Bartimaeus
New member
I talked to Mesa a while back and they said some hissss is "normal" for this amp. But a buddy loves mine so much, he bought one -- and his is totally quiet. Barely audible hissss...
Comparatively my hisss is very loud. If I held my phone to the amp, you couldn't miss it.
The hisss is stable (doesn't increase or decrease across channels or volume/gain settings.) It was instantly there in both 5 and 50W modes.
Following Mesa's instructions, I swapped preamp tubes one at a time, alas, same results. If I tap the preamp tubes with fingernail? ... the only one that makes any noise (and just barely) is V4.
Then I swapped the whole preamp (5 - 12AX7's) with a set from a fellow on Reverb.com (swears they're fine.) I still have the hiss. And this: The new tubes added a little 60hz hum.
And again, if I tap the preamp tubes the only one that makes noise (and just barely) is V4. This happens with either tube in there (new or the old.)
The only difference I really notice (ignoring the 60hz hum) is that with the new tubes in the pre-amp - swapping to 50W mode, the hisss and hum take a while (more than 30 sec?) to "build in" and then seem much lower in volume.
Totally weird?
Or do I need new 6L6's?
Thanks in advance for the benefit of your wisdom,
Comparatively my hisss is very loud. If I held my phone to the amp, you couldn't miss it.
The hisss is stable (doesn't increase or decrease across channels or volume/gain settings.) It was instantly there in both 5 and 50W modes.
Following Mesa's instructions, I swapped preamp tubes one at a time, alas, same results. If I tap the preamp tubes with fingernail? ... the only one that makes any noise (and just barely) is V4.
Then I swapped the whole preamp (5 - 12AX7's) with a set from a fellow on Reverb.com (swears they're fine.) I still have the hiss. And this: The new tubes added a little 60hz hum.
And again, if I tap the preamp tubes the only one that makes noise (and just barely) is V4. This happens with either tube in there (new or the old.)
The only difference I really notice (ignoring the 60hz hum) is that with the new tubes in the pre-amp - swapping to 50W mode, the hisss and hum take a while (more than 30 sec?) to "build in" and then seem much lower in volume.
Totally weird?
Or do I need new 6L6's?
Thanks in advance for the benefit of your wisdom,
