Hello friends and greetings from The Emerald Isle.
This is my first Mesa amp the Express 5:50 1x12. I bought it second hand and it is about 8 months old now. It sounds great but a little bit hissy compared to my Fender HRD. I decided to order a new set of tubes from Doug's Tubes after reading a lot of posts. I ordered
(1) Matched Pair SED 6L6
(1) Tung Sol 12ax7
(1) High Gain JJ JJ/Tesla ECC83S
(1) Penta 12ax7
(1) Shuguang 12ax7 9th gen.
(1) Sovtek LPS 12ax7
The new tubes made a great difference and cut a lot of the hiss. I played a gig last Saturday and the amp sounded great. This is the interesting part. About three days later I turned the amp on at home with no guitar plugged in and hit the footswitch and changed from clean to crunch channel and the next thing there was this terrible noise exactly like a siren winding up and it continued until it reached a certain pitch and stayed there. I switched over to the clean channel and no siren. I then hit the pedal and changed to Burn channel and siren noise again. I then changed back to clean and no siren. First thing I thought of was it must be something to do with the new tubes. I hadn't time to mess with it at that time so I turned the amp off and I sent Doug an email and told him what was happening. He said it could be a tube and told me to switch preamp tubes one at a time to try and find out what one was maybe bad. I switched the amp on later to do what Doug had said and tried changing channels first and no siren noise at all and it hasn't came back again.
I would appreciate it if someone could give me a clue to what this might have been please. The amp sounds great. Just a bit worried about using the amp this weekend in case this siren noise comes back again. Thanking you for your time.
This is my first Mesa amp the Express 5:50 1x12. I bought it second hand and it is about 8 months old now. It sounds great but a little bit hissy compared to my Fender HRD. I decided to order a new set of tubes from Doug's Tubes after reading a lot of posts. I ordered
(1) Matched Pair SED 6L6
(1) Tung Sol 12ax7
(1) High Gain JJ JJ/Tesla ECC83S
(1) Penta 12ax7
(1) Shuguang 12ax7 9th gen.
(1) Sovtek LPS 12ax7
The new tubes made a great difference and cut a lot of the hiss. I played a gig last Saturday and the amp sounded great. This is the interesting part. About three days later I turned the amp on at home with no guitar plugged in and hit the footswitch and changed from clean to crunch channel and the next thing there was this terrible noise exactly like a siren winding up and it continued until it reached a certain pitch and stayed there. I switched over to the clean channel and no siren. I then hit the pedal and changed to Burn channel and siren noise again. I then changed back to clean and no siren. First thing I thought of was it must be something to do with the new tubes. I hadn't time to mess with it at that time so I turned the amp off and I sent Doug an email and told him what was happening. He said it could be a tube and told me to switch preamp tubes one at a time to try and find out what one was maybe bad. I switched the amp on later to do what Doug had said and tried changing channels first and no siren noise at all and it hasn't came back again.
I would appreciate it if someone could give me a clue to what this might have been please. The amp sounds great. Just a bit worried about using the amp this weekend in case this siren noise comes back again. Thanking you for your time.
