Issues w/ MK IV B. Please Advise.

[mandoismetal]

Hello all!

In a previous post, I had mentioned that I had replaced a pot in the amp and forgot to plugin the speaker afterwards. I tried playing a few chords while messing with all channels and volumes before I realized my stupid mistake. I've been a little paranoid about having caused some damage to the amp by doing that.

Here's the scoop. Whenever I play on the lead channel, I can hear this sort of build up static/interference (not hum) that varies in loudness/volume.
I noticed that the noise worsens as the gain/volume increases in this channel. AFAIK, the noise can NOT be hear in R1 and R2 channels even at max gain, volume (I even tried a clean 20 db boost on top of that).

I'm inclined to say that it could be a preamp tube that's going bad. However, I can't rule out having damaged the amp by playing through it without a speaker load attached.

Any feedback will be appreciated!

Thanks for your time,

Mando

 

[stokes]

It could be just a dirty/loose tube socket.With the amp on and set in the mode that you hear the static the most,try wiggling the preamp tubes one at a time in the socket.Chances are you may hear the noise from various tubes.Have the sockets cleaned and re-tensioned.It is unlikely that you did any damage to the OT,it takes playing without a load for quite a while before the OT will fry,they are tough,and the output jack is "shorted" with nothing plugged into it to prevent it from frying immediately.The fact that it gets worse when you turn up the gain is indication the noise is coming from a point in front of that knob,not the out put.

 

[mandoismetal]

Thanks stokes.

All the sockets have the right tension. I reseated all the tubes and the problem was still there.

I replaced it with a new one and the issue is gone. For good I hope.

Thanks again!

Mando