Hi Boogie Board,
I bought a new F-50 about a month ago. I love the tone, my standard for clean tone used to be a Fender Twin Reverb, which I played side-by-side with the F-50 in the store. Not much price difference, and the Mesa just sounded better, much more full and authoritative.
The reason I'm posting is that I've noticed, over the past couple of weeks, a popping noise when I switch into standby mode after using it. It started as a minor clicking noise at first, similar to the sound the relays in the channel-switching circuit make the first time the channels are switched, so I didn't think anything of it until the past couple of days, when it developed into a fairly explosive noise. It's not quite at ear or speaker-damaging levels yet, but it'll probably get there if current trends continue. It doesn't happen when switching from 'Standby' to 'On', just the other way. My first thought, as my impression is that the standby function just turns the tubes on and off (except for the heaters), was that it was something to do with the power tubes, so I put the original ones back in (I bought a duet of Mesa 5881s for a bit of a darker sound), but it did the same thing. I noticed as well that the noise is unaffected by the volume/tone controls, but it does sound slightly different based on the currently active channel, and whether contour mode is active on the red channel (so, the noise must be originating somewhere in the preamp). I noticed as well that the inactive channel's LED on the front panel will flash momentarily while the sound happens.
I suppose the next thing to check for is probably a noisy preamp tube, but I don't have any spares, so I don't have a way of doing it at this point. I decided to post here to see if anyone who knows more about tube amps than I do has a better idea of what to check before I call Mesa or buy a 12AX7 to test with.
Any assistance anyone can offer is appreciated.
I bought a new F-50 about a month ago. I love the tone, my standard for clean tone used to be a Fender Twin Reverb, which I played side-by-side with the F-50 in the store. Not much price difference, and the Mesa just sounded better, much more full and authoritative.
The reason I'm posting is that I've noticed, over the past couple of weeks, a popping noise when I switch into standby mode after using it. It started as a minor clicking noise at first, similar to the sound the relays in the channel-switching circuit make the first time the channels are switched, so I didn't think anything of it until the past couple of days, when it developed into a fairly explosive noise. It's not quite at ear or speaker-damaging levels yet, but it'll probably get there if current trends continue. It doesn't happen when switching from 'Standby' to 'On', just the other way. My first thought, as my impression is that the standby function just turns the tubes on and off (except for the heaters), was that it was something to do with the power tubes, so I put the original ones back in (I bought a duet of Mesa 5881s for a bit of a darker sound), but it did the same thing. I noticed as well that the noise is unaffected by the volume/tone controls, but it does sound slightly different based on the currently active channel, and whether contour mode is active on the red channel (so, the noise must be originating somewhere in the preamp). I noticed as well that the inactive channel's LED on the front panel will flash momentarily while the sound happens.
I suppose the next thing to check for is probably a noisy preamp tube, but I don't have any spares, so I don't have a way of doing it at this point. I decided to post here to see if anyone who knows more about tube amps than I do has a better idea of what to check before I call Mesa or buy a 12AX7 to test with.
Any assistance anyone can offer is appreciated.
