Hi, I know you have been around on the forum for a while, but I would like to share a thought to you and the other diyers who work with tube audio. Please no one take offense.

When building a tube project I find it essential to use a chassis at least 50% bigger than would seem needed. There are several reasons, First, it lets the parts breathe. Cramped chassis lead to heating problems. Second except for RF circuits and really high performance audio circuits I have not found that it is of any benefit to cram parts in closely. True you should not excessively spread them out - so I allow enough room to move things around and on occasion replace parts with ones that might be physically larger. With a bit larger chassis I find that I don't have to compromise layouts as much. It is easier to put things where they make sense. Example, the input tube near the input jack or volume control and not have to worry that one or the other is too close to the power inlet. The larger chassis also makes it easier to trouble shoot the project. Things don't always work like you expected and the extra space makes it much easier to trace the circuit for faults. BTW using colored wires helps a lot too. So I hope these thoughts help someone out there to avoid some problems.
Good listening
Bruce