A quick update on the MDS-36 tape I ran tests on in February 2016. My initial findings were outstanding but there are a couple negative issues I have encountered. This tape is thin and seems thinner than a long play version of Ampex/Quantegy 400 series. Perhaps this is directly or indirectly connected to the most problematic issue I found.
After running the 7" test reel many times recording and re recording it, playing it, running it and switching it between decks I began to get the left channel loosing presence/volume. I noticed that if mild pressure was applied to the record head during recording that the signal became strong and even. The ends of the tape where it was run least were fine in all respects BTW. A careful inspection of the tape showed some edge waving and cupping which was leading to poor head contact. I don't know if it's the fault of the reel I used, the decks or the tape itself. However the decks run true and the tapes do not foul the reel flanges. So is this indicative of the tape structure itself? I don't know but other 1mil tapes have been fine on both machines. I also noticed when looking at the tape pack when the reel is fully wound that the surface appears rather uneven and wavy. This can be telegraphing imperfections in the reel hub and or from the leader and splice tape. But the unevenness is around the whole circumference. I have since spooled the the tape onto a known perfect reel at slow speed in order to get the tightest most even wind possible. That tape is stored tail out and will rest standing vertical for an extended period.
The other minor issue is the smudging from the black back coating that more than anything else the tape deposits. It hasn't been a problem just an observation. The oxide has remained perfectly intact.
I'm about to begin running the fresh second reel of MDS-36 with a known perfect reel and see how it fares. I am not convinced that the issues I found are the fault of the tape but more testing is needed.