Head groove-o-mania

[vince666]

@vince666 , I agree. I'm just seeing it from a different point of view. The available decks are getting older. No more are produced (yeah, Teac I know. C'mon). So, it's logical wear adds on them. The point is to distinguish when that wear is tolerable or it is over practical use. A photo of a head (unless the wear is extremely obvious) cannot tell you how it will perform. We have other means to test them. A photo also, can't tell you if the head can be saved. And as the good decks are getting rarer and rarer, I think it's not a taboo to rethink to save them.

As for people who mess with gear they don't have any clue what they need, well.... It's their stuff and their money....

i'd say that the point about decks being old, that there will usually be some degree of wear on the heads and that a proper test can tell you their actual conditions (etc) is true today like it was true a dozen years ago.

the only difference is that, nowadays, on top of the obvious issues they have because of their age, most of them are also messed up by clueless people who add new issues which weren't suppoused to be there only because of their age... and, after messing them up, such people go and sell them... then someone will buy a messed up deck and some technician will receive a messed up deck to work on... nowadays this happens a lot more often than a few years ago.

for example, if a head just has a wear groove (also a light one), messing with the head screws and azimuth, IMHO, is never a good idea.... but they do it just all the times.
This is because a wear groove which also gets misaligned to the tape path because they go and touch head screws can be just nasty... a groove is like adding an extra/unneded tape guide along the tape path and if they go and touch the screws it becomes like a misaligned tape guide.



anyways.....

HUH?

 

[Makymak]

This is because a wear groove which also gets misaligned to the tape path because they go and touch head screws can be just nasty... a groove is like adding an extra/unneded tape guide along the tape path and if they go and touch the screws it becomes like a misaligned tape guide.

This was the story of my Technics RS-BX808. Someone had messed with it's head tilting and height and they had adjusted accordingly the electronics to counter the losses. I was suspicious of the relative "low" price but I bid on it knowing how easy it's to repair these decks. The head was so wear out that I couldn't calibrate it. It sounded awful. I informed the seller who offered a return and accepted my findings. I didn't returned the deck as I had a spare head for it but also I wanted to try my first lapping. So, I lapped successfully it's original head and the rest was piece of cake. Then I lapped my second's 965 head during it's full restoration (it was originally bought as non working for future spares) but this is another great story of "I can repair it my self" damage. Someone had messed so much with it's transport (I don't know why, tried to change a belt?) and it was broken to pieces. At least I didn't bought it as working... So, that's why I have two working 965....

 

[Alex SE]

Well, as I said before, I'm just an amateur but regarding 965, if someone can't change a belt on it, that person is total anti-talent and should stay away from any kind of electronics. For that part of a job the one don't even need SM.
Regarding heads, the worst scenario is wrong tilt wear. Would like to lapp one of my heads from 965 but can't find all 3M lapping film I need here in Sweden. On ebay there is lot of Chinese which I don't want to try with, and self-adhesive 3M is not available. Here is interesting lapping video.

 

[vince666]

Well, as I said before, I'm just an amateur but regarding 965, if someone can't change a belt on it, that person is total anti-talent and should stay away from any kind of electronics. For that part of a job the one don't even need SM.
Regarding heads, the worst scenario is wrong tilt wear. Would like to lapp one of my heads from 965 but can't find all 3M lapping film I need here in Sweden. On ebay there is lot of Chinese which I don't want to try with, and self-adhesive 3M is not available. Here is interesting lapping video.

I am also an amateur.
And, by knowing about what you just happened to do on your decks in the past, I'd say that you are someone who takes care about what he is doing, tries to study the situation before doing anything, etc...
Then, over time, you will surely get better and better because you try to learn to do things the proper way.

The clueless people I was meaning on my previous posts are just nothing like this... they just make things (usually very wrong things) BEFORE trying to understand what's going on and without trying to study the situation and how to make things properly... and this is the differences between making damages or, little by little, fixing things.

That video about relapping is good for R2R heads which don't have the guide on and it's quite just what you can read on the nortronics guide which is around the net as a pdf file... of course, it's faster and easier to lap a head with no guides on.
Anyways, that glass he keeps under the lapping film looks a bit too thin, though... for sure, it's thickness is not enough to "bypass" the guides of a cassette head... better to go with a glass which is about 1cm thick.
Also, that lapping film doesn't look self-adhesive... which is not a big problem if you can lap like that at the center of the lapping film sheet because the head has no inbuilt guides... but if you have to lap with the guides on (like it usually happens with cassette heads) , then you need to work near the edge of the glass and then a small strip of lapping film has to be self-adhesive to stay in place properly without slipping off the glass.

it happened only once to me that I could lap a cassette head like that at the center zone of the sheet, because the head was missing its own guide.
It was a NOS head, on which I only had to apply a very light lapping to polish a few scratches made into the box where it was kept in the shop here below for years without the protection cap and rubbing against other heads in the same box.
So, I've lapped it without guides on and managed to reattach some suitable guides only after lapping it.
But, of course, if the guides are just on the head, it's better to leave them there because it's not easy at all to reattach the guides at the proper place/height so that they are well aligned to the head gaps. (to be able to do that, I had to design and DIY a suitable tool)... it needs a tiny guide alignment error, like 0.1 millimeter, to just get misaligned tracks which will give you a significant level error while swapping tapes between decks.
The total width of the track of one channel on a stereo cassette is only 0.6 mm.

 

[Alex SE]

I see that he is using non adhesive film and is his case lapping is a piece of cake since a heads he is lapping are without guides. Lapping sandwich heads is something else. Never tried lapping but I can imagine that it takes time and time. Found these on Amazon. Don't know if it is something to use.

 

[vince666]

a funny anectode about a TOTALLY clueless guy I've recently met on an italian facebook group about cassettes...

The guy had a very old mono shoebox recorder, a very rare early 70's model from the japanese brand Silvano, so rare that there isn't even a picture of it on the whole internet.
The guy only wished to put a new capstan belt and realign the speed, because it did run very slow after putting a new belt on...
So, seeing the bad and dangerous advices he was getting there in the group, I simply replied him to do NOTHING and to rely on a proper technician.
A couple days later, the guy did write me a private message by explaining that the recorder didn't work anymore and that he had opened the motor.
At first, I was simply trying to give him a few advices through messenger but I've soon realized that the guy was so clueless that he didn't even have a voltmeter to check voltages... so, to avoid that he got electrocuted while working on that recorder, I told him to send me the recorder so that I would have checked what was going wrong.
When the recorder came here and gave it a look, I was really shocked...

The guy, after opening the motor, upon rebuilding it, he soldered the motor's wires while putting so much solder that he did short the positive on the motor's chassis... but he was lucky because he had re-soldered the other end of the wire (going to a small PCB) with both wires wound together and soldered on the same place... so, the bad short he made on the motor side wasn't really a short on the PCB/supply side but it was simply like a disconnected wire. (he was just lucky!)
Then I opened the motor and found that he had bent the brushes... that motor was a very robust model and so I was able to get it running again...

So, the motor worked again... and it was a motor where you cannot tune the speed (I had not investigated if the speed tuning trimmer was somewhere on the PCB though)... anyways, it did run slow because that mechanism wanted a square belt of 1.2 mm thickness and he had put a walkman belt of 0.6 mm thickness which wasn't just able to turn the capstan flywheel properly... so, I've put a 1.2 mm thick belt on it and the speed was just quite OK.

Then, by trying to play a tape (luckily a not important tape) , I've noticed the tape got damaged... the old pinch roller was totally gone... then I've replaced the pinch roller with a new one... but the deck did still ruin the tape...
So, I've checked the tape path with a M300 gauge and it was off quite everywhere...
At that point, before going to touch the heads' screws, I wrote a message to the guy asking if he had also touched the heads' screws... If he didn't, I would have kept into consideration that one was the factory alignment, even if it looked wrong... but he did actually touch the head screws too (why not? )...

But, since I was telling him, step by step, all the unneded rookie errors and damages he did on that recorder, he felt sort of offended and replied to me that, to tell him so clearly what I've found out about his "fixing attempt" I was being not that much polite and he also told me that, regardless of the damages he had done on it, since I had offered to fix it (and I was doing that for free!) , it was my own responsibility and not his own anymore....
So, after hearing about this, I simply packed the damned thing as it was, without finishing to fix it, and putting back the old original pinch roller and the wrong walkman belt he had put on it and sent it back to him.

So, not only the guy did not listen to my own initial advice to NOT TOUCH IT but to send it to a proper technician, not only he wasn't telling me "thank you" because I was trying to explain all the damages he did on it, not only I was doing all of that for free... he also implied that the responsibility for his own damages was mine, since I accepted to work in it... then, a HUGE F#@K OFF to him and his stupid recorder was just the minimum from my side.

Go figure... this is just to give you an idea about all the pointless morons around lately, who believe that to be a technician is sufficient to own a screwdriver and a crappy chinese soldering iron and that knowledge and experience are not important at all.

 

[vince666]

I see that he is using non adhesive film and is his case lapping is a piece of cake since a heads he is lapping are without guides. Lapping sandwich heads is something else. Never tried lapping but I can imagine that it takes time and time. Found these on Amazon. Don't know if it is something to use.

how can I know what that lapping film really is?

anyways, if those numbers mentioned on the page are microns (i.e. the 1500 = 30 means 30 microns)... then the coarser one at 30 microns is too coarse... the coarser one to use should be the 15 micron one and I am seeing they go down to the 0.3 micron one... so, as far as grit goes on, they offer all the needed ones and maybe also some more.

I cannot understand the language on that page, though... do they say if it's self-adhesive or not?
also, any ideas if the abrasive material is Aluminium Oxide?

that said, it might be good for the task, if self-adhesive.

 

[Makymak]

Vince you had much patience with the pathetic moron, there!

When I returned to the analog sound and bought my first deck, a Technics RS-BX606, I had already done my homework to make it run properly. Go figure, the deck cost me 40€ and the tools to service it (including test tapes) over 400€. But I never regret it. This deck was a huge school for me and I learned a lot. Never touched a single screw before studying the manual and mostly, before I could understand what every adjustment is doing. And I'm thankful that exist helpful experts that are willing to help.

 

[laatsch55]

a funny anectode about a TOTALLY clueless guy I've recently met on an italian facebook group about cassettes...

The guy had a very old mono shoebox recorder, a very rare early 70's model from the japanese brand Silvano, so rare that there isn't even a picture of it on the whole internet.
The guy only wished to put a new capstan belt and realign the speed, because it did run very slow after putting a new belt on...
So, seeing the bad and dangerous advices he was getting there in the group, I simply replied him to do NOTHING and to rely on a proper technician.
A couple days later, the guy did write me a private message by explaining that the recorder didn't work anymore and that he had opened the motor.
At first, I was simply trying to give him a few advices through messenger but I've soon realized that the guy was so clueless that he didn't even have a voltmeter to check voltages... so, to avoid that he got electrocuted while working on that recorder, I told him to send me the recorder so that I would have checked what was going wrong.
When the recorder came here and gave it a look, I was really shocked...

The guy, after opening the motor, upon rebuilding it, he soldered the motor's wires while putting so much solder that he did short the positive on the motor's chassis... but he was lucky because he had re-soldered the other end of the wire (going to a small PCB) with both wires wound together and soldered on the same place... so, the bad short he made on the motor side wasn't really a short on the PCB/supply side but it was simply like a disconnected wire. (he was just lucky!)
Then I opened the motor and found that he had bent the brushes... that motor was a very robust model and so I was able to get it running again...

So, the motor worked again... and it was a motor where you cannot tune the speed (I had not investigated if the speed tuning trimmer was somewhere on the PCB though)... anyways, it did run slow because that mechanism wanted a square belt of 1.2 mm thickness and he had put a walkman belt of 0.6 mm thickness which wasn't just able to turn the capstan flywheel properly... so, I've put a 1.2 mm thick belt on it and the speed was just quite OK.

Then, by trying to play a tape (luckily a not important tape) , I've noticed the tape got damaged... the old pinch roller was totally gone... then I've replaced the pinch roller with a new one... but the deck did still ruin the tape...
So, I've checked the tape path with a M300 gauge and it was off quite everywhere...
At that point, before going to touch the heads' screws, I wrote a message to the guy asking if he had also touched the heads' screws... If he didn't, I would have kept into consideration that one was the factory alignment, even if it looked wrong... but he did actually touch the head screws too (why not? )...

But, since I was telling him, step by step, all the unneded rookie errors and damages he did on that recorder, he felt sort of offended and replied to me that, to tell him so clearly what I've found out about his "fixing attempt" I was being not that much polite and he also told me that, regardless of the damages he had done on it, since I had offered to fix it (and I was doing that for free!) , it was my own responsibility and not his own anymore....
So, after hearing about this, I simply packed the damned thing as it was, without finishing to fix it, and putting back the old original pinch roller and the wrong walkman belt he had put on it and sent it back to him.

So, not only the guy did not listen to my own initial advice to NOT TOUCH IT but to send it to a proper technician, not only he wasn't telling me "thank you" because I was trying to explain all the damages he did on it, not only I was doing all of that for free... he also implied that the responsibility for his own damages was mine, since I accepted to work in it... then, a HUGE F#@K OFF to him and his stupid recorder was just the minimum from my side.

Go figure... this is just to give you an idea about all the pointless morons around lately, who believe that to be a technician is sufficient to own a screwdriver and a crappy chinese soldering iron and that knowledge and experience are not important at all.

No good deed shall go unpunished Vince!!

 

[vince666]

Vince you had much patience with the pathetic moron, there!

When I returned to the analog sound and bought my first deck, a Technics RS-BX606, I had already done my homework to make it run properly. Go figure, the deck cost me 40€ and the tools to service it (including test tapes) over 400€. But I never regret it. This deck was a huge school for me and I learned a lot. Never touched a single screw before studying the manual and mostly, before I could understand what every adjustment is doing. And I'm thankful that exist helpful experts that are willing to help.

Sure... but I was both worried of the moron getting electrocuted because he was just clueless about everything and, nevertheless, he was working on the device open and connected to AC plug...
also, it was a so rare model (also very heavily built for a mono shoebox recorder!) that I felt sorry that such a pointless moron was simply destroying it... it had got to arrive from 1972 to 2022 in pretty good shape and it needed just a little work, but the right work... and he was simply destroying it for good.
Anyways, in the end, he deserved that I sent it back to him without really fixing it... basicly, before sending it back, I've just removed a couple shorts here and there for safety reasons... ah, and the motor brushes back in place as he had bent them.

For the rest, I am the same as you... I never manage to touch ANYTHING before getting the proper tools, studying the service manual and getting a minimum of knowledge/information to at least avoid damaging things.... and, if still in doubt about something, I simply stop and manage to find further informations before going on.

No good deed shall go unpunished Vince!!

indeed.

 

[laatsch55]

It doesn't stop me either Vince...

 

[vince666]

It doesn't stop me either Vince...

but you can always go on safely, my dear.

 

[J!m]

Well, as I said before, I'm just an amateur but regarding 965, if someone can't change a belt on it, that person is total anti-talent and should stay away from any kind of electronics. For that part of a job the one don't even need SM.
Regarding heads, the worst scenario is wrong tilt wear. Would like to lapp one of my heads from 965 but can't find all 3M lapping film I need here in Sweden. On ebay there is lot of Chinese which I don't want to try with, and self-adhesive 3M is not available. Here is interesting lapping video.

Try Struers for metalograpgic preparation papers. You can also purchase grit paper adhesive from 3M which turns regular paper into adhesive paper.

 

[laatsch55]

but you can always go on safely, my dear.

Amen!!

 

[vince666]

but I was both worried of the moron getting electrocuted

and, to be fully sincere, years ago when I was working on my own decks for the first times, I risked a couple times getting electrocuted myself... then I became sensitive about this matter.

i.e., some AIWA decks have the small PCB with 220V AC just dangerously close to the deck's mechanism (just besides the mechanism, where other decks usually have the headphones amp PCB) then it needs just a tiny distraction while working on the mechanism to actually touch the 220V AC zone... on such decks, I immediately managed to cover that zone with insulating tape, after risking getting electrocuted.

anyways... nobody can beat my dad... rather than checking if there was any AC with a voltmeter, he usually preferred to check a wire with his own fingers... and, to be sure to make a good contact, before touching a wire with his finger, he made sure to wet it with some saliva.... funny that he did that not only on single phase 220Volts but also on tri-phase 380Volts... he told he knew how to "taste" the current without keeping attached to it, like touching the wire with the back side of his finger.... who needs a voltmeter?

 

[Makymak]

I risked a couple times getting electrocuted myself

My first interaction with the lovely 220V was at the age of 2! Since then, I had many intercoarses with different kind of voltages (from 50V to 2kV). The worse was a rectified short of 600V, I was stuck there and saved me the safety features...

Anyway, Vince, this is more than serious. I know a lot of people who don't know neither care about safety measures. When someone is ignorant, it is very easy to harm himself, first.

As for dads, I remember mine fixed the house electrics with only a screwdriver!!! Old school speaking... and respect!

 

[vince666]

My first interaction with the lovely 220V was at the age of 2! Since then, I had many intercoarses with different kind of voltages (from 50V to 2kV). The worse was a rectified short of 600V, I was stuck there and saved me the safety features...

Anyway, Vince, this is more than serious. I know a lot of people who don't know neither care about safety measures. When someone is ignorant, it is very easy to harm himself, first.

As for dads, I remember mine fixed the house electrics with only a screwdriver!!! Old school speaking... and respect!

OMG! Those 4 of 5 times in total that I was hit by 220V AC was more than enough for me and it wasn't funny.

First couple times when I was a child and the plugs here in Italy had the pins fully made of metal, now they are half plastic half metal then you cannot risk to get hit by current while simply inserting a plug in the wall.

And, yes, safety is IMPORTANT and there are so many people who do ignore it totally, yet they don't fear to open a device while it's plugged in and touching here and there.

Sure... total respect for dads... they are super humans! (mine actually was, as we've lost him about 10 years ago, though)

 

[Makymak]

Sad to hear that, Vince...

 

[vince666]

Sad to hear that, Vince...

no worries... he got a really great life, full of satisfactions and was in really great shape until age 90 (he looked and acted like if he was like 20 years younger)... but then he improvisely got a cancer and that's it... but he got a nice life and he was/is a great example for us all.... if he was alive today, he would be 102... but his grandmother passed at 108, though.

of course, after 10 years, we are starting of getting used of his phisical absence, also because at now it's easy to think about him by recalling just the nice and funny things about him and smiling for that (he had great sense of humour too)... but, really, I still miss him a lot.... anyways, I like to think he is always somewhere around here, giving me that sort of unexpected help which sort of comes out of nothing, just anytime I might need it.

 

[Wheel-right]

Our parents are always with us, since we have aged, we are them, just listen to what you say. I hear my parents talking.