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Old 06-05-2013, 09:36 PM
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cbenham cbenham is offline
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Quote:
Originally Posted by VintagePC View Post
Okay, here's where I'm going to need some info from the more experienced folks.

I had a look at the TV chassis and schematic to double check that it matches before I go ordering parts and find out there's a major discrepancy

There's one thing I found that is off - in the schematic, V8 is marked as a 6W6 and has the first audio stage coming in on pin 5. However, in the chassis, this is wired to pin 6 of the socket, and I found not a 6W6, but a 6V6 instead.

A quick search says they're pin-compatible but not exactly interchangeable, any thoughts on this?
There is no connection to pin 6 on either the 6V6 or the 6W6. Pin 5 is the control grid in both tubes. Sometimes pin 6 on the socket for these tubes is used as a tie point for a resistor or a cap to pin 5, just for the sake of convenience.
If the output transformer is original it may have a 2K to 4K primary impedance, great for a 6W6 but NOT for a 6V6. The 6V6 wants a transformer with a primary impedance of 5K to 6.5K.
Also a 6V6 used with a 2K to 4K transformer will make lots of nasty sounding distortion.

Hope this helps get pretty sound from this set.
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