Try holding the IR controller DIRECTLY up to the IR sensor on the empeg (its directly right and above the knob on the right side -- I believe -- either way its on the right side). See if that works.

If it does, you have the same problem I had with my empeg mk2a - failed IR sensor. I had to ship it back to empeg to get it fixed, and when it came back it was fine.

Previously we had tried multiple controllers, and so on, no avail.

Give it a whirl.