I built the thing out of NE5532s in the end... Took an age to do, as
all the other components were SMT to fit it onto a really tiny board
which'll fit inside one of those Otter Boxes along with the MD unit...
I don't think the numerous SMD components are even visible on the
underside shot due to the focus being so poor, but I've included it anyway.
As for layout, well, I tend to make it up as I go along... effectively, the
underside could be quoted as 3-layer... :)
As for the components used... all the resistors are SMD 1% bulk metal films.
Power decoupling is 220uF/25V FC+10uF/25V Oscon. Coupling caps are all
2.2uF/25V Oscon except for the blocking ones on output which are Elna