I ordered the biasmaster +4 octal probes, from the tube amp doctor, in germany so i can check every tube one by one, and bias on the highest current drawing tube, it's a nice tool to have.
I did have a loose solder joint on the board, at the connection that comes from the power transformer, also look at the big connector that goes to the power board for some burn marks j14 and j15 is the plate and screen, but so far i have no burn marks jet.
The 9oo mk iii is made from1990/1993 the dual reverb is made from 1990/present day, the slx made from 1993/1999. The official changeover to 5881,s took place on Marshall 's production line on August 12,1993, and all 5881 powerd products were indicated by a front panel sticker. In simplistic...
It was offered as both a combo and a head, named the 1923c 85th anniversary and 1923 85th anniversary models respectively to commemorate Jim's year of birth.
No noise on the red channel low tune guitar's dail your gain,noon on the red channel you use a noise gate, Its not sounding like a 5105 iii el34 sound nothing like it ,all of your amps sound the same.