I've shortened and twisted the heater wires and there's a definite improvement. I also moved said wires around a bit which had an audible effect on the hum. I think case solved. So I'm taking your comments about re-mounting this nightmare into a suitable chassis quite seriously. As you can see it's kind of a cluster in there and I"m not sure adequate separation is going to be possible considering current chassis size. I'm sure I can lay this out better from scratch.TriodeLuvr wrote: ↑Mon 04/12/21 12:35 pmI've been looking over the photos you posted, thinking about the additional tube socket. Even with a fair amount of metal working tools and options for bending and cutting sheet metal, it isn't evident to me how you'll add another tube and create an amp that can be bolted into a case. I think you'll eventually need to remove the output transformer and mount everything on a new chassis.
Just to present one option, Lloyd Pans sells square-sided aluminum cake pans that are 14 gauge (.063") aluminum with welded corners. This is heavier gauge than the thin stuff sold by Hammond and probably about the limit for working with hand tools. A 6" square pan in 2" or 3" depth is about $20. They have rectangular pans too, but they're probably much larger than what you need for an amp like this. Anyway, one of these pans would be an inexpensive option if you have tools like chassis punches and a step drill.
https://lloydpans.com/bakeware/cake-pan ... -pans.html
So my first move is always to storage where I may have a suitable candidate. If nothing's there then I'll "pan it"!
It's something I had actually thought about but hoped I wouldn't need to do. But if you're going to do something, do it right. And this point in the project is pretty much the right time too do it.
Thanks for the recommendation and link.