a pretty good clean channel.

this is a rather long review broken into two parts.
the second video gets into the heavier stuff.