BlakemoreMusic
Member
Hey friends,
looking for a little guidance. I recently traded for a Roadster from a forum member and I'm learning the quirks of this particular amp and am thinking something may have happened during shipping.
The amp is running JJ EL34L's and Tungsol 12ax7 in V1.
My problem(s)-
-when I switch to Spongy mode, i get a 120Hz hum. It is especially noticeable on channels 3 and 4 as they amplify more gain stages than channels 1 and 2. The hum is there in 1 and 2 as well if I turn up there masters to listen for it. If I turn whichever channel master down all the way, the noise stops. This tells me its in the preamp section, pre-master. In bold mode there is no hum. Spongy there is hum. Preamp tube rolling has not changed the hum at all. Removing the rectifer tubes, changes nothing. Hum is present in all modes and configurations.
-I get 60z hum on channel 4 in both bold or spongy
-channel one has hiss/fizz in the background. Definitely has the campfire sound. Probably a resitor/cap combo going bad
- I get a nice "thump" through my speaker cab when changing channels. I am familiar about the roaster pops, this is different and much lower in frequency. Ive never had a mesa do the "thump" thing before.
Any thoughts or insight are much appreciated.
looking for a little guidance. I recently traded for a Roadster from a forum member and I'm learning the quirks of this particular amp and am thinking something may have happened during shipping.
The amp is running JJ EL34L's and Tungsol 12ax7 in V1.
My problem(s)-
-when I switch to Spongy mode, i get a 120Hz hum. It is especially noticeable on channels 3 and 4 as they amplify more gain stages than channels 1 and 2. The hum is there in 1 and 2 as well if I turn up there masters to listen for it. If I turn whichever channel master down all the way, the noise stops. This tells me its in the preamp section, pre-master. In bold mode there is no hum. Spongy there is hum. Preamp tube rolling has not changed the hum at all. Removing the rectifer tubes, changes nothing. Hum is present in all modes and configurations.
-I get 60z hum on channel 4 in both bold or spongy
-channel one has hiss/fizz in the background. Definitely has the campfire sound. Probably a resitor/cap combo going bad
- I get a nice "thump" through my speaker cab when changing channels. I am familiar about the roaster pops, this is different and much lower in frequency. Ive never had a mesa do the "thump" thing before.
Any thoughts or insight are much appreciated.