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Copyright
2008 FiveFish Studios
www.fivefishstudios.com
SC-1mk500 Microphone Preamp Kit
STEP 10: 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. Use tweezers to hold
this pin rod and push it inside the 12:00 position hole as shown in the photo below. Use the head of a flat-screwdriver
on it’s side to press the pin inside the hole until it is flush. Then put the sticker over it. 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 11: 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 12: 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. Or better yet, use a grounded wrist strap.
Failure to handle the chips properly without the proper anti-static precaution may damage the chips.
