I would have loved to start with the background of my built, pictures and lessons learnt, but I have hit a brick wall requiring urgent assistance from the astute builders that have helped me a great deal through reading the forum. Trust me I have been through a lot but managed to find solutions from the forum. So I am at a stage where I feel I have to ask before taking certain decisions. I am at the initial set up stage for the second time (after having the perfect one and blew it by a stupid mistake - swapping the unregulated polarity and blew the whole thing up). Had to replace a lot of components and the circuit is stable i.e. no more smokes or excessive heat.
1. Unregulated Voltage = +45.1V and -45.2V
2. Regulated Voltage = +37.3 and -37.1V
3. Input stage bias setup: easy to set to 4V
4. VAS stage balance setup: can attain 130mV balance for a short while but very unstable fluctuates, in fact, all the other steps start to behave this way and couldn't even move to Null the output DC offset.
I have tried to swop Q1, Q3 put them back and tried Q2, Q4 I have cannibalized the other channel (by the way the other channel is now dead from cannibalism

) hoping that the JFETs are still intact. Still no luck. However, when I analyze the behaviour of the various combinations I am inclined to conclude that the issue is with the JFETs (some behave better in that the fluctuations are much more stable than others but still there nonetheless) . Could this be correct? If so I intend ordering new freshly matched Quads (from AMB). By the way, I am building Monoblocks.