Bill and Will's Synth
MOTM 485 Two Dot Oh Construction
"GX-1 Voltage Controlled Filter"


October 2009 -

Why a second MOTM485 page?  Well, we're building another 485, and it's a little different when you're working from a Synth Tech 2.0 thing rather than a full-blown "kit."  So if you feel the need, cross reference this with the KitPage here.

We're going go right into building the thing.

Table of Contents

This page has become really long, so here's a table of contents that we hope will make it easier to traverse:

Parts - presents a Bill of Materials for "two-dot-oh" builders and notes about it

Panel - presents the MOTM format panel

Construction Phase 1 - Resistors, Capacitors, IC Sockets, Power Plugs, MTA headers

Construction Phase 2 - Trimmers, Panel connections

Set up / Testing

Use notes


Will and I have developed a parts-list / bill-of-materials in the form of an XL spreadsheet based on the parts list in the 420 User Guide.

Click here to download the XL spreadsheet (apx. 350K).

Click here to download the .pdf Synthesis Technology parts section of the User's Guide.

Click here to go to our Bill of Materials Page.


If you're building this as a "two-dot-oh" project, we also assume you get the panel from Synthesis Technology:

Construction Phase 1

All the stuff in Phase 1 gets soldered using "Organic" Solder.  At every break in the action, we wash the board off to get rid of the flux.

Resistors, Caps, Power

As usual, whereas we are vigilant about orienting all the resistors, caps, etc. consistently so their values can be read easily (in case we need to trouble-shoot them later), we oriented the resistors with the "tolerance" stripe on the left (relative to the text on the pcb).  We got started doing it this way when we started building our synth and now we do it so all our modules are consistent with each other.  You might want to do it the opposite way - with the "tolerance" stripe on the right.

Some of the caps we got are a little fatter than their corresponding spots on the PCB, but we didn't have any trouble fitting them in.

Semiconductors - Misc - Via Holes

Construction Phase 2

All the stuff in Phase 2 gets soldered using "No Clean" Solder.

Pots, Temco, Wires

the PCB mounted pots and the wires:

We cut the wires like this:

SW1 - 3" bundled triple Blue, Green, White
SW2 - 3" bundled triple Blue, Green, White
SW3 - 3" bundled triple Blue, Green, White
J1 - 7" twisted pair Red, White
J2 - 6" twisted pair Red, White
J3 - 8" twisted pair Black, White
J4 - 7" coax
IN1 - 5" coax
IN2 - 5" coax

time for the tempco resistor

Mounting the PCB

Construction Done

Set up / Testing

Use Notes


Bill and Will's Synth Main Page
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The fine Print:
Use this site at your own risk.
We are self-proclaimed idiots and any use of this site and any materials presented herein should be taken with a grain of Kosher salt. If the info is useful - more's the better.  Bill and Will

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