Heath part identification

[Multi-Volti Devices]

Hello:

I have a few Heath transformers I have not been able to identify. Any
help such as model used, etc. would be appreciated.

51-122 Appears to be audio output transformer.
51-158 Could be interstage transformer
51-204 "Base summing transformer". I suspect that should be "BASS" and
it might be part of a
            subwoofer or subwoofer crossover?

Thank you.

Murray
multi-volti at softhouse.com