I'm in the middle of re-capping a Marantz 2230 receiver right now. It's not hard - just unsolder the old ones and solder in the new ones. This receiver has 70 electrolytics, so it takes a while, but it is fun. Since the new caps are much smaller than the old ones, I was able to double the power supply capacitance and double the output cap values for more bass and punch. Here's a picture with the main filter cap and output caps replaced - the filter cap is a Panasonic THA, 10000uF, 80V, the output caps are Nichicon KG Gold Tune 4700uF, 80V, bypassed with a 1uF Solen polypropylene. Total parts cost is ~$50 for the entire re-cap and I paid $20 for the reciever at a flea market. Outstanding bang for the buck!!
Marantz 2230 re-cap
Marantz 2230 re-cap