Did you checked if one of the tubes pins was not crooked or bent ?
Put back your old tubes, maybe something is wrong with your new tubes. It will give you some indications.
Check the sockets solder points, maybe one solder point is crack ? I saw that before in my Fender Deluxe

Hello Cinch welcome to the forum About your concern of Re-biasing this amp you should take a look on another POST that was submit on this forum. http://marshallvintagemodern.com/viewtopic.php?f=36&t=5753 You will find helpfull picture and tips to re-bias your amp. Note that those pictures refer to a...

Nebulozny I guess, at this level it's personnal taste ! I'm using double humbukers too (seymour duncan) on a Charvel San Dimas. You need also to keep in mind that i'm using a Boss multi effect processor (GT-10) and this little box can altern the overall sound of the Amp. But I must admit that I love...

Hello I'm using also a Boss GT-10 this is connected to the amp using the 4 cables method. Also very important, I was experiencing some tone ajustments issues prior re-biasing the amp. One pair of EL34 were at 70Ma and the other pair was at 85 mA right value should be 76mA for both pair. CLEAN BASS 1...

Hey Steeve ! Yeah, I tried some other Amps and they didn't seem to have the same issue. Unfortunately, my problem is intermitent and like when you have a bad tooth pain and you decide to go to the dentist, it stop as soon as you arrive in the cabinet ! I tried to reproduce the issue at the store but...

I will like to know if someone else have the same issue with their MA 100C ? I have sometime, a very lound POP when switching from my Drive channel to the Clean (always from drive to clean and never from clean to drive). I bought this amp this summer and this issue started during the first week. I b...

Nice sound Nebulozny ! You are sure i'm going to try this on my next prartice.