Ramsey Electronics STC1 Instruction Manual - page 12
STC1
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board before soldering, and that the notch or dot indicating pin one of the IC
is in the same orientation as shown on the parts layout diagram. Double
check your work when you are done.
27. Install R50, a 1K ohm resistor (brown-black-red).
28. Install R25, a 10K ohm resistor (brown-black-orange).
29. Install R26, a 10K ohm resistor (brown-black-orange).
30. Install R30, a 10K ohm resistor (brown-black-orange).
31. Install R7, another 10K ohm resistor (brown-black-orange).
32. Install R5, a 10K ohm resistor (brown-black-orange).
OK, before we get ahead of ourselves here, we are going to go back to where
we began and begin to install some of the larger components. At this point you
may want to check your assembly to make sure you have no solder bridges or
cold solder joints.
33. Install C3, a 10uF electrolytic capacitor. Make sure and mount this part
in the correct direction! If you look at the component you will see a stripe
down one side, usually indicating the negative (-) terminal of the
component. You will notice on the parts layout diagram that the hole for the
positive terminal is denoted, not the negative one. You will want to install
this component with the positive (+) lead in the same orientation as shown
in the parts layout diagram. If you do not install it correctly, you will end up
with all sorts of problems in the circuit.
34. Install C21, another 10uF electrolytic capacitor. Pay close attention to
polarity! These two capacitors you have just installed are called coupling
capacitors in this circuit. They prevent the DC voltages seen in this circuit
from being placed upon the jacks, and then sent to your musical source.
They only allow the audio frequencies to pass and be worked upon.
35. Install VR1, one of the 7805 5 volt regulators. Notice on the diagram the
orientation of the flat side of the device. The flat side should be facing in the
same direction as shown after installed.
35. Install VR2, the other 7805 5 volt regulator. Again note its orientation in
comparison to the parts layout diagram.
36. Install C39, a 100uF electrolytic capacitor. Notice the orientation since
this capacitor is part of the power supply and will not do its job if inserted
backwards. This capacitor helps “smooth” out the noises and ripple in the
power supply so that it isn’t as apparent in the audio.
37. Install C42, a .01uF ceramic capacitor (Marked 10n, .01, or 103). Note
that these capacitors are not choosy in what direction they are installed.