How a 1976, 1/4" tape head block should look

(full-scale: i.postimg.cc/CLFS6ZsP/20240401-160707.jpg )

Those great deals from either local Craigslist or the weekend flea market are all well-and-good...*but*: if the heads on a 48 year-old tape deck can't, at least, be restored to this type-of condition (here, off-of a Dokorder "model 1120" I'd found for only $25 back in 2018) --- the format will never sound as optimal as it is capable of being at its fullest potential.

I did those myself; using 800-grit wet/dry 3M sandpaper placed on a marble floor tile block and, by scoring the head the same number of passes across each side at a 45° angle.

When the worn part had been recontoured enough to a convex point (WITHOUT having a black line "crack" through the center of the playback head --- which, otherwise, would've meant the head was destroyed beyond usability): I applied Blue Magic metal polish cream spread across a microfiber cloth and, repeated the directional procedure like I'd done over the sandpaper (*until I got them into the condition they are in the photo attachment*).

I aligned them by recording the static from a FM tuner disconnected from its antenna while, adjusting for maximum treble output; then, I checked all the frequency responses by recording (at 7 1/2ips) test tones from a YouTube channel between 20Hz - 22,000Hz. They have enough life left to still be able to register the 19,000Hz FM stereo "birdie whistle" fine; however, the signal on the right channel starts to drop above that because there's a slight lamination split on the lower track of the play head (while the upper track does read to 22,000Hz).

Hell(?): this was a 10 1/2"-reel machine for $25! The biggest problem it had was the same issue all the old Teacs get: the grease on the pinch roller solenoid lever dried-out and got like paste. It doesn't sound as good as the Akai GX-365 I rebuilt (with 1%-tolerance parts in the preamplifier as well as with n.o.s. Nortronics heads installed), because it has early-generation NEC chips for the equalization circuit; nor, obviously, as good as the Magnecord 1024 I use as my main machine.

But, again, at THAT PRICE ($25): someone into these things can't go wrong finding the opportunity awaiting in such a deal.