Vintage Rheem Califone Model SA-30 Student Amplifier microphone headphone tape

Description

untested, sold as-is. Vintage Rheem Califone Model SA-30 Student Amplifier.
Has 2 volume controls, one labeled "Program Loudness" and the other "Microphone Loudness", neither of these potentiometers have "stops", (knobs turn from 0 to 10 back around to 0).
There is a "Call Teacher" button, a  "Student Microphone" 1/4" jack, a "Headphones 1/4" jack and a "Teacher Headphones or Output to Tape 1/4" jack. I'm not sure if these unit was part of a reel to reel machine or if this was a remote box set up at a table/desk, etc. There appears to be a back cover that is missing. The circuit has 2 potentiometers, 3 transistors, 11 capaictors and 18 resistors. The circuit board is labeled "Student Amplifier 35-05-04. I am not sure if this circuit is a small preamp for a microphone or a small amp to boost the signal for headphones (I'm guessing the latter) if anyone knows more about this, please hit me up!! Note this unit does not have a power supply, it has a 9 pin connector, note the pins look to me like they are gold plated.
Nice chassis, I think this would make a good chassis to build something in and set into a custom made box. Maybe an EQ? The spacing of the pushbutton and 1/4 jacks seems equal.
Take a look at the other vintage electronics that I have on ebay, much more to come, including more Rheem Califone items !!