Hi all,
I have a Mark IV rev B where one of the outer tubes red plates. After swapping tubes around and eventually replacing all of them with a fresh set it always happens in the same socket, so it seems there is something wrong with the amp rather than the particular tube. This happens as low as 1.5-2 on the lead channel master and the master volume when running in class A mode (a bit louder than apartment volume but not loud enough to annoy the neighbors) and roughly at 3.5-4 on either when running in simul-class mode (roughly rehearsal level volume). The problem manifests in either mode fairly quickly after turning the amp up and playing for 5-10 minutes.
The local tech I took the amp to (who is endorsed by Mesa) has made some interesting claims that I would like to run by the forum:
1. Master volume on anything higher than 2 is too high to safely operate this amp in class A mode. Anything higher than 4 is unsafe for operating in either mode.
2. Using humbuckers is prone to throwing the amp out of control because they are so high output.
3. The amp is absolutely fine and I should just play it at a lower volume.
I am not an electric engineer, but I am an engineer nevertheless and can't quite see the sense in these statements. In any case, they do not corroborate my previous experience with other Mesa amps or other amps in general.
Thanks in advance for your two cents!
I have a Mark IV rev B where one of the outer tubes red plates. After swapping tubes around and eventually replacing all of them with a fresh set it always happens in the same socket, so it seems there is something wrong with the amp rather than the particular tube. This happens as low as 1.5-2 on the lead channel master and the master volume when running in class A mode (a bit louder than apartment volume but not loud enough to annoy the neighbors) and roughly at 3.5-4 on either when running in simul-class mode (roughly rehearsal level volume). The problem manifests in either mode fairly quickly after turning the amp up and playing for 5-10 minutes.
The local tech I took the amp to (who is endorsed by Mesa) has made some interesting claims that I would like to run by the forum:
1. Master volume on anything higher than 2 is too high to safely operate this amp in class A mode. Anything higher than 4 is unsafe for operating in either mode.
2. Using humbuckers is prone to throwing the amp out of control because they are so high output.
3. The amp is absolutely fine and I should just play it at a lower volume.
I am not an electric engineer, but I am an engineer nevertheless and can't quite see the sense in these statements. In any case, they do not corroborate my previous experience with other Mesa amps or other amps in general.
Thanks in advance for your two cents!