Hi,
I'm repairing/renovating an old tube monaural Hi-Fi amplifier for a friend. It's a low powered amp with 2x 6V6 power tubes, a 5Y3 rectifier tube (and a couple of 12AX7 preamp tubes) and is cathode biased. The amp was not working when my friend gave it to me to fix. The cathode bias resistor on the power tubes is toast and unreadable and unmeasurable.
I cannot find any documentation of any sort on this 1958 manufactured unit and the company has declined to provide any info, documentation and/or a schematic. But OTOH, it's a straightforward power amp and power supply, like many I've seen before. My question: How can I tell if the manufacturer intended this amp to run in Class AB or in Class A. It'll certainly affect how I choose a new cathode bias resistor and how many mAs the power tubes will be pulling.
Thanks for your expertise,
Bob M.
I'm repairing/renovating an old tube monaural Hi-Fi amplifier for a friend. It's a low powered amp with 2x 6V6 power tubes, a 5Y3 rectifier tube (and a couple of 12AX7 preamp tubes) and is cathode biased. The amp was not working when my friend gave it to me to fix. The cathode bias resistor on the power tubes is toast and unreadable and unmeasurable.
I cannot find any documentation of any sort on this 1958 manufactured unit and the company has declined to provide any info, documentation and/or a schematic. But OTOH, it's a straightforward power amp and power supply, like many I've seen before. My question: How can I tell if the manufacturer intended this amp to run in Class AB or in Class A. It'll certainly affect how I choose a new cathode bias resistor and how many mAs the power tubes will be pulling.
Thanks for your expertise,
Bob M.
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