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  #1  
Old 10-26-2016, 10:16 AM
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TEAC A-6300 newbie - low record level and subdued highs

Hello,

I'm new to reel to reel recording and I'm just trying to slowly learn about things.

I've got a TEAC A-6300, which looks wonderful cosmetically, but has a perfomance issues -- specifically, a generally low level, and a lack of highs (more detail later).

I have some experience with tinkering with electronics and mechanical things (and instruments), but I'm not an expert.

From reading threads here I've picked up on some ideas and possibilities, but I wanted to kind of gather those things and see if this is a good direction to go. (If there is already a thread like this, I apologize. I looked, but did not run across it.)

More on the problem: I noticed it when recording off an LP and toggling the MONITOR switch between the tape and the source. The tape was missing a lot of the highs, and the level was generally lower (about 3db, I think).

This could obviously be coming from the Record head or the Play head, but I don't have a good commercial release tape for testing. I'm working on getting one.

I have however, demagnetized the heads (and capstan, etc), and cleaned them with alcohol and a q-tip. This seems to not have made little difference.

1. Should I take it to a repair shop (there is a good one in town) for a head reallignment? Is that the most likely issue?

2. I read (here) about people using 2000 grit sandpaper on the heads, then alcohol to really get them clean. This seems scary to me. Is that really a good idea, or just someone posting a bad one? (The heads look clean, but I reckon looks can be deceiving.)

3. I read of cleaning the capstan with something like Scotchbrite. Good idea? If not, what is good.

4. Is Tech-spray Rubber Rejuvinator a good thing to use on the pinch roller? (It's not gummy, but it has some brownish/greyish residue; from tape I assume.)

5. I've seen this mentioned, but haven't read much about it, but since this thing is decades old, would it be a good idea to go through and replace all of the capacitors?

(Is there something I should check that I haven't mentioned?)

Another dumb newbie question. How much difference does tape make? Could this be just becuase I'm using random old tape? (I've got some new tape, but don't want to load it until the machine is really ready to go.) This seems like too big of a difference to be due to crappy tape, but I guess I don't actaully know that.

Thanks in advance for any answers. I love this thing and hope to use it to be recording music soon and while it doesn't sound bad, I want to make sure it's at it's best before I start using it.

Sorry for such a general post. I tried to find good info on this, but have only seen passing references in other posts.

Thanks again,

Luke
  #2  
Old 10-26-2016, 03:27 PM
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Jonny Ramone Jonny Ramone is offline
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You'll have to try with a new tape to make sure. Check to see if there are flat spots on the crown of your heads, as if they are too worn, they will give poor performance. There are some new tapes available in addition to RMGI LP35, which is a good tape to try on it.
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  #3  
Old 10-26-2016, 03:36 PM
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Heads could still be dirty. Post a close-up, in-focus photo of the heads. Sometimes you need acetone to fully clean heads and guides.

Never use sandpaper or Scotchbright on heads or capstans.

Never "align" the heads as a "guess". If they have the original factory alignment and the lockpaint on the head screws is undisturbed, then no one should touch head alignment.

Use new tape for testing. Recommend SM911.

Also, the problem could be that someone messed with the internal calibrations. If so, it just needs re-adjustment by a technician.
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  #4  
Old 10-27-2016, 08:19 AM
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Okay, I will try acetone. There was some stuff on the capstan and tape guides that just didn't want to come off with 70% rubbing alcohol.

I will also try a new tape. I have quite a few NOS shrink-wrapped tapes.

Here is the best photo I could get of the heads. If this isn't good enough, let me know and I will borrow a more professional camera.





Looking at these, it certainly seems they need more cleaning. They looked okay with the naked eye, but I now see I need to put more elbow grease into it.

Also, when I mentioned alignment, I was going to take it to a reputable shop here in town (Austin, TX). I just want to make sure that's necessary before spending scarce resources on it.

Thanks again for the help.
  #5  
Old 10-27-2016, 08:22 AM
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A couple of other questions:

I've seen the idea of using a head demagnatizer covered with a q-tip for head cleaning. (I suppose the idea is to dislodge anything magnetically held to the head? Is this a good idea? (My thought was that if the head was demagnetized, nothing should be magnetically held to it anyway, so it seemed unnecessary, but maybe I'm not thinking of it properly.)

Also, is it a good idea to oil the motors? There's nothing that shows me they're not working well, but wasn't sure if this was something that's a good idea as regular/preventative maintenance, or should only be done in response to a problem.

Thanks,

Luke
  #6  
Old 10-27-2016, 10:33 AM
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Yes, the heads, guides still have tape residue. Clean heads/guides/capstan with acetone for this one time. Don't use acetone for a daily head cleaner. You also may need to use a mild polish compound like NuFinish. Stains on the capstan are ok and don't effect anything.

Even a repair shop may mistakenly try to re-align the heads. Don't let them do that if the heads still have the original factory alignments.

Again. No sandpaper or Scotchbright!
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  #7  
Old 10-27-2016, 02:22 PM
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I have 2 A6300's. Remove the 2 screws on top of the head cover and remove the cover to expose the heads and guides. lay the deck on its back and clean with denatured alcohol. I use small pieces clean white paper towels with alcohol on them to clean the heads. wipe them lightly and gently until clean. I use Q-tips on all the guides. Stand the deck back up and put the head cover back on. Send the pinch roller to Terrry for new rubber because the old one will eventually turn to a heep of goo.
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File Type: jpg Tascam Teac A6300 x 2 b.jpg (46.6 KB, 16 views)
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  #8  
Old 12-05-2016, 08:34 PM
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Okay, so an update.

I re-cleaned all of the heads.

I also recorded onto NOS Maxell UD-35 tape and with the proper EQ and Bias settings, things sounded great when toggling the source and tape switch. SUCCESS!

(By the way, to answer an earlier question, it appears the head alignment has never been altered.)

Now I face another question/problem. A user above suggested trying it with commercial pre-recorded tape as a test. This weekend I ran across Magical Mystery Tour on reel, and quickly snapped it up.

I excitedly put it on, only to find the the Right channel has a much lower level (actually close to non-existant). It is the right channel though -- the audio is different, so it's not that it's picking up crosstalk from the next channel. When I crank that side, I can hear the vocal that's not present in the other side. At least this is a positive for the wild stereo mixes of that era. So it's picking up the proper track, just at almost no volume.

When playing Side 2 (by using the left-facing play button), the same thing occurs. It's very consistent across the whole tape.

Now, the possibility that there's something with my deck that makes it play back things recorded by it perfectly, but not tape recorded properly has me worried. (This worry is increased by the fact that I get the exact same result playing Sides 1 and 2 of the commercial tape.)

I realize the best way to test it is with a "known good" tape, but what's a good source for this? I'm looking at another reel on eBay, but who knows what that will be like.

I guess my other question is, is it typical for a commercial tape like this to have problems over time? I also just thought this might sound familiar to someone with experience.

Any insight is greatly appreciated. I feel as though I'm in a bit of a spot because I'd like to return the tape if it's bad (and I should do that quickly if that's the case), but I also would hate to return the tape telling the shop proprietor it's bad, when the problem is actually with my deck. Like I said, any help is appreciated.

Thanks
  #9  
Old 12-05-2016, 10:30 PM
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I sold all my pre recorded tapes as I could get way better sound recording to a good Maxell or preferably one of the new tapes out now. Yes some of them recorded at 7.5 ips can be good but all mine were dull with age. If you are recording and playing back successfully it could be your Beatles tape at fault.
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  #10  
Old 12-06-2016, 12:22 AM
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The deck could have dirty switches in it and should be cleaned with Deoxit as obtained from MCM when it is on sale.
The heads look very good to me. The testing of the machines level need to be done when the output control is at specified output level otherwise the meters are not showing the true print level. I work on these decks all the time and the deck you have is going to need some work if it has not been restored already. Factory aligned heads do not mean they are perfect. I often times get them to be better. You need an expert to work on the deck not just some shop as they will miss a lot of stuff that they don't even know about. In fact they could learn a lot from posts right here but are probably too arrogant to read such stuff. If a shop is good in an area or even an individual I will usually know about them
Other than Rolf Ohlsen at Vintage Tx I don't know of any good shops in TX.
If you want to keep the machine and want it working to specs or better then send it to a proper Technician who can get the best out of it that it can be. It will need some new grease in it as well as better oil as well as some oil in it, often times the record EQ caps are changed to bring it in line with today's better tapes and on occasion they need a new motor pulley as the motor can be slowing down. The speed EQ switch needs to e cleaned. Pre-recorded tape are NOT alignment tape and so you can not believe them or should you use them for precision adjustment. Some machines need cards to be recapped as they lose gain due to decayed or low grade condition capacitors. I commonly recap the power supply to start.

Just to let you know those heads are just past them being broken in so you have about 98% of life left in them.
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Last edited by Skywavebe; 12-06-2016 at 12:24 AM.
  #11  
Old 12-06-2016, 02:40 AM
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I must admit, head wear is still a mystery to me. Photography has to be just right for (static) visual evaluation - reflections can be misleading. But for Sam to say that these heads are in such great condition - not just OK, but 98% remaining life - just made me think "What do I know".

Must have been music to Luke's ears. How did you get such good photos without a "professional" camera? Focus, proximity & lighting were much better than a lot of shots that we see.
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  #12  
Old 12-06-2016, 06:56 AM
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The pictures have to be taken with a person who knows the photography of macro shots and that has an appropriate camera. I use a digital Nikon which has a 18" limit so some shots are cropped and zoomed according to what I want to show.
I think there have been plenty of pictures of worn heads here before so a person who has been reading post for a while should have a little understanding of what to look for. Here are some good, bad heads-
Attached Images
File Type: jpg Worn head stack sm.jpg (51.7 KB, 32 views)
File Type: jpg New P R heads 4trk sm.jpg (364.6 KB, 34 views)
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  #13  
Old 12-06-2016, 08:17 AM
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Thanks for all the great information.

Yeah, I feel like I got super lucky with this deck. Cosmetically, it's in museum like shape. It came with the dust cover which is free of the minor scratches these things are usually full of. (It does have one small crack on the side, but it has no effect structurally.) I also got the unused remote, as well a box of 10 sealed Maxell UD35-90 tapes. All for $320.

Have you heard of Switched On in Austin? I've had great experiences with the place, but I can't independently verify anything about the quality of the service. I'm curious if people here are familiar with them, but wouldn't recommend them. (Their local reputation is good, but they are also the one place in town everyone knows, so they're not usually critically compared with others.)

Quote:
The deck could have dirty switches in it and should be cleaned with Deoxit
I can (should!) do this, but was impressed with the lack of static, etc, when turning any of the knobs or switches. Still, it's surely a good idea. Is it best to disassemble the thing, or just mask it well and spray deoxit into the switches through the panel?

Quote:
It will need some new grease in it as well as better oil as well as some oil in it
This seems like something I should be able to do. I will look for posts here to see if I can get some guidance. (I'm trying to avoid having to take in somewhere, just because I don't have the spare cash, but would really like to start some projects with this thing soon.)

Quote:
Some machines need cards to be recapped as they lose gain due to decayed or low grade condition capacitors. I commonly recap the power supply to start.
I may go ahead and do the power supply. Sorry if this is a dumb question, but what do you mean by "cards"? I'll see if I can get a service manual to look at the EQ capacitors. From what you said though, it sounds like you meant not just replaced, but actually changing the values, which I'd have to learn quite a bit about first. (I'm just smart enough to solder in new capacitors, but still learning to be able to decipher anything but simple schematics and actually understand what's going on and why.)

Quote:
Just to let you know those heads are just past them being broken in so you have about 98% of life left in them.
This is great. I am hoping to use this deck for semi-serious recording, so I do want it to be at it's best and hoping to use it for a good long time.

Quote:
How did you get such good photos without a "professional" camera? Focus, proximity & lighting were much better than a lot of shots that we see.
Ha! My wife is a professional photographer. She took them with her iPhone, but she used a bounce card to balance light, and did some manual exposure. It just goes to show that the craftsman is more important than the tool, I guess.

Thank so much everyone. This board is great. Once I get this recording going, I'll be sure to post it.

Luke
  #14  
Old 12-06-2016, 02:41 PM
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Quote:
Originally Posted by Skywavebe
I commonly recap the power supply to start.
Okay, so I was looking into this and have a question. Do you typically replace the "snubber" or "spark killer" (as TEAC says in the service manual)? I've heard that these "snubber" components are typically fine (typically meaning: general equipment, not R2R specific).

EDIT: I just realized I was looking at the wrong page (A-6100) and this one has 23 (!) of these "spark killers" and they are in fact a great majority of the capacitors on the power supply. I'm now guessing that you do replace them. (Any leads on what to use would be appreciated. What I've been finding is unaffordable when replacing 23 of them.)

I think I'm going to go ahead and do the power supply. (I had an Apple IIe let it's smoke out somewhat recently due to a power supply cap, so now I think recapping power supplies is good general practice. )

Let me know if you can about the oil, and if there are any other caps you'd recommend while I'm at it.

Thanks so much. This board is great.

Luke

Last edited by TEACLuke; 12-06-2016 at 02:57 PM.
  #15  
Old 12-06-2016, 06:07 PM
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My advice for getting a nice mirror finish on those heads is using Noxon 7. I use this polish on all my heads once a year, and they look brand-new. I usually apply the polish with a Q-Tip using a back and forth motion. Then let it try, and wipe clean with a fresh Q-Tip. For extra dirty heads a second coat may be needed. Based on what I see in your photos one coat of Noxon 7 would do wonders. It also helps by creating a nice smooth surface for the tape to glide over. I am including a photo here to show you what the product looks like. I swear by this product as I know others here do as well.
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File Type: jpg 062338001173.jpg (51.1 KB, 9 views)
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  #16  
Old 12-06-2016, 08:07 PM
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OK,
Oiling. There are tubes once you take the back of the deck off on the central AC motor. This motor has a fan on it that I typically take off and clean with dish soap and a old tooth brush in hot water. There are two Allen screws that fix it to the shaft in front of the fan. The two tubes are at each end of the motor. About 10 drop of oil would help a lot. The oil I fnd that works best I AMS Signature Synthetic oil which I happen to have left over and it was 10W30. This oil needs to also be placed into the capstan bearing. This will be a thing to do when you deal with the pinch roller linkage. IF there are oil tubes on the reel motors they are front and back as well. IF there ar no tubes visible then the unit has ball bearing it it.
The Captan belt needs to be changed I would say at this point. It may still be in 0ne piece but it could be stretched or glazed. i take the motor out when I deal with the restoration and oil the bearings down each shaft which is a faster way to get oil into the bearings and at that time I clean the motor pulley of any residue.

The Spark killers or RC type packages do hardly fail in these decks. I can not remember any to any great numbers in 40 years. I did have one blow in a DX-8 dBx unit. I put a Spark Killer unit that I bought for Revox decks where they blow all the time. This is called a Rifa cap but also is new and should not give trouble. I don't think that will be needed to change those.
Now the caps you do change are called Electrolytics. The cap kits I change for the A6300 when purchased from Mouser is about $8.00
A6300 Power supply cap kit
1000uFd 35V $1.00
330uFd 50V X 3 $3.90
470uFd 50V $1.80
100ufd 35V X 2 $0.90
Total $7.60

You can certainly change them all over the place if you want but that can take a god day with a person who does not move like a Technician does. The 1000uFd caps I change with 1500uFd same voltage types.
This is not costly at all and just make sure you put them in the right way. If the deck has a lot of Axial types then you can put Radial typoes in their place. I just allow them to stand up with leads spread out to the sides. here is usually a lot fo room as they are smaller in size than the old Technology.
Brake pad are often not looked at. If they are not white and fluffy I would change the pads.

A lot of this work that I am talking about may be over your head and why it is better to just have a Tech do it. Even if you get all the mechanical stuff done the alignment tape and scopes and meter are not something you would have on hand unless you were a Technician and this would not be post these questions. Most people do not know of the extensive level that we go to to make these things sing well.

If the Pinch roller is hard or has divots then send it to Terry in a week or two in advance of when you are working on it. The capstan shaft if glazed needs to be treated with sandpaper to give it the matt finish. This is not a scratching but a imprinting done as a pinch roller is wrapped with sand paper by way of double sided tape. The the roller is allowed to play on the machine for about 10 minutes.

The A6300 has a critical right tension arm. The reason why I say that is that it determines the tape path as the deck goes in the reverse direction. If this arm is bent in or cocked,the tape will not travel straight through the tape path and the high and then levels can be lost. It takes me 2 hours to place one in a perfect position so that the phase and levels are close in both directions.
Some of my trainees can be amazed in how much detail there is required to get these decks right and sometimes modification.

Record EQ changing- This is done to cut the level of boost at 7.5KHz in the record circuit to help tapes like Scotch 203 sound good. LPR35 is much better tape than 203 just as 406/407 or Scotch 207 was. This tape does not require the boost so the change we often make to the high speed record EQ is from a Mylar (green) cap labeled 153 to a Mylar that is a 103K. The 103 means .01uFd at 50 V. These can be had in quantity at about $.06 each. If you need some- you most likely only need two, I can send you some in the mail. I just got 200 in for stock.
If you don't have Mylar Polyester caps will do and even polystyrene if on hand. I could write a book but lets not do that. I am long winded enough the way it is.
Send me an E mail with with address.
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  #17  
Old 12-07-2016, 02:19 AM
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Quote:
Originally Posted by Skywavebe View Post

[snip] I think there have been plenty of pictures of worn heads here before so a person who has been reading post for a while should have a little understanding of what to look for. Here are some good, bad heads-
I can recognise the good & bad (centre head) examples. With the "bad" heads I assume the broad vertical band at the centre of the head has been worn flat by extensive use. I'm often confused whether this is a reflection caused by the curvature of the heads. Seeing the head live (so to speak) must allow you to scan it from all angles & give a more accurate assessment.

Can the continuity of the black lines provide clues?

Thanks in advance for you input Sam. Not sure where we'd be without you & your contempories.
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  #18  
Old 12-07-2016, 06:28 AM
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Lance Lawson Lance Lawson is offline
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Sounds like the deck is actually in good shape just needing cleaning and lubrication. If the better tapes you recorded sounded good after your more through cleaning then that helps confirm the deck is sound. However pre recorded tapes like the Beatles tape you bought are totally unreliable. Even if the tape is still sealed it could have suffered from poor storage or magnetic damage. Old blank tapes are hit or miss and used tapes are virtually useless for testing except for transport operation. Also as someone new to this medium you will do well to avoid tapes made before 1970. Tapes of the 50's and 60's are not only sonically inferior to later tapes but the oxide coatings are considerably more abrasive than later tapes. The current tapes in production are all good and all have a much smoother oxide coating which means less head wear.
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  #19  
Old 12-07-2016, 07:22 AM
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Wear marks-
Think of the surface of the head as a parabola. In this curved area is a cut going downward which is the gap which is between the two pole pieces.
This gap starts out close together and with a depth that is the gap length.
When heads seem 1000 hours of use then the tape wears the surface of the head down. This wearing down first starts out as a abrasion and then continues more to a very small flat spot that only happen where the tape rides. As time progresses the wear mark as measured now side to side in the direction of the tape gets wider. Technician come to know this as a degree of wear indicator. Ferrite and glass heads do not wear this way.
Now perhaps at 2000 to 3000 hours the width of the wear mark is getting wider and will eventually hit 3 mm wide then 4 mm wide. What this means is that the wear marks bottom is what they call in mathematics is a chord across a rounded surface which in this case is the parabola we started with. This is just an indication of the amount of gap length that is being used up. At the end of the line is a large widening of the gap in the bottom of the pole pieces. Before this the heads still work but the response is getting close to being out of specs. This is because the boost from the Play EQ pots can not longer compensate for the lack of high end and the more you turn them up the more noise that is introduced into the playback. In the end when you see a black mark in the area of the gap that can not be cleaned off this is what we call a open gap. This means that you went through the entire head gap length and as the gap opens the record efficiency will increase but the high end will have left the building. The attached Pioneer heads were not only worn but lapped too much which as you can see is a big waste of time. There are open gaps and showing the epoxy at the end of pole pieces. These heads did not sound too good even many hours before this lapping. This should explain better to the beginner what to look for.
Pioneer and Otari heads last longer than Teac (Canon) heads because they have a slightly deeper gap length. At the same time they seem to be optimized for higher speed tape application which is why Pioneer decks have trouble getting over 20KHz at 0 Vu while I have had Teac heads go out to 26KHz in a A2300SD unit. All inside of plus or minus 2 dB.
Attached Images
File Type: jpg Heads open gap.jpg (47.2 KB, 21 views)
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Sam Palermo, BSEE and ProSquad Member
Skywave Tape Deck Repair- Chicago area
(630)616-0932 Office/ Email:skywavebe@sbcglobal.net
Past Teac/Tascam Lead Service Technician at Chicago Factory Service still doing repairs.
http://s609729863.onlinehome.us/tape...uipment-repair
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Last edited by Skywavebe; 12-07-2016 at 07:26 AM.
  #20  
Old 12-09-2016, 10:34 AM
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TEACLuke TEACLuke is offline
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Join Date: Oct 2016
Location: Austin, TX
Posts: 20
Thanks for the deatiled reply Skywavebe! It is very appreciated.

As you know, I finally took the panels off the thing last night, so now I know a bit more.

The capstan motor fan looked brand new basically (there was surprisingly little dust in the thing, I think it was covered when stored). I could not find an oil tube on the reel motors, but the one on the capstan motor was easily visible. Is seems you're saying a good automobile engine oil (10W30) is good to use. Correct?

I guess to access the tube in front, I would need to remove the front plate?

(Since this thing shows very few signs of use, is there any danger of ending up with too much oil, even if I add just 10 drops?

The capstan belt had some play, but seemed in good shape. I cleaned it with some rubber rejuvenator. I don't have the experience to know how much stretch it should have. It may be a good idea to go ahead and replace it. Do you have a recommended supplier for this?

Quote:
when I deal with the restoration and oil the bearings down each shaft which is a faster way to get oil into the bearings
Are you talking about the reel motors here? Putting oil down those shafts?

Quote:
The cap kits I change for the A6300 when purchased from Mouser is about $8.00
I was able to find a service manual with the parts list, and I've already ordered the elctrolytic caps and hope to get them soon. This unit seems quite a bit different from many other TEACs in the high number of 'spark killers' (23!). I'm happy it's just a few electrolytics that should be changed.

I have a question about this. Do you pretty much leave the power supply in place and replace them that way? The board itself seems very hard to move much, and with the side panel off, it seems you could get to the solder joints at the bottom (of the board), and there's plenty of room to lift and place the caps on the top? Does this seem like a good plan?

Quote:
You can certainly change them all over the place if you want but that can take a good day with a person who does not move like a Technician does.
Time is something I can find (though I have a couple of kids, so that's not easy either). Since this thing shows so little sign of use and lots of signs of good storage (I was told it was stored inside (climate control), I am tempted to leave the other capacitors be. I may do the old ohm meter test on a few just to see if I spot any problems.

I plan to use this thing for several years (or more!) and the thing I'm afraid of (and the reason I'm doing any of this) is that I don't want to end up having to change things later, leaving me with tapes that I am unable to play back later in a way they originally sounded.


Quote:
Brake pad are often not looked at. If they are not white and fluffy I would change the pads.
I can take a photo of them. They were certainly white, and fluffy enough to tell this was felt (or something like it), but overall fairly flat.

Quote:
A lot of this work that I am talking about may be over your head and why it is better to just have a Tech do it.
So far this is all good and I feel confident in tackling it. Taking the motor out, as you mentioned above, is the only thing I'd avoid at this point. I have time and patience, and a pretty careful hand, just not a lot of spare cash. He he. I contacted Rolf at Vintage Texas, and he is no longer taking in repair jobs; he said he's too busy. I did ask him if he had an opinion of Switched On, the local shop here in Austin, and am waiting to hear back.

I'm hoping to do as much as I am comfortable with and 100% confident I can do well. Then take it in somewhere good for some final testing and to see what I may have missed.

The pinch roller and capstan look, I think. I may go ahead and get the new rubber at some point (I did clean it with rubber rejuvenator). I've seen posts about oiling the pinch roller as well. Do you use the same oil for that as for the motor. Or is this more a job for standard machine oil?

Quote:
I could write a book but lets not do that. I am long winded enough the way it is.
I can't tell you how much I appreciate the help and information. Thank you so much.

Last edited by TEACLuke; 12-09-2016 at 08:22 PM.
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