Page 6
Tolerance (gold = 5%, brown = 1%)
Multiplier (# of 0
ʼ
s)
2nd digit
1st digit
Resistor Color Codes
Black = 0
Brown = 1
Red = 2
Orange = 3
Yellow = 4
Green = 5
Blue = 6
Violet = 7
Gray = 8
White = 9
3rd digit (only on 1% resistors)
For example: green (5), blue (6), orange (3 zeros), gold
(5%)= a 56000 or 56K ohm, 5% tolerance resistor.
For example: violet (7), green (5), black (0), red (2 zeros),
brown (1%)= a 75000 or 75K ohm, 1% resistor.
Diodes:
Insert and solder the diodes: Note the orientation.
PCB Symbol
Diode
Resistor Networks:
Observe the orientation. There will be a dot on the PCB and one on the network.
IC Sockets:
These will have a keyway or dot (pin 1) to indicate the correct orientation. Insert the socket and bend one leg
at two opposing corners 45 degrees or so. Solder these two pins and check to see that the socket is flush with the board.
Then solder all the pins.
Jacks:
Load the 13 jacks into the PCBs. Since these will have to go through the front panel later, precise mounting is a
must. Carefully insert all jacks and flip each board over.
• Tip:
Keeping the jacks in the board can be challenging but one useful trick is to bend the front pin forwards just a
bit before inserting. Install the front pin first, pushing a bit forward to get the rear pins in place.
Solder
only the front pin
while applying a bit of pressure to the PCB in the vicinity of the jack. Do all the jacks and check
the mounting before soldering any other pins. Close one eye and sight down the row of jacks. Each jack must be flush to
the board and have no tilt from front to back. When everything looks perfect, solder the other pins.
Capacitors:
(
Cap
). There are several different types. You may need a magnifier to read the code on the small ceramics.
• Note that the electrolytic type must be properly oriented. Insert the side which has the
longer lead
closest to the
“+” on the silkscreen. The opposite side of the capacitor
should have a row of “-”.
Polyswitches:
(
PTC
) PS1 and PS2. These have kinked legs and are located on either side of the power input jack.
Power Input Jack:
JPWR; note the orientation as shown by the silkscreen.
Voltage Regulators: 78L05, 79L05 Reference Diode: LM4040AIZ-5.0 Transistors: 2N3904:
These are all in T0-92
packages. Observe the correct orientation.
Trim Pots RT1-RT4
Test Points:
Make loops with resistor trimmings and solder to each test point (TP1 thru TP4).
Wash the PCB in warm water and rinse with distilled or deionized water. Allow to dry. Inspect all work very carefully.
*** Use 245 solder for the remaining assembly steps. ***
Slide Switch:
Install the slide switch on the -1 PCB