Mk3 Output Transformer Extra Wire

Working late last night on the pair of Dynaco MK3's I noticed and extra wire coming out of one of the Output Transformers. Looked at all the rest and none had the extra White Wire. It's connected on the output side (speaker) and seems to be about 30ohms from black to this white wire.

Was this from a different model amp or an early version? I couldn't find anything in the M3 schematic that shows this tap.

Sandy

Thanks Bob, I have a few pics of the old chassis that is came out of but I can't see where it goes. It might have been coiled up in the bell of the transformer and didn't notice it when I tore them down.

Sandy

Sandy,
I have a pair of these amps...The manual say's:

The Dynakit Mark III-70 is identical to the Mark III with the addition of a 70 volt
output for line distribution systems. A different transformer (A-431-70) and a five
screw terminal output strip are the only variations.There is an additional white wire
coming out of the output transformer. This should be connected to the fifth terminal.

Obviously, this transformer is mounted on the more common Mark III chassis having only
the four screw terminal. You can just terminate this lead. (tape off)

Manual further states: The use of the (4)( and (16) ohm outputs is unaffected by the
presence of the 70 volt output. The output impedance of the 70 volt tap is 83 ohms.
When the 70 volt output is used, there are commercially available loudspeaker matching
transformers designed specfic for this application delivering up to 60 watts continous
rated power.

I should note that original chassis for this model had a wider cutout to mount the
five screw terminal strip. The fifth screw position was screened as 70V.

Kevin @ Dynakit

Don't know how that "Happy Face" got inserted in the copy...Should have been an (.

LOL....Kevin

Thanks Kevin!

Yeah, watch out when using parenthesis