Sem Sub Osc Module (1974 - 1979)

Name: Sem Sub Osc Module (1974 - 1979)
Brand: Min butik
Price: 600.00 SEK
Availability: InStock

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Product description

SUB OSCILLATOR
FOR THE OBERHEIM
SEM MODULE

Non destructive, fully reversible and requires only one soldering point

This Sub Oscillator add on to the classic Oberheim SEM makes use of the very often unused EXT IN #1 and #2 knob. With this non destructive, fully reversible mod you will get two octaves of Sub Oscillator controlled by the EXT-knob of your SEM Module. Turn the knob to the left (#1) and you will set the level for a square wave Sub Oscillator of -1 octave. Turn the knob to the right (#2) and you will set the level for a square wave Sub Oscillator of -2 octaves.

This mod uses the already installed Molex connectors underneath the SEM circuit board, so it only requires one (1) soldering point for the +15V supply. The other connections are already there, ready to be plugged in.

If you want to keep the EXT IN as it is, that’s no problem. Then you connect this board in only one of the two connectors (closest to the edge) and you will have EXT IN when you turn the EXT-knob to the left (#1) and a Sub Oscillator of -1 octave of you turn the knob to the right (#2) - but then you miss the -2 octave option.

This mod really takes one of the best synths in the world to the next level

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How do you install it?

Follow the steps below to ensure a smooth and successful installation

Step 1

Remove the 4 screws

Step 2

Fold open the front panel. Be careful not to harm any of the long potentiometers on the front. The connectors we will use are A, L, M

Step 3

Attach the two connectors of the sub circuit board to the two connectors on the SEM circuit board

Step 4

Attach the connector labeled "A" to the Molex contact "A"

Step 5

Solder the red wire to the tip of the large capacitor (+15V), or to the large surface connected to it

Step 6

If you want to keep the AUD IN-option, simply attach the board in the connector closest to the edge. Now you will have AUD IN on EXT#1 and SUB -1OCT on EXT#2

Step 7

For safety measures: Secure the AUD IN cable to the bottom of the SEM with duct tape, so it doesn’t come in contact with the power supply

Important notice when using two or more in one unit