KLUDGE@AGCB8.LARC.NASA.GOV (05/31/90)
This evening, I had invited a girl over to listen to some music. For the last month or so, I had been noticing some microphonics from the right channel of my HK Citation II, and had been meaning to replace the 6550's on that channel. Seeing as how Revox was charging me several hundred for the repair of my A77, and my car was losing immense amounts of power steering fluid, I tried to put off replacing them until I had enough cash. Bad move. I went into the kitchen to make tea, and was interrupted after a short time by a 60-cycle hum and a much louder scream. When I returned, I discovered one of the 6550's glowing red hot, and large quantities of grey smoke issuing like a geyser from the vent holes around it. The 15-ohm resistor had become a bad-smelling vapour. The good news is that I found a 15-ohm one-watt resistor in the junk box (a legacy from a transmitter I once owned that ate 833 tubes and their cathode resistors like popcorn), and a call to a local electronic place revealed that they had RCA 6550's in stock, as someone had ordered a pair for a Marshall guitar amp many years ago and never picked them up. Within two hours the amp was back on line although the girl hasn't been seen from in a while. Priorities. --scott