Surprisingly, whoever did this did not swap the side rails to the newer style as well. Right now you have a mis-match.i saw this for sale and noticed the knobs are different compared to my 2505-2..are these in the foto wrong or did the knobs come in 2 different styles?View attachment 1085493
I think Mc is missing an opportunity by not reproducing those MC2205 knobs given all the MC2505/2105 in the wild...but of course I'm don't have the data to grind the numbers...
Am I missing something here? Has anyone checked Mcintosh parts lately to see if any of these newer OR older knobs are still available? Has anyone tried to "modernize" an MR77 lately? I repaired a damaged MC300 about five years ago (not my current one) and had to buy one knob. Gale told me then there were only two left in the bin. This style was from the newer C34V era. Shorter length. You see an occasional knob on ebay but they are random sizes from unknown models and sell for $25 and up each.The 2505 style (018-120) will fit the MR80 (and visa-versa). The MR80 type is the 108-160. These are also interchangeable with the MR7084 style (018-438). When it comes to the MR88 type (018-630) those are different - there is an offset that just doesn't work with the original style. So prior to the MR88 style, all are interchangeable.
Larry
As for me I switched to the newer style long ago. It took a while to get enough knobs. I couldn't find a large knob for my MR-77 at first so I just ran a bit of tape around the edge leaving about 1/8" of overhang around it. Then painted the knob black. From 8' away you couldn't tell it was not the right knob. Eventually I traded some old style knobs for that knob.
Reason I made the suggestion is the original MR77 tuning knob is very large and was only ever used on that unit. If looking to update the MR77 knobs, the MAC4100 tuning knob (also quite large, which again was only ever used on that MAC) would seem to be the ideal choice- assuming that it fits.