I was playing on my friends seymour duncan twin tube classic pedal yesterday, and suddenly the lead and rhythm channels got really quiet, and had no gain on them, even though the gain was turned up a pretty good amount on both. The bypass still sounds perfectly fine though, exactly like it did before. (its true bypass if that makes a difference). I'm new to tube gear, is a tube blown or broken? I opened it up and the tubes looked fairly normal, but I didn't get to see what they looked like before this happened. Also if the tubes are broken, where could I get new ones of the same type? I'm 99% sure the warranty no longer applies, he's had this thing for a while.

You can get 12ax7 anywhere. Just google em.
Tom Anderson Hollow Classic
72 thin line tele

Barber trifecta fuzz
Mi audio Crunch Box
Clyde Wah
Barber Burn Unit
Ocean efx Texas deuce
Boomerang chorus delay
Barber ltd

1971 Pro reverb
Fender acoustasonic
Fender super champ xd
Is it battery or adapter powerd? Check if the battery is empty first.
Since you've given no location, I can't help you on where to find tubes. Also, there is never waranty on tubes. They break always break down at some point, that's just their nature. you can't get a refund if your goldfish dies, do you?
thanks guys. I knew I forgot something. It's adapter powered, and I didn't change outlets at any point. I live near detroit. I was fairly sure the warranty wouldn't apply also hehe...

and this is the info about the tubes from guitar center. I know obviously the crap about how special they are is just a marketing thing.

Uses two premium, military-spec, subminiature, USA-made Philips-Sylvania 6021 dual-triode tubes
If you can order online do to dougstubes.com.

12ax7s are fairly cheap and easy to install as well.

Oh basilbrush, if the goldfish dies within a week, you can get a replacement
Agile AL3000
Douglas WRL90
J&D Strat
Squier Tele
Sammick TR2
Douglas Draco
Peavey JSX
Bugera V5