TM79 Assembly Guide

For recommended tools and safety precautions, refer to the Colour Palette Assembly Guide.

TM79 is a multi-stage saturation Colour designed by Eisen Audio for DIYRE. Although the TM79 packs a lot of parts into a compact layout, assembly involves only simple, board-level soldering.

Table of Contents:
Sort Components

Before you begin soldering, identify each component in the kit and sort them into piles of like components. Use the color codes shown to the left to identify the resistors.

Part # Value Description Qty
R2, R3, R6, R14 220k Resistor, 1/4W, metal-film 4
R7, R9 10k Resistor, 1/4W, metal-film 2
R10 68R Resistor, 1/4W, metal-film 1
R4, R5 82R Resistor, 1/4W, metal-film 2
R12 750R Resistor, 1/4W, metal-film 1
R11 910R Resistor, 1/4W, metal-film 1
R13 3k Resistor, 1/4W, metal-film 1
R8 5.1k Resistor, 1/4W, metal-film 1
CON1 8-pin Dual-row header 1
- Standoff Nylon, press-fit, 1/8" 4
C7 22p Capacitor, ceramic 1
C1, C2 .1u Capacitor, film 2
Q1, Q2 2N7000 Transistor 2
C6 3.3n Capacitor, film 1
C8 10n Capacitor, film 1
C5, C9 47u Capacitor, electrolytic 2
C3, C4 100u Capacitor, electrolytic 2
U1 CA3240EZ Opamp, dual 1
T1, T2 TY-250P Transformer 2
Standoffs and Connector
Press the four standoffs into the mounting holes. The standoffs have two different sides: a locking side with notched tabs and a press-fit side with sloped tabs. Press the locking side into the TM79.
Solder Connector
Now lay the PCB and standoffs on top of the 8-pin connector CON1. Solder the connector to the PCB from the top.
03_Bend_Leads (1)
Insert and Bend Resistor Leads
Insert the resistors into their respective places as indicated on the PCB. Bend the leads against the PCB bottom so that the resistors stay in place when you flip the board over for soldering.
Solder and Trim Resistors
Flip the PCB over and solder the resistors to the PCB. Once the solder has cooled, trim the excess leads down to the solder joint.
Populate Remaining Components
Populate the rest of the PCB, progressing from the lowest-profile components to the highest. You may want to split this up into three rounds of components of similar height:
  1. U1 (opamp), C7 (yellow, note that the actual value is "22p" not "33p" as marked on the PCB)
  2. C1, C2, C6, C8 (box capacitors), Q1, Q2 (transistors)
  3. C3, C4, C5, C9 (electrolytic capacitors), T1, T2 (transformers)
Note that the transistors, electrolytic capacitors, and transformers must be installed with a certain orientation. For transistors Q1 and Q2, the orientation is indicated on the PCB by the round and flat sides of the component body. For transformers T1 and T2, orientation is indicated by semi-circular notches on the PCB that match those on the white plastic beneath the transformer's steel laminations. Finally, the polarity of capacitors C3, C4, C5, and C9 is indicated on the PCB by a + and a square pad for the positive lead. The negative lead is indicated on the capacitors themselves by a stripe containing "-" symbols.
Congrats! Your TM79 is complete and ready for your Colour Palette. If you've had any trouble with your build, please open a support ticket and we'll be happy to help you:

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