i have a pitbull ul100 and i am wondering if anyone knows if this amp is self biased or not. if anyone owns a pitbull or has knowledge of this amp please help me out.

generally, preamp tubes are all self biased

output tubes in a Class A/B (like I believe this amp is) need to be biased to match the tubes.

Class A amps don't necessarily need biasing, but you need to still confirm that the output tubes all actually match each other. (Something a lot of techs just overlook and trust the specs on the tube boxes)

Mesa Dual Rectifier's Output section is known to be self-biased simply because the amp runs too cold to matter.

Other than those scenarios, I don't really know of other self-biasing amps.

Without really knowing much about the Pitbull, I can almost guarantee that it's not self-biased.

i replaced all of my power tubes the preamp tubes are still in idk if that makes a difference. i read on a forum that the pitbull45 1x10 combo is self biased in a class a, but when switched to class a/b you need to bias it, i cant find any info if that is the same with the ul100.
thanks for your help though man i appreciate it!

Get that shit biased. VHTs (for the most part) aren't self biasing.

i prob will just to be safe i dont want the thing to shit the bed while im on the road. hey blue i train your buddy over at sityodtong muay thai academy he was wearing a dysentery shirt and i asked him if he was a fan and he said he was your friend.

always a great idea to have a tech go through your head before hitting the road. that said, if you don't have time, just buy the exact same tubes that are in there already and you should be fine (assuming it's biased properly now).

NOOOOOOO

just because tubes are the same type and brand do NOT mean that they match the previous set you had in before.

well i had kt88's in before and now i put in 6550's but i read that they are interchangeable without a bias i dont know how true this is considering i cannot find any solid info on this amp not even on the vht website. i am going to bring it in just to be safe, it sounds fine now ,very powerful but i have never changed tubes so idk what would give a hint that something is wrong.