I have solved the problem that I had a pair of masterdubs that I bought recently that had been recorded with Ampex 468 - I believe. When the first (and only) time I played the tapes, they left some very nasty deposits all over my 1506. NOt very happy- cleaned it all up with the Lasermedia cleaner - not something I would want to do regularly. With my new recording Ampex ATR-700, I decided the best option was to bake the tapes and then dub them from the Technics to the Ampex. So I followed the directions from the internet (google "baking a tape") and bought an American Brands Necco Dehydrator (from Bed Bath and Beyond) Model FD-61 for $60 (minus the 20% off coupons from BBB). The internet article recommends model FD-50, but I think that is discontinued. FD-61 is cheaper and appears to be functionally the same. As per the internet directions I baked each tape for 2 hours at 135 F, turning over every 30 minutes. I did not have bananas or apples or beef jerky in the dehydrator at the same time. When I finished - after cooling the tape for 2 hours, I rewound it, using a small dry soft sponge (the little applicators that come with the Last Tape Preservative) to contact against the tape before it entered the machine. There were a few very small flakes of oxide that come off - nothing much - and the heads and guides were quite clean. I then made a dub, which sounds quite excellent (at 15 ips and 2 track). AFter the dub was complete and checked out, I discarded the original tape. I then repeated the process with the second reel. I only did one reel at a time in the dehydrator. The $50 investment looks like it has saved the music on the tapes and is supposed to make some really good beef jerky.
Larry