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Copyright
2008 FiveFish Studios
www.fivefishstudios.com
SC-1mk2 Microphone Preamp Kit
STEP 13: Solder the Grayhill selector switch. You really need a magnifying glass to make this work easy and accurate. The pins
are very close together and you don’t want to short these pins… otherwise, your gain dB steps will be all wrong.
Build Notes:
a. Solder one of the end pins of the Grayhill switch, and then check if the switch is still flushed to the board, straight and not
crooked. . If crooked, re-heat the pin and straighten the Grayhill switch while the solder is melted. (DO NOT STRAIGHTEN THE
COMPONENT AFTER THE SOLDER BECOMES HARD. You’d risk ruining the PCB or breaking the part.)
If the part is flushed and straight (look at it from all angles), then solder another pin located on the opposite side. Check if the
device is still flushed and straight. If it is, then solder the remaining pins.
b. Installing the stop pins. The Grayhill switch will come with a metal stop pin rod, and a sticker to keep this rod in place. Use
tweezers to hold this pin rod and push it inside the 12:00 position hole as shown in the photo below. Then put the sticker over
it. The pins may not go all the way in, that’s fine. Re-attach the washer and the nut and tighten the nut by hand. This will push
the pin side and the sticker will keep it in place.
If you lost the included stop pins, don’t worry. Just use some cut leads from a resistor.
STEP 14: Solder the LED to the PCB. Observe proper orientation of the LED. Otherwise, the LED lamp will not light up.
Build Notes:
a. One leg of the LED will be longer than the other leg.
b. The LONGER leg of the LED is soldered nearest the Grayhill selector switch (i.e.
long leg = top position)
c. You need to bend the LED leads to form a right angle as shown by the photo on
the right. Set the height of the LED so it is aligned with the DPDT switch. Again, solder one leg of the
LED and see if the height is correct before completely soldering the other leg.
STEP 15: Insert the IC chips, IC1, IC2, IC3 and IC4. Be careful inserting the chips, and make sure all pins go in properly into the IC
socket holes.
Build Notes:
a. ANTI-STATIC WARNING: Ground yourself before handling the chips. Touch a metal gear to
discharge any static electricity on your body. Avoid touching the metal pins of the IC chip. If you
have a wrist ground strap, use it.
b.
Perform the pre-flight check adjustments first before inserting IC chips IC1 to IC4. See
PRE-FLIGHT CHECK Section below.
