OR15 - Recently started loud hissing

[Kieron]

Hi!

Im going a bit nuts here...

Recently my OR15 (which I love) has started having a jet engine esque hiss whenever I havw it turned on and with something plugged in. The only way i can now use my amp live is with a noise gate in the effects look or by riding the guitar volume like crazy.

You can hear what I mean here: https://youtu.be/CJFNSOZ-WtI

Scenario is that a guitar is plugged in, volume on guitar turned right down, no pedals (first to amp).

It happens whatever guitar is plugged in. I am going into a PPC112.

I have taken this to 2 repair guys who have both said they couldnt find anything wrong with the amp. This wasnt happening before and its driving me nuts! Annoyingly I am just a few months out of warranty.

Any advice anyone has on what this could be or where I should at least investigate further?

Thanks,

Kiero

[Jondog]

Could be a preamp tube going bad. Especially if it quiets down when you have the noise gate in the effects loop, shows nothing after the effects loop is making the noise which would be the phase inverter and power amp.

[LD50]

The whooshing jet sound (or wind blowing noises) does sound like a failing preamp tube.