PMFoundations ER-808 Tom Module User manual

ER-808 – Assembly Guide
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PM Foundations ER-808 v1.4
Tom Modules

ER-808 – Assembly Guide
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Introduction
There are three different Tom modules: Low, Mid and High. They all use the same PCB. You can identify
the three different PCBs by marking with a Sharpie in the L,M,H legend at the corner of the PCB.
Once identified, use the CORRECT BOM for each variant and ONLY INSTALL THE PARTS LISTED IN THAT
BOM, leaving some locations unpopulated and some locations with different values on each of th ethree
variants.
Resistors
Arrange the resistors by value on the workbench in the same order as listed in the BOM and install each
numbered part for that value before moving onto the next.
Install the resistors on the TOP of the board. Take care not to mix up resistors which have similar color
codes. Also be careful not to mix R5 and R9. R9 is next to R30.
Solder and clip the leads.
Diodes
Install the diodes on the TOP of the board. Align the stripe on each diode with the stripe marked on the
board. Solder and clip the leads. Do not mix up signal, power, schottky and zener diodes, some of them
look the same. Now go back and check the polarity against the silk screen for each diode.
IC Sockets
Install the sockets on the TOP of the board. Observe the notch or mark on the sockets and align with
the notch or mark on the board. Solder.
Bus header
Install the 10 pin right angle bus socket on the BOTTOM of the board. This must be installed with the
correct orientation or the module will be damaged when the power is connected.
The cut-out in the socket should face the words "BUS HEADER", as shown in the photo.
The header must be completely flat and aligned with the PCB so clean up any joints that interfere with
this.
Ceramic and film capacitors
Install the capacitors on the TOP of the board. Solder and clip the leads.

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Bipolar Transistors
Separate the transistors on the workbench into NPN (2N3904) and PNP (2N3906). Install the transistors
on the TOP of the board. Do not mix up the NPNs with the PNPs. These are polarized components. Align
the outline with the outline on the board. They should be raised off the board surface slightly and at the
same height. Solder and clip the leads.
Trimmer resistors
Install on TOP so the adjustment is accessible from the back edge.
Electrolytic capacitors
Install on the TOP. Make sure you orient correctly. The longer lead and/or the lead marked with a +
needs to be inserted into the hole that has the “+” marking near it. Leads marked with “-“ go in the
board hole WITHOUT the “+”. Solder and clip the leads.
Potentiometers, slide switches
If the pots have positioning lugs on the front, cut these off with a sharp pair of flush cutting pliers.
Please ensure they are on the CORRECT SIDE OF THE BOARD before soldering otherwise PCB tracks and
pads may be damaged if they are desoldered. See Photo.
Lighted switch
Carefully insert the leads into the holes for the switch pins and LED pins. The plastic legs of the switch
must be flat onto the surface of the PCB. Any plastic legs which are fouled by other component pins
should be cut off so the switch can lie flat.

ER-808 – Assembly Guide
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ER-808 – Assembly Guide
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Testing
Install the ICs.
Plug the module into the Bus PCB.
Connect the L and R outputs of the Trigger/Output module to an amplifier or other listening device in
your rack.
Power on.
Press the button to light and then build a pattern of steps (see User Guide).
Start the sequence.
Adjust the BALANCE trimmer to place the sound in the stereo field.
Check the controls.