Tube service life in Melonan jukeboxes

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W klubie od: 21/02/2022

Greetings. Meloman jukeboxes have "instant on" feature. Tube heaters are always on while the machine is connected to mains. Plate voltage is applied by a relay only during playback of a record.

Running a tube with only heater on for prolonged periods of time causes "cathode poisoning". During a typical business day, when a cafe with jukebox installed has low count of visitors, tubes run in this mode most of the time.

How did this affect tube service life in Meloman jukeboxes? How often did owners of these machines have to replace tubes? How often were solid state amplifiers installed in them? Thanks.