I just got this off CL a few days ago, but wasn't able to fire it up until today. Tubes look to be original from around 1961 or so. It was sounding pretty damn good, but I noticed that one of the right power tubes was red-plating a bit, so I shut it down. I'll have my tech take a look at it in a couple days. It uses 6BM8 power tubes. It reminds me of early Sansui styling. As you can see, it has no corrosion whatsoever... near mint condition throughout. All lights are working too. I love little amps like this...