Hexagonal spanner for Fidelity Research FR 66S tonearm

Here is a photo. Have not been able to remove the black knob (I assume it is supposed to be removable and is part of the B60 VTA adjustment?) Before I take a large wrench to a part of an expensive mechanism that does not belong to me, I ask for further guidance.

Well I guess I also do not know how to import pics. Tried dragging and dropping twice but no luck!!

Black knob is NOT removable from the B60. You may damage the B60 if you try hard enough.

If you’re looking at the large round nut with flattened parallel facets, as shown in Elliot’s photo, I’d first try to turn it counterclockwise by hand, grabbing those facets. If that doesn’t work, then I’d use an adjustable wrench as I described above. Adjust it so it is in contact with those facets, hold it close to the head so you’re not exerting max leverage, and gently turn counterclockwise.