Sony TC-K71 Debauchery

[ButchJames]

When I got the deck in May this year, it was completely broken, but the very first thing I did was to run my finger across the F&F heads. Not the slightest sign of wear!

I can't tell you how patient I've been with this machine, it was the only way forward, win or lose. In the end, I seem to have won!

I hope mr_rye89 wins too! ;o)

 

[vince666]

When I got the deck in May this year, it was completely broken, but the very first thing I did was to run my finger across the F&F heads. Not the slightest sign of wear!

I can't tell you how patient I've been with this machine, it was the only way forward, win or lose. In the end, I seem to have won!

I hope mr_rye89 wins too! ;o)

exactly! if there are some ferrite heads which can really be considered eternal, they are just these ones!
on top of this, their sound quality is just superb.
I have them fitted by Alex/A.N.T. into my modified Technics RS-B965MF and just love them.

 

[mr_rye89]

When I got the deck in May this year, it was completely broken, but the very first thing I did was to run my finger across the F&F heads. Not the slightest sign of wear!

I can't tell you how patient I've been with this machine, it was the only way forward, win or lose. In the end, I seem to have won!

I hope mr_rye89 wins too! ;o)

Almost! 90% there, brought back play, pause, ff, rew, This morning. Gotta figure out why the supply reel pinch roller is sitting to high and catching on the cassette shell.

 

[mr_rye89]

The ff/rew idler wasn't clutching, so I pulled this guy off checked the felt on the back, cleaned the nylon wheel behind it with alcohol and got ff/rew back, reel brakes work now too, the spring in the back was not in

 

[ButchJames]

I'm not sure what you know and don't know, but I'll put some input in anyway. ;o)

Apologies too, if I've misunderstood your problem, online comms is often full of mismatching of ideads etc.


Okay, so ... the supply pinch roller and its associated nut: the turning of the nut determines where the white guide (and roller) will 'sit'. To see the guide in action, you'll need a 'cut away' shell with tape inside, or a another test cassette that is transparent. This way you can see if the tape edges are catching the guide. During PLAY I simply lifted the guide up/down with my finger nail (not very technical I know!) and from which I could determine when the guide and tape 'cleared' each other.

BTW, and unless I've got this wrong, you may need to remove that plastic cassette loading tray - take care since the 4 screws are small; they can fly off at 100mph (a magnetic screw driver helps!) And there's a set of black plastic cassette shell 'guides' in there. Make note of which way they are seated before removing this.

 

[ButchJames]

 

[mr_rye89]

Yeah I'll take a look, I thought I might have bent something, but I'll probably pull that pinch roller arm off and double check. I think I have the loading tray put back correctly. I found a junk tape with a clear shell to notch out.......

 

[ButchJames]

I found when putting the supply pinch arm back, that I put it back incorrectly - it's easy to do this, and the gliding head assembly can be bent a bit if not careful when screwing in.

Look at the arm itself and see that when it's back in proper, it should clear everything - before PLAY and during PLAY. You can simulate PLAY by carefully pushing the base of the head assembly up and down. This pinch roller arm and head assembly should not be interferring with each other at all. The thing is - just be patient, and you should get there.

Plenty of 'WTF' moments for me as I eventually got it back properly.

 

[mr_rye89]

Found it. The JB Weld job was sloppy, not letting the head block fall back in it's resting position and causing the guides to hang up on the cassettes shell. I've also gone thru and replaced all the high ESR capacitors, and the low value electrolytics with Wima films.

 

[mr_rye89]

Aye she cleaned up Ok

 

[Bob Boyer]

Verrry nice...

 

[mr_rye89]

And it's finally off my bench! Next deck I wanna fix is the Marantz PMD-430. FF/REW don't stick (bent metal things) and the speed is wayyy off. I think I put new belts from Superscope in it in 2015.

 

[Bob Boyer]

And it's finally off my bench! Next deck I wanna fix is the Marantz PMD-430. FF/REW don't stick (bent metal things) and the speed is wayyy off. I think I put new belts from Superscope in it in 2015.

Had a 430 at one time. Nice deck if a little plastic-y. Good sound. Should have hung on to it as it had two speeds: it was modified to run at 3 3/4 ips in addition to the usual 1 7/8 ips. I bought two from the same lot from some guy who purchased surplus from police departments and court reporters. The second deck had been modded to run at 15/16 ips for interviews or dictation, I guess. It was definitely a parts machine, though.

 

[mr_rye89]

Got some hum on playback. may have to check the lead dress on the wires going to the heads......

Could also be filter hum, filter caps tested in spec but you never know......

 

[ButchJames]

I got 'hum' of a sort too, but shielding the LED display circuit board (returning a EMI shield that was there originally), and moving the Rec/PB cables around above the main board sorted the problem.

Press PLAY with no tape in, and see if it's PB noise first.

 

[mr_rye89]

I finally got to A/B with the Nak BX-300. Very very close. The Nak edges it out slightly in the high frequencies and has a lower noise floor. Still a nice deck though.

Any of you weirdos wanna do a Ferrichrome traveling tape?

 

[20tajk7]

Yes, a weird tape to record weird music

 

[ButchJames]

In my opinion, it's very difficult to be totally objective when comparing, subliminal preferences lean us towards one deck over the other.

A true 'human' comparison would require a true blind test were a third party operator would be doing the A/B switching, and the listener would then have to start guessing which is A, and which is B.

With headphones, I recall on a few occasions listening to a recording made from a good quality FM source, only later to realise I was not listening to FM, but the recording. I accidentally fooled myself.

Personally, I think one of cassette tape's biggest weaknesses is drop-outs.

 

[Elite-ist]

I finally got to A/B with the Nak BX-300. Very very close. The Nak edges it out slightly in the high frequencies and has a lower noise floor. Still a nice deck though.

Any of you weirdos wanna do a Ferrichrome traveling tape?

Sure - If you want to roll out a thread on a Type III TT project, I will join.

Nando.

 

[Elite-ist]

These old Sony decks are wonderful. I have a few of them. One of the rarities for Sony cassette decks is my TC-K80II.






Nando.