Noisy Pro Junior 4

[Cyberi4n]

Got a weird noise in my Pro Junior; before I start pulling tubes etc perhaps someone has experience of this?

Basically, volume on 4 (clean) there’s a bit of hiss and it sounds like there’s a reverb attached, so the note seems to decay in a very echoey sort of way (but quietly, it’s not a dominant sound at all).

I’d just added a CC delay to the chain, set low in the mix, and it sounded just like there was a problem with the pedal not switching off, as though it was still engaged, albeit quietly. So I ran guitar straight into amp and the sound was still there.

It’s a relatively new pro junior, with stock tubes other than a new JJ in V1 that I put in some weeks ago. The amp is running clean, with relatively few playing hours (<150) and for this I was running straight in, not using my pedalboard. Problem has only just manifested itself.

I’m guessing one of my tubes is microphonic, but before I start pulling tubes I was wondering if any of you have any experience of this and how you solved it. Appreciate it’s difficult without any sound files attached, but it really DOES sound just like there’s reverb or slapback delay on it, set low.

Preamp tube problem?
Power tube problem?
Or something else problem?

 

[corliss1]

One no-cost option would be to hook the amp up to another speaker, if you have another speaker available to test with. If not, swapping tubes is the easiest and cheapest thing to check. Anything other than that, and it likely needs to visit a tech.

 

[lammie200]

The Pro Jr. that I had was noisy. I changed the output transformer for a better Mercury Magnetics brand and the pre amp tubes to lower gain versions that fit the same as the stock ones. Helped a lot. Also take out the top middle screw on the back. It can short out the chassis.

 

[Cyberi4n]

Update: pulled all the tubes, one by one. The hiss has now virtually gone. The weird reverb type effect has virtually gone too. The decay on the note still sounds weird to my ears, but I’ll keep an eye on it as it may well just be me overthinking things… as usual

 

[corliss1]

Maybe you just had a dirty pin or socket, and pulling and reseating them polished it up just enough to resolve the issue. It does happen.