14. Install R1, a 1K ohm resistor
15. Install R2, a 1K ohm resistor
16. Install R3, a 100 ohm resistor
17. Install R4, a 1K ohm resistor
18. Install U1, the other LF347 quad opamp. Again make sure you orient it correctly! It is in the same orientation as the last part. Dimple indicates the pin 1 end. Check to make sure all pins are through, then solder all 14 pins!
19. Install C7, a 10 uF electrolytic capacitor. Note that electrolytic capaci- tors are polarity sensitive. This means they wont work if put in the wrong way! That is why we have indicators on the layouts indicating the positive side of the capacitor. Usually the capacitor itself is marked on the negative side. We don’t do this to confuse you, but that has been the standard for years so we aren’t about to change it now. Just make sure that the side NOT marked negative is in the same side marked positive on the board.
20. Install C8, another 10 uF electrolytic capacitor. Again check polarity.
21. Install R14, a 10K ohm resistor
22. Install R13, another 10K ohm resistor
23. Install C4, a 10 uF electrolytic capacitor. Note orientation!
24. Install C1, another 10 uF electrolytic capacitor. Make sure the negative pin is not in the positive hole!
25. Install C6, a 100 uF electrolytic capacitor. Again note orientation for this and all of the rest of your electrolytic capacitors! This will save you from having to read “orientation” six more times.
26. Install C5, another 100 uF electrolytic capacitor.
27. Install C3, a 100 uF electrolytic capacitor.
28. Install C2, a 100 uF electrolytic capacitor.
29. Install VR1, the 78L12 +12 regulator. Yes, this looks like a transistor but it’s not. In fact has many transistors and a special Zener diode inside. Make sure the flat side of the part is installed as shown on the diagram.