pilot: Too many tubes

ID: 418112
? pilot: Too many tubes 
15.May.17 18:48
24

Victor Ford (USA)
Articles: 3
Count of Thanks: 3

The Pilotuner T601 schemetic shows 5 tubes/valves. Mine has a 6th tube under the chassis. A 6C4. Not sure where to go from here. I replaced all caps, and all 6 tubes are good. Just trying to figure out why the 6C4?

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 2
Pilotuner T601 with 6 tubes? 
15.May.17 20:19
24 from 1763

Bernhard Nagel (D)
Officer
Articles: 1685
Count of Thanks: 3
Bernhard Nagel

Hello Victor,

please show some pictures of your Pilotuner T601 to help determine if this is an original factory variant or a later modification.

Thank you.

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pilot: Too many tubes 
06.Jun.17 10:25
316 from 1763

Robert Weaver (CDN)
Articles: 35
Count of Thanks: 2

I've never seen any documentation to indicate that there was ever a version with an added 6C4. I think that this was likely a user modification, not done at the factory. It's not normal for a factory built product to have a tube mounted under the chassis. As Bernhard suggested, a picture would be very helpful.

Off the top of my head I can think of a couple of reasons for adding this tube. The most likely is to get a bit more audio output. The other possibility (less likely) is that it is part of an added AFC circuit.

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