Four Classic API preamps for my lunchbox. Super easy DIY kit builds and they sound great!
I bought an old Altec 8-channel preamp/preamp for next to nothing. In stock form it's not very useful: it has fixed gain optimized for speech and gets easily overloaded. I modded it with variable gain, direct output attenuator and -20 db pads on each channel. Now it's a great preamp filled with transformer goodness!
I needed a attenuator for my Daking IV preamp which has very a very hot output, but I didn't want to use regular voltage dividers because that would change the impedance/frequency response, so I simply used four of these inside a 19" rack. A great easy build / low cost solution. :)