Restoring TEAC A3340S

[Bohuweno]

I have a shot at picking up a TEAC A3340S in good cosmetic shape at a lowish price. I can't examine the deck in person, and according to the information it doesn't play at the moment (I've looked up some possible causes so there are a few things I can try to start with). I've done some basic repairs on other decks including an A-series TEAC. I'm willing to go a bit further with repairs than I have done before, and might take on this TEAC as a potentially longterm project for that purpose. I also don't mind putting a bit of money into it, though the learning process - if needed to repair it - is a major part of why I am considering this deck. (Well, that and I like those old TEAC A-series machines.)

I don't know the deck, it's a four-channel recorder, so I have some questions. The 4-channel aspect is of very limited interest to me. I don't really intend to do anything with that, but the other features of the deck (7.5 and 15 ips record speed, 10.5 inch reels, and 4-track (1/4 track?) recording and playback) - thats what I'll be wanting it for.

The heads from the photo I saw were in good shape. But if I did need to replace them, is it possible to get replacements suitable for this particular deck? I know that relapping is also an option.

From the manual, I understand that 2 and 4 channel recording are both possible. Can I assume that there is no compromise in using this deck just for 2-channel recording and playback (I understand 2-channel in this context to mean 4-track/1/4 track stereo).

There are issues with some of the VU meters - possibly just lamps not working but not sure. Are VU meters often repairable without technician level knowledge, and can replacement lamps be found, or does that depend on the deck brand and model?

Is the belt different from an A4300? (I have a spare one). I assume it must be because of the compatibility with larger reels.

Appreciate any answers and advice. Thanks!

 

[oldvinyldude]

The heads from the photo I saw were in good shape. But if I did need to replace them, is it possible to get replacements suitable for this particular deck? I know that relapping is also an option.

Being a very popular deck, replacement heads are generally available. I suggest JRF Magnetics (no affiliation)

From the manual, I understand that 2 and 4 channel recording are both possible. Can I assume that there is no compromise in using this deck just for 2-channel recording and playback (I understand 2-channel in this context to mean 4-track/1/4 track stereo)

Sure-just put the track(s) into record mode that you wish, and record like any 1/4 track machine. You can even record one channel at a time.

There are issues with some of the VU meters - possibly just lamps not working but not sure. Are VU meters often repairable without technician level knowledge, and can replacement lamps be found, or does that depend on the deck brand and model?

Lamps are available. You may need to substitute a unit with axial leads-wrapping around the contacts. My X1000R had lamps out, and the specific ones with metal caps on the ends that went into the socket are no longer available.

If the VU meter is damaged, then no repair is possible. This is rare. Used ones can be found-Google is your friend.

Is the belt different from an A4300? (I have a spare one). I assume it must be because of the compatibility with larger reels.

Pretty sure it's different. I use the PRB cross reference chart. (no affiliation https://www.audiolabga.com/pdf/PRB_Belt_XRef.pdf). Once correct belt is determined, you can order from them, or through Teac USA-I believe they still sell belts-and would be a preferable source.

 

[Bohuweno]

Thanks for the replies. Very helpful information.

 

[Bohuweno]

I am probably getting this deck, and I now know that the playback issue involves two things: faulty rotation (too fast) and, if I understood the description correctly (not from a native English speaker), the heads don't engage. For rotation speed I already did a little research and from that got some ideas that I will look at first about what the problem might be (set to wrong mains frequency, belt in wrong location for the mains frequency, or belt not centred in the pulley). From the description, I suspect that the machine's belt is present and not disintegrated, but despite that, probably in need of immediate replacement.

On the other hand, I'm not sure what might prevent the heads from engaging (as I have no idea or way of knowing how the store attempted to test playback - but I think it was probably with a tape mounted). Does anyone have a suggestion about common reasons for that kind of problem? I'm just hoping to hit the ground running when I get hold of this machine, and want some things I can look for first.

 

[safebet]

On the other hand, I'm not sure what might prevent the heads from engaging (as I have no idea or way of knowing how the store attempted to test playback - but I think it was probably with a tape mounted). Does anyone have a suggestion about common reasons for that kind of problem?

I too love the A series machines and it sounds like you are familiar with their layout which varies only slightly over a range of models. The pinch roller pivot issue is very well known and easily remedied. Surprisingly capstan belts on these can last a long time!

I have 2340SX and 3340S 4 channel decks as well as a variety of others including 2 track and auto reversing models. Other than light bulbs and potentially leaky capacitors I suspect those switches require cleaning. My machines were selected based on overall condition with low head wear. To replace and align heads would easily cost several times more than I paid for any machines in my frequently used collection. By spreading out the use I anticipate they will out live me.

Always be cautious of any purchase but do enjoy the 3340S as a two channel unit if you decide to buy.

 

[Bohuweno]

I too love the A series machines and it sounds like you are familiar with their layout which varies only slightly over a range of models. The pinch roller pivot issue is very well known and easily remedied.

Well I hope that's the cause, because I did that particular procedure on my A4300 a couple of years ago. Thanks for the suggestion. I always check that pinch roller dropping action on old TEAC decks now.

 

[safebet]

The 4-channel aspect is of very limited interest to me.

It's worth mentioning that you can use tracks 1 and 4 for quite acceptable playback of native 2 track tapes.

I do live recordings of my band, two channels of the live stereo mix and two using suitably placed microphones. I mix to 2 track at home and then reuse the original 4 track master for the next gig.

Can I assume that there is no compromise in using this deck just for 2-channel recording and playback

No compromise at all!

 

[oldvinyldude]

I am probably getting this deck, and I now know that the playback issue involves two things: faulty rotation (too fast) and, if I understood the description correctly (not from a native English speaker), the heads don't engage. For rotation speed I already did a little research and from that got some ideas that I will look at first about what the problem might be (set to wrong mains frequency, belt in wrong location for the mains frequency, or belt not centred in the pulley). From the description, I suspect that the machine's belt is present and not disintegrated, but despite that, probably in need of immediate replacement.

On the other hand, I'm not sure what might prevent the heads from engaging (as I have no idea or way of knowing how the store attempted to test playback - but I think it was probably with a tape mounted). Does anyone have a suggestion about common reasons for that kind of problem? I'm just hoping to hit the ground running when I get hold of this machine, and want some things I can look for first.

If the pinch roller does not make firm contact with the capstan shaft, then the only thing driving the tape is the modest take up tension. This typically will be at a faster rate than the capstan mechanism driving tape. A seller can say yes, it plays back, but they can leave out the fact that it is playing too fast.

As a test, load tape, put in play mode and push the pinch roller up against the capstan shaft. If normal playback speed results, then it’s time to clean and relube.

Unless I missed something in what has been stated here, your deck needs a thorough cleaning of old lubricant by partial disassembly of the drive components, liberal use of alcohol and swabs to get any areas that slide or rotate. Light machine oil for bearings-a drop is all you need there. A high quality synthetic grease for sliding things. Apply carefully, modest amounts are all you need.

 

[Bohuweno]

Thank you gents for the additional information. That's also going to be of great help to me.

I'll be getting the deck in about 5 days, and it'll probably be a few days more before I unpack it and check it over. Although I've bought three unseen decks before and had good luck, there was a slight extra element of a gamble about this one. Nothing dramatic, so if it's a dud after all and I'm not too downcast, I'll explain that later. I'm hoping that it's in about the condition of the other three decks I've bought, which is to say in decent shape and able to be brought back to full working order with a little work and a little money.

 

[Bohuweno]

I received my deck a week ago. Visually it's in excellent shape - better than I've seen for any deck of this age (according to production history it should be 1978 or earlier). It looks to have been lightly used, there's no wear on any part of it, and nothing got scuffed.


After adjusting switch and belt to 50 Hz, and cleaning and demagnetizing the heads, and thoroughly cleaning the roller, I tried some tape in it (10.5" reels). After 15 or 20 minutes or so, it slows right down.

I ordered a new belt, installed that, and carefully cleaned and relubricated the following: capstan assembly, pinch roller lift arm pivot section, and pinch roller shaft. The pinch roller lifts and drops cleanly now. As far as I can tell, the roller itself doesn't need to be replaced.

The right tension arm lifts and drops cleanly and fast. The left when held down moves back up, taking perhaps a little less than a second. It doesn't go all the way to the extent of travel, but stops around 1 cm short. I can push it to the end with a finger. I'm going to disassemble and lubricate this part.

I was looking for a solution to the tape slowing down. One suggestion seems to be replacing the (capstan) motor capacitor. My service manual PDF lacks exploded diagrams and schematics for some reason, but I have the service manual for "A3300/A3340". The schematic info for this capacitor is "2+0.8/250V". The can on my capacitor is printed with "0.8uF" and (sic) "250WV.AC". It's a dual capacitor (3 legs) and the underside of the circuit board has one leg marked 0.8 and the other marked 2. So that all seems to match up. However, it looks like it would not be at all easy to get a direct replacement for it. I'm well into new territory here. Some people suggest using two capacitors as replacements, strapping one to the side of the other I think, and wiring in as appropriate. I'm up for that, just not sure about the details of how to go about it. If anyone's done this, tell me more...

I'll also get to disassembling and cleaning the capstan motor. Not something I've done before, but I also have a Pioneer turntable that may need to have its motor cleaned, so now's the time to learn.

 

[safebet]

Happy to hear that the deck arrived in good condition. If memory serves, the 0.8uF capacitor is there to optimize performance between 50 and 60 Hz operation; the belt pulley of course sets the correct speed.

It is odd that the synchronous motor runs and then slows down. If the motor is properly lubricated I would be cautious to continue until the capacitors are replaced. Someone else might have direct experience.

I say this because the capstan should have final control over tape speed. My assumption is the reel torque resistors are switching in and out correctly. The reel motors always run the same direction with weak torque (to maintain tension) and only engage with full torque one side or the other for fast wind operation.

 

[Bohuweno]

I couldn't say for certain whether the capstan motor is properly lubricated. It's simply as it was when I received the deck. I've added some oil through the top tube without waiting for the level to stop dropping, but don't yet want to put in more than I have done. In any case I've made a bigger problem for myself that's going to throw in a big delay: I took apart the left tension arm and cleaned and relubricated it, but lost the spring inside the deck when I was trying to get it back onto the arm. It hasn't dropped to the bottom of the case - and I lost it while the case was laid face down (on a soft surface), so I think it's going to take some major disassembly to find out where it went. I won't even be able to set aside the time that's going to take for a week or three. And I _really_ don't like disassembling more than I have to, but it's the only way I'm going to find this damn thing.

 

[Hot Sauce]

Hey there,

I have a 3340S that I restored last year. It's a really fantastic deck - only thing missing is varispeed!

I got kind of lucky though, and the only mechanical issue I had to deal with was frozen pinch roller/lifter mechanism, and dialing in the backtension and brake force with a spring scale.

For lubricating the motor, there's actually two tubes. One of them is hidden right near a large can capacitor near the motor. It's on the same axis as the easy-to-see tube, just further back. A bit of digging through that bundle of wires and you should find it. I'd follow the service manual procedure for that - usually the amount of oil you're supposed to use is a lot less than you'd think. And yes, the 3 leg capacitor is for allowing both 50 and 60Hz mains operation. One thing you can do is just replace each part of the capacitor separately, pretty fool proof. You replace the 2uF section with a 2uF cap, and .8uF section with a .8uF cap. Probably cheaper than getting a special value 3 lead motor cap, though they can be found. I haven't ever done this, but from what I understand usually there's a switch between 50 and 60Hz operation that switches in or out the extra .8uF part of the cap. I don't recall which value is for 50 and which is for 60, but if you're 100% sure you'll only use it for 50Hz and you find out whether 50Hz is operating with 2uF or 2.8uF, you could always just replace it with a single value, but you'd have to be sure the leads are going to the appropriate place. That's where the schematic is very useful. I actually have a copy of the tape transport schematic right here.

One thing you need to be aware of is that not only is the capstan motor an AC motor, but the reel motors are as well. So not only does the capstan motor use a dual value run capacitor, but both reel motors do as well. The values for the reel motors are 5.3uF + .7uF. If you replace the caps for the capstan motor it may be a good idea to do the reel motors too. But your slow speed problem is likely not caused by reel motors, since if the takeup was running slow there would be excess tape at the takeup side which would cause the right tension arm to drop and the deck would automatically stop.

Sorry to hear about the spring... and yeah you really do wanna find it before turning the thing on again, lest you accidentally short something to something else in a destructive way. I'd imagine it may be sitting on top of the audio boards for channels 1 and 3 (I believe 1 and 3 are the top boards). Not sure if you already know this, but if you lay the deck on its side you can swing out the bottom two audio boards - they're on a hinge. If you remove the feet on the bottom, the panel that wraps around the bottom of the deck and part of the back can be easily removed - that and the wooden side panels should be removed (they're easy/simple to put back on). I'd think this would enable you to find where the spring went, assuming it didn't lodge itself somewhere totally stupid.

 

[Bohuweno]

Thanks mate, a lot of great information there, which I'll certainly be drawing on when I can get back to this deck.

I did see another of those large can capacitors, was wondering which motor it was associated with but had other things on my mind at the time. Your suggestions could be very helpful locating that spring - I know I'll have to find it because of the shorting issue or other things that don't bear thinking about. It's my own fault, and partly a result of pushing ahead while tired. I'll take it as a learning opportunity for getting to know the internals of the deck better.

 

[D_Zoot]

I took apart the left tension arm and cleaned and relubricated it

The tension arm on the left side of the unit as you look at it, or the LH arm from the perspective of the deck itself? The arm on the LH side of the deck as you view it (the supply reel side) was lubricated with a silicone dampening oil to intentionally slow the operation of the arm. Without some manner of dampening you'll get tape bounce when engaging play and it will also bounce during a fast wind adding to uneven tape spooling. If that's the arm that was apart, consider sourcing some 300,000CST silicon oil and reapplying it to the arm before buttoning it all back up. If it was the arm on the take-up side, ignore me, that one was is supposed to operate freely.

 

[Bohuweno]

Left as viewed from the front of the deck. I'll get hold of some of that silicone oil then. Thanks for the heads up.

 

[Hot Sauce]

FYI, it's clearer to refer to the tension arms as either "supply side" or "takeup side." Simple and effective.

 

[Bohuweno]

FYI, it's clearer to refer to the tension arms as either "supply side" or "takeup side." Simple and effective.

For this model, sure, but two other decks in my possession are auto reverse. And the service manual for this model does actually say "left" and "right" for the tensions arms. Seems logical - I've generally gone with the idea that left and right in audio would be from the viewpoint of the listener. Anyway, I'll follow your suggestion.

 

[Hot Sauce]

Ahh sure I could see how bringing autoreverse into the question would complicate it. I guess in that case I don't usually think about the reverse side - from the "perspective" of side A, so to speak

Sorry if I came off a little short there !

 

[Bohuweno]

Sorry if I came off a little short there !

The thought never occurred to me.

@D_Zoot

If that's the arm that was apart, consider sourcing some 300,000CST silicon oil

Concerning this spec., is there any leeway on that? I can get Kyosho or Tamiya in just about any value except 300000 at the moment. Not sure when 300000 will be available again, although when it is, it looks like I can order direct their websites.

I also have some leftover Traxxas Diff lube 500K that I bought for damping a tonearm.