Auto ignition coil as output transformer

[Greg Hyatt]

Attached are load lines for a typical output tube. Both pentode and triode connection are shown. Both are at 250V B+ and -25V bias. the DC load line is in green (the coil has 10k resistance) and the AC line is in black.

What happens in the transition from DC load to AC load? as you crank the volume does the load line rotate with gain and HD changing?

I calculate 2.2% HD for the AC curve of the triode, but very low power of .3W, which is OK for headphones but nothing else.

 

[JMFahey]

Don´t WASTE time with a weakling ignition coil, if you are going to do it at all, do it well, like my friend Dr Steve Conner, from University of Glasgow High Voltage Laboratory:

YouTube

 

[JMFahey]

For the impatient ones with the short attention spans, here´s just the Guitar playing bit:

YouTube