Introduction
The analogue isolator pots on the Korg Volca sample are very fragile, they can break so easily.
The replacement part that you need is a 5-pin ALPS potentiometer which is impossible to find and purchase, or sold at very high prices (for a simple pot).
With this guide I will show a DIY solution to repair your filter pots on the device.
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The VS service manual is impossible to find, but it is well known that the two filter pots are 10K ALPS potentiometers
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By online search, you can find the KORG EM-1 service manual, which uses the same kind of pot for volume control
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The pot is VR2, an ALPS RK09K12C 5-pin potentiometer
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By searching on old ALPS datasheets, you can find the specs for the pot and the layout
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Looking at both the layout and the EM-1 schematic, we can see a shared ground (pin 1) and the remaining connections which form a dual wiper
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You will need a simple 10K stereo potentiometer with 6 pins
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The ALPS is a 103B, which is a linear one. I used a LOG one which works anyway (it will have a different sweep compared to a linear)
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You will have to bridge the two 1-1' pins together to have a shared ground
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The next step is to solder 5 cables to the pins (only one is needed in the shared ground)
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You'll have to follow the layout drawn in the image
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Solder the 5 wires and reassemble the VS, then check if the pot is working
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To reassemble the device, follow these instructions in reverse order.
