Hi All

I recently bought an Orange Rocker 30, which is an all tube amp, second hand. It was fine but now its making noise. And I would really appreciate some help and advice on how to find whats making the noise.

It makes crackling sounds and a distorted buzzing type sound every now and then. The noises come at random and are intermittent. It is quiet when I'm not playing.

I love my rocker 30 but this noise is killing the good vibes really fast.

I have no after sale support here so I have to figure this out myself.

Any advice guys? Perhaps a good place to read about diagnostics?

The first thing to check is always the tubes. Get a set of new ones and see if that fixes it. It's a good idea to replace the preamp tubes one at a time, so you can tell if just one was bad and keep the rest for backups.

After that, clean out the inputs, especially the reverb pan inputs if it's got that (I don't think that amp does though?) and then after that you'll need to have a tech check it out. Hopefully it's just a bad tube. The fact that it only comes when you're playing makes me think it's just a tube, which is good since it's a lot easier to fix than an issue on the board.

I have found that the crackle and noise comes in especially loud when I play a Bb note. Why is that?

Also what tubes should I get?
The tubes might be microphonic, so they rattle most at the frequency of B flat.
I'd get a JJ 12AX7 for the spot farthest from the power tubes, 2 Sino (chinese) tubes for the other two spots, and a matched pair of El34s. You can go to kcanostubes.com or tubedepot.com for those.
For the matched pair of EL34's, which brand should I go for? I'm kinda new to this as you might have figured.

Thanks for the advice Roc
Please click the "edit" button instead of double posting.

Microphonic power amp tubes can sound something like what you described. I'm just suggesting a full retube because it's a good idea to have spare tubes around, and it's a good diagnostic technique. It would cost you the same amount to bring it to a tech, which you might have to do, but this is money well spent even if it's not a tube issue, and the most in-depth you're going to be able to get as far as troubleshooting by yourself.

JJs for the El34s, by the way.
I read that those JJ's are a bit fragile for use in a powerful combo. I'm looking for something that will be pretty bulletproof (as far as possible for tubes obviously). Is there any substance to this claim that JJ's are not suitable for combos? and are there any suggestions if so?