Here’s some info that might be useful concerning which batches of Ampex 456 are good and which have sticky shed problems.
I recently unearthed 26 brand new 10 1/2-inch reels of 456 from 8 different batches. I checked one reel from each batch by playing them back and forth at 15ips (I only played the bad reels in one direction – that was enough!). The following batches were bad:
90297, 91049, 91055, 91079 and 91149
The following were fine:
94132, 94133, 94298 and 96190
The reels that were bad did not squeal during playback, but left debris on the heads and guides that was just barely sticky, so these are obviously in the beginning stages of deterioration.
All of these were Ampex (pre-Quantegy) tapes purchased in the early 1990s. Batch 96190 have lighter grey boxes as opposed to the textured, darker grey background found on the earlier batches, and the reel labels appear to be silk screened, rather than having sticker labels. None of these reels have the old rainbow-style logo.
I would guess that the good batches will probably remain OK – they’ve had a good 17 years to go bad and would probably have done so by now if there was a problem.
For whatever it’s worth…
Gary Galo
Audio Engineer
SUNY Potsdam
…speaking for himself