Hi guys,
Last year I purchased my dream amp, a used (obvi) Mark IVB wide head. It was in real rough shape, and you can see from the pics where it started and where I got it to in terms of restoring it.
Before
After
I took it to my amp tech when I got it to not only put it back in the original headshell but give it a thorough look-over and fix any problems it might have.
He had to replace a preamp tube, resolder a couple pots and re-seat the reverb leads, and after another playtest everything seemed fine. I haven't had a chance to gig with it yet because I'm still putting together a stereo rig that includes it and my Marshall Silver Jubilee, so it's just been living in my office and I've been practicing through it at low volumes (the lowest it seems capable of) since I've got it. So tweed power, triode and Class A are all selected, and I have the master volume basically as low as I can get it to go with it still making sound. (I'm not sure if it's natural for this amp to be so tricky to dial in a low-volume level, my Marshall is a 25/50w head so the Mark IV has quite a bit more muscle to flex than what I'm used to).
Anyways, it's recently developed an issue where after I've been playing for a while the volume level will start to rise and fall gradually, and seemingly randomly. I'm not sure if this is a tube issue, or if the amp is somehow switching itself between full power and tweed power or something like that. Anyways, I figure I probably have to bring it back in to my tech, but since pretty much everyone is closed these days, I figured I'd ask the community here for any advice in the mean time.
Here's a link to the first vid that I recorded with it during quarantine just for fun.
https://www.youtube.com/watch?v=74_CdaNmitU
Thanks so much for the help,
-Josh
Last year I purchased my dream amp, a used (obvi) Mark IVB wide head. It was in real rough shape, and you can see from the pics where it started and where I got it to in terms of restoring it.
Before
After
I took it to my amp tech when I got it to not only put it back in the original headshell but give it a thorough look-over and fix any problems it might have.
He had to replace a preamp tube, resolder a couple pots and re-seat the reverb leads, and after another playtest everything seemed fine. I haven't had a chance to gig with it yet because I'm still putting together a stereo rig that includes it and my Marshall Silver Jubilee, so it's just been living in my office and I've been practicing through it at low volumes (the lowest it seems capable of) since I've got it. So tweed power, triode and Class A are all selected, and I have the master volume basically as low as I can get it to go with it still making sound. (I'm not sure if it's natural for this amp to be so tricky to dial in a low-volume level, my Marshall is a 25/50w head so the Mark IV has quite a bit more muscle to flex than what I'm used to).
Anyways, it's recently developed an issue where after I've been playing for a while the volume level will start to rise and fall gradually, and seemingly randomly. I'm not sure if this is a tube issue, or if the amp is somehow switching itself between full power and tweed power or something like that. Anyways, I figure I probably have to bring it back in to my tech, but since pretty much everyone is closed these days, I figured I'd ask the community here for any advice in the mean time.
Here's a link to the first vid that I recorded with it during quarantine just for fun.
https://www.youtube.com/watch?v=74_CdaNmitU
Thanks so much for the help,
-Josh