Ah, again a lack of patience makes my results less than what I planned, but I do have a proper panel for my headphone amp now.
To recap, I wanted to be able to just plug headphones into my synth, so I built the dual NE5532 circuit on a scrap of perfboard and cut its original panel out of a cardboard box that held little bags of animal crackers. Since that kind of panel isn't exactly going to hold up to repeated plugging and unplugging of cables into its three jacks, I cut this panel out of a scrap of sheet aluminum, using tin snips to trim a couple of edges but mostly using nibblers, which chip out a rectangle of material roughly 6mmx3mm at a go. I wore a glove on my squeezing hand this time, so it's not all bruised like the last time I tried this, and it went much easier since I didn't need to cut any inside rectangles.
Once I had it cut out and cleaned off, it was too dark to take it outside and spray-paint it, so I grabbed a brush and a little bottle of black modelmakers' gloss enamel paint. I had to practically pour the stuff on to get a thick enough layer to be, y'know, black. Then I set it aside to dry, and when it still looked liquid after an hour, looked it up online to see the proper drying time. 48-72 hours, it said.
(Now, that may not be accurate. This is apparently a very old paint set; the box, containing 9 glass bottles of paint and a plastic tray, has a price printed on it of $4.39 and a copyright notice of 1980, so formulas may have changed dramatically since then. It's at least probably not lead paint, though it would have been made, at least in part, for painting lead figures.)
So I did what any terribly impatient person with a heat gun would have done, and ran it at the thing for five minute bursts for a couple of hours. That was all last night; the paint was dry, if perhaps not completely cured, today (after maybe 20 hours), so I went ahead and mounted the parts to it and put it in the case. It's an interesting glossy effect; it's not entirely opaque, which gives the aluminum a glass-over-metal look that I kind of like. I won't do it this way again, but I'm not displeased.
And of course, it works, which is the important thing. It'll drive either my good(ish) monitor headphones or earbuds, or provide a stereo signal to plug into an effect or recorder that wants such. It's very satisfying.
