TM79 Assembly Guide |DIYRE Manuals

Safety Precautions, Warranty, and Disclaimer Improper soldering and handling of electricity can cause serious injury and damage to your property. Read and understand the instructions below before beginning your project. Follow the instructions, build carefully, and use the appropriate tools. Build at your own risk. DIY Recording Equipment, LLC is not responsible for any damage or injury resulting from the assembly or use of your kit. You are the manufacturer of your kit. It is your responsibility to turn this group of parts into a working piece of recording equipment. DIY Recording Equipment, LLC does not guarantee the success of your project and disclaims any Implied Warranty of Merchantability. Please visit the support forum for assembly support.
Damaged or Missing Parts All kits and parts are checked before being shipped to you. If something arrives damaged or if your kit is missing a part, please open a support ticket to inquire about a replacement. Missing parts will be replaced at our expense. Damaged parts should be returned for verification. If the part shows signs of use beyond what was necessary to determine that it was damaged, DIY Recording Equipment, LLC reserves the right not to replace the part.

Standoffs and Header (Bag 1) top

Insert Standoffs top

Note that there are two different ends on the plastic standoffs. The locking end has tabs with a right angle to prevent them from being removed after installation, while the non-locking end has smooth tabs. Insert the locking ends of the standoffs from the bottom of the PCB.

Populate 8-Pin Header top

Insert the 8-pin header into the holes marked “CON1.” Make sure to place the short, silver pins through the bottom of the PCB so that the PCB rests on the black plastic posts. Solder the header from the top of the PCB and do not trim the leads afterward.

Tape and Solder IC Socket top

Insert the IC socket so that the notches on the sockets align with the markings on the PCB. Secure in place with tape. Then flip the PCB over and solder in place. Remove the tape.

Resistors (Bag 2) top

Bend Resistors top

Bend the resistor leads 90 degrees at the body so they can be inserted into the PCB.

Sort Resistors top

Resistor sorting made easy! Enter a value to find the color bands, or enter your color bands to find the resistor’s value. Type in the value of the resistor you need and this tool will show you the corresponding color code.

Place Resistors top

Place the resistors into their respective positions on the PCB. As you place each resistor, bend its leads against the bottom of the PCB so that it stays in place during soldering.

Solder Resistors top

Solder the resistors to the PCB. Observe good soldering technique: heat the pad and lead for 2-3 seconds, apply a small bit of solder, and continue to heat the pad for another 2-3 seconds. The finished joints should be shiny and should have just enough solder to cover the pad entirely.

Trim Resistors top

Use clippers to trim away the excess leads. Clip as closely as possible to the joint without clipping the joint itself.

Capacitors and Transistors (Bag 3) top

Populate Small Capacitors top

Place the smaller capacitors in their respective places. These capacitors are not polarized and therefore can be placed in either direction. Solder then trim the leads.

Populate Large Capacitors top

These capacitors are polarized, so they must be placed in a certain direction. The positive lead is slightly longer, while the negative lead is marked with a stripe on the body of the capacitor. Place the capacitors with the positive lead in the pad next to the "+" marking on the PCB. Double check their orientation, then solder and trim.

Populate Transistors top

There are two important things to note about transistors. First, the orientation: one side of the body is flat while the other is round. And second, the part number: carefully check the markings on the sorting sheet against those on the body before inserting them.

Identify the transistors, place them in the correct positions orientation, double check, and then solder and trim.

Transformers (Bag 4) top

Place Transformers top

Place the transformer in the X1 and X2 positions. Note that there's a small notch in the plastic near pin 1. Line this notch up with the corresponding one on the PCB, then solder the transformer to the PCB. To prevent damaging the transformer, leave 20 seconds between solder joints. This allows the coil wires time to cool down between joints.

IC (Bag 5) top

Place IC in Socket top

The leads of the IC must be slightly bent to fit perfectly into the sockets. Press one row of leads against a flat surface until they form a 90-degree angle with the body of the IC. Then do this for the other row.

IC polarity is indicated by a dot or notch on one side of the body. Align this side with the notch in the socket. Place the IC in this direction, and press it completely into the socket.

Final Checks top

Before you wrap up, check the following things:

Capacitor orientation: Is the stripe on the cap on the opposite side from the "+" marking on the PCB?
Resistors: Are all the resistors in the correct positions?
IC orientation: Does the dot/notch on the IC align with the notches on the socket and PCB?
Transistor orientation: Does the shape of the transistor match the outline on the PCB?
Soldering: Is every solder joint shiny and clean? If one is cloudy or misshapen, try reheating it for 8 seconds and adding a tiny bit more solder.
Trimming: Are all of the excess leads trimmed down as close to the joint as possible?

Finished! top

All good? Congrats on finishing your build! Have a question or problem? Drop us a line.