Picked up another AC/DC Colortrak.

[old_coot88]

Originally Posted by Eric H

So if I put 12 vols DC on the narrow set of pins and it runs then it's a dual voltage set.

Wonder which one should be +

Mine measures open circuit, infinite resistance on the narrow-set pins, in both directions whether the power switch is On or Off. Totally zippo. There's no "AC/DC" logo on the front either, even tho the tag on the back says 120VAC, 12V DC.
Interestingly, the wide-set (120VAC) pins measure 24 ohms in both directions, indicating a transformer primary, and it's switched with the power switch. The set's heavy enuff to contain a power tranny, tho i don't remember even looking at the power supply when i had it open 24 years ago to fix the sound.