[Boatanchors] Rookie Question

[Glen Zook via Boatanchors]

In the NC-200 the headphone jack is off the plate of the "audio inverter" which is the driver to the push-pull 6V6 tubes.  This is unlike many receivers where the headphone jack is off the audio output transformer.  Therefore, removing the 6V6 tube will still allow audio to the headphones.  In fact, the audio level may increase because the load from the audio output stage is removed.
The original speaker had the audio output transformer mounted in the speaker housing and the B+ was run to a center tap in the transformer and each side of the primary was run back to the plates of the 6V6 tubes. Glen, K9STH

Website: http://k9sth.net
      From: BB <billball0 at comcast.net>
 To: Boatanchors at mailman.qth.net 
 Sent: Saturday, March 14, 2015 5:32 PM
 Subject: [Boatanchors] Rookie Question
   
Joe - I don't have the schematic, but if you pull the 6V6s, you won't have any audio to
drive the earphones with - (Unless there is a separate circuit for the phones.) 

And stringing the audio transformer at the end of a 5 foot cord
means a few hundred volts out on a wire - not a real good idea, unless the original
speaker was wired that way.  Old speakers used the high voltage fed through the electro-
magnet coil to power it.  Using a new permanent magnet speaker, you can just run the 
audio output from the transformer through speaker wire to the speaker.