Orange OR15 Amp Issue

joelorigo

Well-known member
I have an OR15 that until a few weeks ago sat unused for a while. A few weeks ago I went to use it and it powered up but there was no sound. I replaced the fuse on the back panel and it worked. I probably played it for 20-30 minutes. Last night after about 20 minutes it made a crackling sound and went silent. Searching this issue, several posts say the power tubes is most likely the problem. Do any amp experts concur? I have more fuses but I would have to order more tubes.
 
I am far from an amp expert, but I've had a few EL84 amps* in the past (AC15, AC30, Spitfire) and whenever a power tube was failing that's pretty much what I'd have happen - blown fuse, no sound, replace fuse, briefly works, repeat...

Can't offer a ton of input beyond that, but if nothing else...can always snag some new tubes off of Amazon to test, I guess?

*I have no idea if that's anything remotely unique to EL84 circuits, it may very well occur with any failing power tube, that's just my only experience lol
 
I just tried it again to see if letting it rest magically fixed it. There was sound but it was low volume and sputtery. I opened it up and the power tubes were loose, one was visibly leaning. I pushed them in and it was working seemingly normal. Then I shut down to add a pedal and now there is now sound again.

(I should also mention that I am using pedals through the fx loop but I first tried it with them unplugged. And took them out to try plugged in directly when it stopped working. Don't know if using the fx loop is a factor.)
 
Sometimes FX loops rely on shorting jacks to pass signal when nothing is in the loop. A friend of mine had a similar problem with a (I think) Peavey 5150. It was just that some dirt or corrosion had stopped the shorting part of the jack making decent contact - maybe the springiness of the contact had worn. Cleaning the jacks fixed the problem. That might be worth looking at.
 
Actually my first guess was going to be the tube rectifier but I checked the schematic I could find online and it doesn't have a tube rectifier. But as @jimilee says definitely check your power tubes. Kind of a no-brainer really now that I brain it!
 
I let it sit overnight and tried again yesterday with nothing in the fx loop. It was working and I played it for about 20 min. So the fuse isn't blown, right? Because twice now I have gotten sound out of of it after sitting for a while.

I kept it on but put it in standby for about 15 minutes. Then I flipped it back on and there was a little crackle and no sound again. So 3 times now it has worked for a bit then stopped. Does this point more to the output tubes or possibly something else?
 
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