So my rear pre-amp blew out the other day (yes the fuse was good) and when i took it apart one of the large capacitors was burnt. Is this a common thing? What is the output of these little units?

 

Well the preamp is built into the deck. The GXE amp powers all speakers, i'd guess it's 25x4 or something. Replace the cap and see if it works, or just upgrade the whole system. Anyway, 20+ years is a lot for large amp capacitors. In fact I'll be recapping a 30 year old stock amp whenever the replacements arrive. All of them looked good, but was completely dead, until I piggybacked a couple 2200uf from an old motherboard which brought it back to life. After 30 years I'm sure they're all dried up, so I'm doing all 16 on the board. If you're going to try fixing it, just replace them all.