SYNTHESIS TECHNOLOGY
PAGE
5
MOTM-110 ASSEMBLY
WWW.SYNTHTECH.COM
don’t worry about that! A soft brush is used to gently scrub the board. We recommend a
‘fingernail brush’, which is about 1” x 2” and be found for about $1.
The other type of solder is called ‘No Clean Flux’,
because as the name implies it does not
require washing. This solder is used on wiring the pots, switches, jacks, etc. This solder is
harder to use on the pc board, because even when melted it is not very fluid (about the
consistency of toothpaste). We will use it VERY SPARINGLY on the pc board.
OK, let’s get started on the board!
PART #1: SOLDERING THE RESISTORS
Since there are more resistors than anything else, we will start here. If you do not know
the resistor color code, refer to the parts list. Resistors are not polarity sensitive, but the
board will be easier to debug (and look nicer) if you point the first color band in the same
direction for all the parts. The color code is also in the README FIRST document that
every customer gets with each order.
Find the
RESISTOR
bag.
Find the MOTM-110 blank pc board. There is a copy (larger than actual size) of the
silkscreen which shows where the parts go at the end of this document. It will be
useful if you locate the part on the print first, put the part in the board, then
‘check off’ the silkscreen. All parts are inserted from the side of the board with the
white silkscreen (the “top” side).
We will stuff the resistors by value to make things easier. The resistors (and other
long-leaded parts) are inserted on 0.4 inch spacings. The important thing is to be
sure that the part is sitting all the way down on the board. Push the leads in the
holes, push the part on the board, and then bend the leads on the bottom outwards
to a 45 degree angle (roughly!). This is called ‘cinching the leads’: keeps the part
from falling out! From the bottom of the board, solder (with the organic flux),
applying heat to the pad for about a half second first, then applying just enough
solder to make a small, flat puddle.
The rule of soldering: don’t use too much, you can always add more! Cut the leads
flush with the top of the solder.
Locate the 56K resistors and solder into R1, R4 & R27.
Locate the 150K 1% (they look different than the others) and solder into R2 & R7.
Locate the 1K resistors and solder into R3, R12, R21, R23 & R24.
Locate the 100K resistors and solder into R8, R9, R11, R13, R14, & R16.
