Is anyone familiar with the Sony TC-630 tape deck?


I have a friend that has one of these and says that the motor itself slows down after a few minutes. I do not physically have the machine yet. Not due to slipping belts or such.

Another acquaintance of his said that these machines are notorious for failures of their motor capacitors. At first I thought, sure, a PSC motor must have the cap. But looking at the schematic it seem to have a 1.5 mfd cap in parallel with the motor, and I would THINK that shouldn't matter.

Any ideas?

Yes, they do matter. Also, those motors need to be taken apart and cleaned/lubed

I intend to take the motor apart and clean/lube it. From what I've found, this is a 1969 model, and after 37 years I'm sure it could use it.

I've seen caps in parallel with motors, but they're generally a lot smaller (.01-.05), this one being 1.5 tells me it may be resonant with the motor?

The only other time I've seen large caps on a motor is for industrial use on polyphase motors, for power factor correction (and there they make a big difference). But he has heard from others that this particular cap is a common problem spot.

I think that you will find that there are 3 wires on that motor, and that the capacitor goes from one side of the line to an auxiliary winding of the motor, providing a phase shift for the hysteresis synchronous motor. That setup was common on Japanese tape recorders (Sony and Akai) of the era and on some German Record changers.

On models made for international use, there is usually a switch that will add additional capacitance for use on 50HZ.

That is what I would think...but the schematic shows it to be a 2-wire motor with the cap in parallel.

Sure, for a 3-wire motor (also known as a PSC - permanent split capacitor type) that cap is critical. I encounter this type of motor frequently. But if it is truly in parallel I don't see it as being critical. If it is truly in parallel I don't see it needing to be 1.5 mfd.

Guess I'll find out for sure when I get it in my hands.

I had a TC630 it's the one with only line output jacks. Replace the motor cap it's bad. Motor is a PSC type. Replace the cap with one of the same value as a cap of higher or lower value will affect motor speed

Huggy--
If you can't find that capacitor, just send a private message to me. I probably have it. The value is critical.

Another thing to watch out for is the rubber wheel that drives the capstan. When I had my TC-630 I had to adjust the spring for that rubber wheel as the large wheighted pulley on the capstan would start up rather slowly and wouldn't turn in 1 7/8 speed. Also I would recommend relubing all moving parts.

Hello Huggy,

Sorry to take so long to get back to you. I have been fishing in New Hampshire all week. (Sore thumb from lifting the smallies!)

I have worked on this specific model, the TC-630 as well as the TC-630D. The only difference is that the TC-630D has no line amplifier, it is a deck only.

In at least one half of the time, the motor capacitor is bad. I have been able to cannibalize caps out of other TC-630 decks to fix the problem. However, that is almost sure to only delay the failure to a future date. In all cases, the slowing motor was a bad motor capacitor. You may find a fan motor capacitor at the local electronics store if you are having a problem locating the proper value.

This machine has a couple of variations. One version is for export. It has the usual voltage switch to match your line voltage. It also has a capstan sleeve to increase the 50Hz speed to the same as 60Hz. Some variations have a capacitor that has two sections. So, you have to be sure you are replacing the cap with the proper value.

Another source of problem in most of these is the lubrication. The most critical place is the pivot for the pinch roller assembly. If this pivot is not free, the pinch roller will not raise and properly pinch the tape. This can cause the obvious speed fluctuations.

When properly cleaned and lubricated, this machine sounds very good with terrific high frequency response. It far exceeded the response of my AMPEX 961 that I had in the late 60s. The biggest problem is with the pressure pads. It causes a lot of wear on the heads but when the tape is pressed against the heads, it sounds great. I bought a TC-630 in Germany in 1970 and my cousin used it until last year. He still has a TC-630D in his studio.

I used to service these machines. Another problem in speed control is the brass bearing on the capstan itself. It wears out over the years, and the original is no longer available from Sony. I have 2 of these machines in excellent condition. One has been used less than 10 hours total. The other has years of weekly service under its belts, and it still runs fine.

Alot of times, I had to replace the capstan, also, as the shaft was worn at the sleeve bearing. Also, NLA from Sony. I just LOVE sony.

Bruce:

I was just using my old SONY TC 630 (great machine) after it sitting for a few years and the tape started slowing...then it stopped. Also...the pre amp green light went out.

Where can I get parts (I don't have a clue how to fix it) and who can fix it here in Ft. Worth Texas. Maybe that capacitor you talked about???

Richard

I've heard good things about this guy in Houston: http://www.angelfire.com/electronic2/vintagetx/ - but I've never dealt with him.

Thanks.

Wish someone knew some old guy like me in Ft. Worth or Dallas who can work on the TC 630.

Houston is a long way.

The standard failures on old Sony reel-to-reels are as follows:

(1) the amber-colored grease changes into bubble gum -- this especially affects bearings;
(2) rubber parts either harden or go gooey;
(3) motors get thirsty for oil;
(4) switches get touchy and controls get noisy;
(5) capacitors fail -- especially caps that sink higher currents or that get hot, usually due to proximity to a resistor or transistor that itself runs hot;
(6) pressure pads weaken and fall off;
(7) grooves wear into the heads.

Fred
repairing audio gear since 1972

Fred has hit on exactly the issues that these TC-630/630D machines have.

Two things that I might add:

I know that capacitors were mentioned. But the motor run capacitor is usually bad. It can explode (several did!) and spew wax all over stuff inside. Symptom is running slow.

When in good condition, they sound great, no Excellent.


I bought one in 1969 when they were new, brought it back to the US when I returned from Europe. My cousin used it in his studio until last year (after many, many reconditionings by me!) He literally wore it out. And he still has a TC-630D in its place. He has purchased about 10 of the various TC-630/630D on eBay and I have made good ones from parts.

I dont know if this is in the right place but here goes. I have a sony tc-630.The motor would not turn so i sent it in to get it redone.Got it back but same thing.I see that when i put all the belts on it slows the motor down.When you finally get it going the speed is to slow.Do i need new belts or rollers,wheels or what ever they are so the speed is correct.If i go to the lower speed it stops.If i go to the higher speed it's to fast.Love this old tape player and sure would like to get it going.Also when i go to rewind it just doesn't go.Where can i get any replacement parts if i need them? Thanks for your help

Two things come to mind. Lubrication of the capstan bearing and the motor run capacitor. Can the capstan be spun with your fingers? And if so, can you "stall" the motor easily or does it have good torque? I suspect the motor run cap...

Many of the belts that are sold as "Sony replacements" are too tight, and cause loading down precisely because they are too tight. Even though we knew better, we stupidly replaced a belt going to a Sony motor about two years ago. The belt was "tight" and we let it slide. Unfortunately, it killed the motor!!

Again, 3% - 5% stretch between the relaxed circumference of the belt and the circumference it stretches to when it's on all the pulleys.

Also, as Don mentioned, look closely at the lubrication, and check the motor run capacitors. These are very old, and they have a high failure rate.

Fred
repairing audio gear since the Pleistocene

Just a quick note to the owners:
<www.hifiengine.com> has a copy of the factory service manual.

Peter

CJ, this would get more exposure in the Classifieds section.