These are very nice amps. Sound good on every type of speakers I tried. Worst cosmetic defect is the scuff on top of one power trans. One of the power cords has tape but still works ok. Some parts replaced over the years.I never had them serviced. One power trans has leaked some tar. It does not run any hotter than the other amp. In my experience this is not a sign of trouble, but more likely the tar compound used.
They work fine, but no guarantee on 60+ year old electronics. The item "Nice Pair Good Working Altec A340A Monoblock Tube 6550 Amplifiers" is in sale since Friday, February 7, 2020. This item is in the category "Consumer Electronics\Vintage Electronics\Vintage Audio & Video\Vintage Amplifiers & Tube Amps". The seller is "kinkless" and is located in Manchester, New Hampshire.This item can be shipped to United States.