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I found this Moog Prodigy synthesizer schematic that I'm trying to figure out how it works in order to learn more about how electronics work.

What do the circled symbol at the top of the schematic mean ?
What does "N.C" mean ? An example of it is located at the far right.
What does the "*" next to R2 mean ?
What does the "1%" next to R5 mean ?
What does -9V and -12V mean ?
What does the arrow next to R14 mean ?

enter image description here

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  • \$\begingroup\$ top sliding switch is for "Octaves" n.c. means no conecction ( spare) 1% means tolerance, wiper is for Trimpot, 7-9V is bias adjustment from trimpot, R1*, R2* star refers to a footnote somewhere probably says use low noise metal film only. -12V is a supply rail \$\endgroup\$ – Tony Stewart Sunnyskyguy EE75 Oct 13 '16 at 2:57
  • \$\begingroup\$ So in real life those would all be single wires running from the power supply port that the power supply box plugs in to which plugs into a wall socket? I should probably learn about power supplies first but if you could offer insight on how supply rails work \$\endgroup\$ – Bob Saget Oct 13 '16 at 3:33
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    \$\begingroup\$ Someone else posted the same drawing, with some of the same questions, a couple of days ago. Is this a class assignment? \$\endgroup\$ – Peter Bennett Oct 13 '16 at 4:45
  • \$\begingroup\$ No, this is strictly a personal thing. That would really surprise me if figuring out a Moogy Prodigy is a class assignment. That would be really awesome though, someone link me that school he's going to. \$\endgroup\$ – Bob Saget Oct 13 '16 at 7:26
  • \$\begingroup\$ @PeterBennett - Interesting... For anyone who wants to see it, that question a few days ago with the same schematic is: "Can't identify these elements in this schematic" \$\endgroup\$ – SamGibson Oct 13 '16 at 8:39
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The item in the top left is a 2-pole switch that has 3 positions (32', 16', 8'). In the top right, NC means no connection. The 1% is the tolerance of resistor R5. R14 is a potentiometer (variable resistor). The arrow is the wiper arm of R14. The -12V is the voltage powering that part of the circuit. The voltage (-9.0V) at the output of U2B is either for purposes of troubleshooting or for an adjustment. The meaning of the star above R2 is probably explained in a note somewhere else on the schematic.

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  • \$\begingroup\$ Thanks so much that covered literally everything. I now understand everything in this part of the schematic! \$\endgroup\$ – Bob Saget Oct 13 '16 at 2:57
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The schematic shows "nominal" voltages at many points. U1 pin 1 and 3, U2 pin 1 and 7, R14 top and bottom, etc. Those are typically voltage measurements (relative to ground) at key points in the circuit when it is operating as designed. They allow you to probe around the circuit to discover where there may be a problem. They are the voltages shown in the smaller font. The voltages shown in the larger ("normal") font are power supply rails.

The switches are boldly labeled as "SWITCH" and the adjustment potentiometers (pots) are labeled as "TRIM". None of those symbols are "deprecated". Perhaps you just need additional experience reading them.

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  • \$\begingroup\$ Thanks very much, you are right I do need more experience, though I thought potentiometers usually look different than that. \$\endgroup\$ – Bob Saget Oct 13 '16 at 7:28

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