No subject

tube's plate is around 7.5K. 

However from the turns ratio vs output impedance of the transformers listed 
in the service manuals, it appears that the 12A6's plate output-IMPEDANCE 
is around 20-24 Kohms.

I took the turns ratios of the transformer data given, squared that value, then 
used the resulting value to calculate the plate impedance from the output 
impedance. The result in all cases was 20-24 Kohms.

The output impedance from the original audio transformers is as I have 
stated: it depends on the transformer: 8K, 4K, 600 ohms, 500 ohms, 300 
ohms, or 250 ohms.

You can find the necessary data in the original service manuals, or perhaps 
Mike (Morrow) or Mike (Hanz) or even Mike (Everett) will jump in here and 
give us the correct info.

The above is what I have arrived at by comparing what Mike (Morrow) and 
Robert have told me, coupled with reviewing the tube data, and comparing 
the turns ratios that Mike (Morrow) passed on to me/us here.

Ken W7EKB