The plan with this headphone amp is to build it on a breadboard first. Partly to make sure it works, and partly because I’m still hesitant to etch my own circuit board.
Since the tube wasn’t going to fit on the breadboard, I was looking for something to attach it to, temporarily, so it won’t flop around. I found a cigar box in my small junk collection, which I think will do nicely. I mounted the tube socket on the cover and soldered in some hook up wire.
Even though it is meant to be temporary, this little cigar box could function as a permanent enclosure. It will need some ventilation holes though.