We'll I've guess we've come to the end of our journey
. The amp is now finished:
I'd say that is a huge difference from what I started with:
I definitely feel much better about the build and it works(3 hours of listening):
A little disappointment as there is some low level hum. I'm not using the HumX devices - and they used to hum and that is why I bought the HumX devices many years ago. I was hoping some of the changes would have avoided hum. Anyhow - it isn't that bad and goes away with music playing.
But I'm super happy with the results - so much better - I took my time and made sure all the wiring was free of burns etc - and super strong fittings - and spaghetti to make sure no open leads anywhere. I'm much more confident of this build vs the old rats nest I had where I always felt that a push on the wires would result in an explosion. This is going to be much more reliable.
Summary of changes:
Heater wires - tightly twisted and routed to the sides of the chassis (note there is a unavoidable heater wire set that goes to the driver board for the driver tubes) - I've twisted the crap out of it - but it is over the section with the components trying to avoid crossing - so no real way to avoid it with this amp. Probably the original wire-routing would have been fine.
Input moved to the front (super short lead from the driver board) (ieLogical recommendation)
Chokes facing each other (ieLogical recommendation)
Used better wiring. Ex 600V 16AWG to ground SCM caps vs 20AWG which comes with kit. I used very little of the 20AWG solid wire as the Tefzel 18AWG/HTFE so much tougher and nicer to work with and higher rated for heat and 600v vs 300v.
Moved switch to rear (ieLogical recommendation)
Changed the power switch to switch on hot lead vs neutral. Hot to tip of fuse. Fuse to switch. Switch to Transformer. Neutral to Transformer.
New caps for SCM module (just replacement no improvement expected) - and SCM module grounded to Star. Note the ground on the IEC is not grounded to the star - but to the corner by the power transformer bolt.
The top mount sockets are nice (Fender drop in) the KT88s now sit right on the black part of the socket - nice and flat vs on the screws. I ordered these by mistake - glad I did (same brand as that of the kit - just top mount.)
Open to ideas to eliminate the low level hum.