Teac A-6300 R2R For Repair

SCompRacer

I snagged this pretty nice Teac A-6300 hours after it was posted. 10.5" reel capable. 1975-79 date manufacture. Heads in great condition. Great price. The original owner tried to fix it, failed and sold it. The first buyer tried to fix it and failed, sold it.

Video of issue below. FF to 25 seconds to see/hear issue. Right tension arm chatters in reverse play and the sound is distorted. It plays fine in FWD play.

The other neat thing, the original box with all packing and accessories/box were included. Both boxes needed some hot glue/carboard reinforcement. Sadly, they were careless stuffing the accessories box and cracked the oil bottle cap and some precious TZ-255 oil leaked out. Super/other glues would not work so I did the old thin gauge hook up wire wrap with a rat tail twist and dab of solder. Added a layer of epoxy over that. Doesn't leak now.

https://youtu.be/htdu9K0WCTM?si=bHXsxAzjXbPQlD02

Marketplace pic as I have it disassembled already.






Box is not in the best condition but better than nothing.

SCompRacer

Since I've been hanging out in R2R forums while fixing the 4010SU, I've picked up quite a bit of info on other Teac decks. The A-6300 arm oscillation is mostly caused by tape wear on the right tension arm guide pin. The tape drags causing the arm to chatter.

Fixes can be filing or sanding the entire guide surface (edges and flat surface) then polishing smooth. Since this arm was bent up so badly and the tape guide pin was loose, I opted for a new part. They had the arm and pin so bent out of shape it was forcing the tape out of the head guides in reverse play resulting in tape skewing off the head and distorted sound.

Ebay had some used arms, but they wanted new prices. Teac Tascam in Canada has some parts available for the old decks and they had a new arm for $33. The old arm doesn't look too bad as I had it out and peened the guide pin and straightened the arm. It sounded better in reverse play, but the arm still chattered a bit.




I have to remove the capstan flywheel for clean/service and new belt. Having this out of the way makes changing the arm easier.



The right tension arm is drooping. It connects to a cam that closes two micro switches when it is lifted with tape run around the guide. If the switches are open, nothing happens when you press play. The droop is from a broken plastic limit stop. The limit stop prevents damage to the micro switch nubs when the flat part of the cam contacts them. Force it down a bit by accident and you’ll need two micro switches.






I have a used limit stop on the way, but I have seen guys fabricate them. I had some 1/8” ABS here and it was within a few thousandths thickness of the broken piece. I wondered if the ABS might be a bit more resilient than 49-year-old plastic, so I made one. I couldn’t locate the broken piece, so I used pictures of a whole part as a guide and snuck up on the final dimension. It fits and does what it’s supposed to.



Those pencil lines will allow putting the pinch roller solenoid back where it was.



Good fitting snap ring pilers are a must to prevent this ring from becoming a Jesus clip.






I have more reassembly before I see if it fixes the problem. If it doesn’t, it could be reel motor torque out of spec which will be checked regardless.

SCompRacer

So duh...falling asleep last night it hit me the limit stop also stops the arm from moving too far to left in reverse play. Fully confident the fix is in. I just need the used part to finalize bottom shape.

Another issue was capstan end play seemed excessive. The capstan shaft was set too deep into flywheel. You can see marks from the hub in the stop bracket. The capstan has convex end to present smaller contact area.

SCompRacer

Got the used limit stop. I had already looked at videos of A-6300’s playing and filed the second stop on the fabricated one until the arm position clock position matched during play.

The flywheel had some oil inside the hub. I cleaned it and cut a narrow strip of felt and glued it in. Typically, you find foam or felt on capstan flywheels to catch any oil that may leak from bearing so it doesn’t get to the belt. The design of this one prevented a foam or felt disc around the capstan bearing hub area. The diameter of the bearing hub extends to the holes in flywheel.

Great results! Plays with no issues now in reverse. Good sounding deck. Now do I flip it and buy a better deck or totally recap it and keep it.

https://youtube.com/shorts/7aKpvWmfvF0?si=eFdJIivmjuYF-bzm






As an example, this is a capstan flywheel from the Teac 4010SU showing deteriorated foam replaced with felt. The 6300 used a rubber seal at the capstan end instead of foam like the 4010.

SCompRacer

OEM manuals scarce as hens' teeth so made one at FedEx Office. The OEM had an 11x17 and 17x22 foldout. Two schematics increased to 11x17.