PacificStereo
07-07-2009, 03:42 PM
Well, this was fun. A couple of months ago, I scored a nice TC-FX77 at GW and decided to restore it.
For those that don't remember these, this was a silver TOL 2-head deck with Laser Amorphous heads, cool micro-touch controls, a nice FL meter and all the usual Sony AMS stuff.
After the overhaul, the deck came in at .03% W/F, which was a pretty remarkable result. But there was just one problem. While playback sounded good, there was some trouble in record due to head wear. This manifested itself as the "micro dropouts" that occur due to poor head-to-tape contact.
Well, I have ONE exact replacement head left, and one sub kit from Sony that requires a bunch of parts changes because it's not the same head. I really did not want to use either, since they are the last of the last. But since I had those to fall back on, I decided to lap the head and see what I got.
I used a piece of glass, and started with 600 grit wetordry paper (and water). I worked the head back and forth along the contour, very slowly and carefully. After I had taken all the visible wear out of the surface, I switched to 1500 grit to get the scratches from the 600 out. Last step was a polish with a compound that's equivalent to 10,000 grit paper (I don't have any of that fiber-optic polishing paper on hand). Nice and clean, and shiny, but not TOO shiny, as that makes tape prone to "sticktion." And a perfect tape-contact area. Nice!
The result? After reinstalling the head and doing a quick physical tape path alignment, it's perfect in both playback and record. Sweet! The best part is that those parts can stay in the bin.
For those that don't remember these, this was a silver TOL 2-head deck with Laser Amorphous heads, cool micro-touch controls, a nice FL meter and all the usual Sony AMS stuff.
After the overhaul, the deck came in at .03% W/F, which was a pretty remarkable result. But there was just one problem. While playback sounded good, there was some trouble in record due to head wear. This manifested itself as the "micro dropouts" that occur due to poor head-to-tape contact.
Well, I have ONE exact replacement head left, and one sub kit from Sony that requires a bunch of parts changes because it's not the same head. I really did not want to use either, since they are the last of the last. But since I had those to fall back on, I decided to lap the head and see what I got.
I used a piece of glass, and started with 600 grit wetordry paper (and water). I worked the head back and forth along the contour, very slowly and carefully. After I had taken all the visible wear out of the surface, I switched to 1500 grit to get the scratches from the 600 out. Last step was a polish with a compound that's equivalent to 10,000 grit paper (I don't have any of that fiber-optic polishing paper on hand). Nice and clean, and shiny, but not TOO shiny, as that makes tape prone to "sticktion." And a perfect tape-contact area. Nice!
The result? After reinstalling the head and doing a quick physical tape path alignment, it's perfect in both playback and record. Sweet! The best part is that those parts can stay in the bin.