Multi-IO Expander Beta discussion

[XORadmin]

Though I cannot find in any documentation if Pull-up on multi-IO i2c-B should be set to 5 volt or ‘none’.

If the F8R doesn't have an own pullup (which you could probably check in its manual) then you need to use the pullup with the Multi-IO. In nearly all cases 3.3 Volt pullup should be fine.

The F8R doesn't have much of a manual, but the page does state:

I2C Header: 3 pin header to connect to other I2C devices in your rack, this is an unbuffered connection so cable lengths should be as short as possible (20cm/6" recommended).  There are 4.7k pull up resistors on this connection.

https://michigansynthworks.com/collectio...c-and-midi

... though there are no actual pullup jumpers on the F8R.

Pullup jumpers = pullup resistors.
The jumpers do make the connection to the resistors. So all fine. Start without the jumpers connected.