Rocker 15 12AT7 Tube issue

[AlRose]

Had this little combo for about 3 months. Great tones from a small package. However, I've cooked 2 of the effects loop tube, a 12AT7. Could be my board (unregulated PS), could be the tubes. I looked on the circuit board in the amp and nothing is burnt. Has anyone else had this issue?

Al

[Ronnie Robinson]

If 2 tubes have gone in the same position in a 3 month period it could be an issue with the amp (unless you've been really unlucky with tubes!) I'd keep an eye on it and consider returning it to the dealer for Orange to check it out.

[langmurf]

Asking the question which has, one assumes, a painfully obvious answer... one knows the 12AT7 is shot because the effects loop ceases to function? Is there any indication that the tube is failing or is it just 'lights out,' loop stops working?

I'm no pro... the R15 is the first amp I've ever used the loop on. Have an Orange Two Stroke hooked up now. I guess if I stomp on the Two Stroke and nothing happens, I'll need to crack open the amp and look at the 12AT7.

[AlRose]

@langmurf - actually, the amp stops working. I had 3 pedals in the loop and nothing. Pulled everything out and nothing. Changed cables and nothing. Well dang. Removed the chassis and found the tube to be all white...ie toast. The first tube a few days earlier went microphonic. I opened up the amp and nothing is blown. The tubes were JAN Phillips 12AT7WC, a robust tube. Put the stock Ruby 12AT7 back in and everything works again.

Now, in thinking about it, I realized I had, on 4 or 5 occasions over the last few weeks, forgotten to turn on my pedalboard first before firing up the amp. The pedalboard PS is an unregulated 1-spot. So might be my fault. I've ordered a Strymon regulated PS for the pedalboard, and will now unplug the pedalboard after I'm done, and plug it back in before I fire up the amp and see if the Ruby survives. I've got a bunch of additional NOS 12AT7 tubes, but don't want to toast them as well until I figure this out.

BTW - the amp sounds awesome with GE EL84s, RCA 12AX7A, and the Jan Phillips in the loop spot. Much better to my ears than the stock JJ's and Ruby....

Al

[Jondog]

Your pedal power supply should not have anything to do with the effects loop. Could just be a bad tube. If the tube turned white, it’s lost it’s vacuum, which could mean it’s cracked somewhere.

[Sootio]

When mine went, the amp started making some strange and unpleasant noises. I took it to an official Orange repair shop and the verdict was the 12at7. Replaced the tube with a JJ and I've never had another problem and it's been at 3 or 4 years.

[Les Paul Lover]

Your pedal power supply should not have anything to do with the effects loop. Could just be a bad tube. If the tube turned white, it’s lost it’s vacuum, which could mean it’s cracked somewhere.

Yes, that valve had it.
Very unlikely the 1spot had anything to do with it.

I've been using a 1spot and another cheapo mooer unregulated power supply without any issues whatsoever on my RV50 (fx loop), R30 and AD15 (No fx loop), and I've never paid attention to what gets plugged when.

One thing with NOS valves, is that you're rarely sure they actually NOS. They very often have been pulled out of radio or older Organs, guitars amps or TV.

And as always.... valves can go bad anytime.