I have until recently owned and used 2 Audio Innovations 800 mk III power amps (EL34 O/P tubes). Very nice open and detailed amps which are very load tolerant and have a lot more drive than their 25 Watts would have you believe. One excellent upgrade (I did this to one amp) is to buy the Border Patrol outboard power supply, which is a choke regulated P/S unit, which further increases the lovability of the very under rated amps. Ones to look out for are the L2 pre and the P2 phono amps as well as the power amps with the EL34 tubes, all lend them selfs to compenent upgrade if you so desire. But are still excellent in an untouch state, they can still be bought for very reasonable money.