Output transformer w/ 6 taps on the secondary

[invalidcd]

I feel really stupid but Im out of options.

Ive got this OT that I won on ebay it was running a hifi amp w/ 4 12au7 and 2 7868(so i assume 30watts?)(6.6K OT)
ok so my problem is it has six taps and I cant figure out which one is the com/ground tap, dumb i know, but i have no experience with hifi amps.


So if anyone could please help I would greatly appreciate it

Secondary-Taps:

-Orange=.555 vac (16?)
-Green=.396vac (8?)
-Yellow=.298vac(4?)
-Yellow/Black=(com?)
-Black/White=(com?)
-Black/Green

Voltages measured w/ 10vac across the primaries and switching between the Y/BLK and BLK/WHT taps as (com)

[rfgordon]

What you have there was common in office/business application mono amplifier/receivers. You've got three ordinary taps 4/8/16 plus their common/ground (probably yellow/black), and you've got two taps for a 70 volt distributed speaker line, which would have been used to run a bunch of speakers in, say, the ceiling of a retail store.

The tap with the least resistance to the 4/8/16 taps should be it.

Only one of the ____/black will make noise with the regular taps, so if the first one you connect doesn't make noise, try another. Just be quick on the Standby switch if no sound comes out!

[invalidcd]

Thanks Rich