Orange Amps Forum

what can i do about this, what can it be?

sounds like whatever 2 power tubes aren't being used in half power mode are bad. i'm assuming you're referencing the power scaling feature on the back of your amp? does it hiss and hum on full power only, or also when all four tubes on half power is selected?

if it is your tubes, no worries, this isn't anything major. it's pretty common, especially in the very beginning of tube life for tubes to go bad.
you need to buy a matched set of power tubes; in your case, el84s. these are fairly cheap and can be found at your local guitar store. i believe the TH30 is a cathode biased amp, so you don't need to worry about biasing your amp

it hisses when i put it at full power, even if tis 2 tubes or 4 tubes... with 2 tubes at 15 watts and 4 tubes at 30 watts

jpish0t wrote:it hisses when i put it at full power, even if tis 2 tubes or 4 tubes... with 2 tubes at 15 watts and 4 tubes at 30 watts

Not sure what to make of that. What did you expect it to do at full power?

interesting? they only operate well when it's 4 tubes at half power?

that's pretty wierd. where do you have your gain set? if it's too high, (and even if it's not), you're going to get a little hum out of any tube amp. same for hiss, if your gain is too high. other factors, like your house wiring and how close you're standing to the amp, and how hot of a signal you drive into the preamp have to do with it as well. although that doesn't quite explain why it doesn't work well when the tubes are at full power

this sounds a bit like the problem i had with my TH30. 2 tubes fine, 4 tubes, crackly/scratchy noise. i swapped to new tubes too but still the same.

i sent it off, they fixed it but didn't tell me what it was!

My first question, how loud is the hiss and hum you're describing. Some hiss and hum is normal.