Cassette lovers; why?

[George S.]

The M-300 gauge clone is available on AliExpress for much less money. A second version with brass screws is also available. Sure looks like each style are coming out of the same factories, just a multitude of sellers with same product.
What the brass screws are for I don't know, but I'm going to find out.
The Chinese Abex tapes are reported to be good.
"Made in Japan" products like some of the Teac tapes out of China are very suspect I think.

 

[Chris Cables]

The M-300 gauge clone is available on AliExpress for much less money. A second version with brass screws is also available. Sure looks like each style are coming out of the same factories, just a multitude of sellers with same product.
What the brass screws are for I don't know, but I'm going to find out.
The Chinese Abex tapes are reported to be good.
"Made in Japan" products like some of the Teac tapes out of China are very suspect I think.

I recently went through a process of exploring the possibility of having a batch of the IT-M300 gauge replicated to equal or better than the original spec. (1/100mm tolerances for flatness, perpendicularity etc)
RFQ's were sent out to multiple machine shops but nothing materialised unfortunately. All the shops here in NL are in high demand and the shop I was really hoping would produce a quote, my ex-neighbour, who is probably the most capable out of all of them couldn't come through for me either.

I posted about it on TH. Nakdoc and ypsilon were helpful in providing info re. their own negative experiences and I received all manner of snipey, dismissive personal messages as well as the asshole mods there delaying/deleting my posts, replies and updates.

A mod even closed the thread when I advised I was putting it on hold for the time being. What a prick. Why close it? I may have had a positive update and got the project back on track!
Either way, if it does gain momentum again at some point then I won't be announcing it there, that's for fkg sure!
Assholes.

 

[George S.]

Yeah Chris, I read every post about the M-300 on TH and elsewhere.
I'm wondering if it is truly a critical tool to have.

 

[J!m]

I think if you're swapping (or just removing to lap) heads, you need it.

I looked into having them made years back as well, but there are more options now.

I would suggest getting a couple cheap ones and verifying the tolerances, and then making corrections as needed. No one wants to make tight-tolerance gages for cheap. Doing this gage "right", using proper tool steel materials with all surfaces ground and (in some cases) lapped and a finish applied (plating or controlled oxide such as bluing or blacking), the gage will be near to 2k USD. But THAT will be a proper gage. You won't get a critical gage for ~$200.

 

[Makymak]

I'm wondering if it is truly a critical tool to have

It's a tool to align and check the tape travel. It's a very critical alignment when servicing a dual capstan deck but of minor importance on the majority of single capstan decks, as they usually have fixed head and guide points. The dual capstan needs an exact alignment or else the head contact will be insufficient and/or the tape will skew or even worse, been eaten. A very experienced restorer can align the tape path with a mirror cassette (which is cheap and can be homemade) but it's not the safe way. A mirror cassette should be used in conjunction with the m300, to reveal a problematic behavior of the transport.

I received all manner of snipey

Welcome to the group!

 

[Chris Cables]

Yeah Chris, I read every post about the M-300 on TH and elsewhere.
I'm wondering if it is truly a critical tool to have.

Put it this way; I have one and use it as a good starting point when calibrating/refurbing decks, especially if the head/s have to come out for any reason.
The Chinesium ones are useless in my experience. I bought one and we put it on a height table and measured 8 points over the surface. The largest deviation between 2 points was 0.1mm which is a country mile outside the flatness tolerance that the IT design spec calls for!

You can't trust them for head height or tilt therefore but head depth penetration is probably doable - you can verify that dimension relatively easily.

I also discovered that the 'other' non-Chinese gauge that was being produced by a certain well-known entity wasn't actually within the design specs either. Hence why he may have stopped selling them.

J!m is correct to allude to the fact that there is a direct correlation between accuracy and cost and I'm assuming this may be why some of the shops I approached turned me down flat- due to the fact that they already knew it would be a tough ask to meet the demands of the RFQ, so why waste time trying.

I'm really hoping my ex neighbour HenkJan can find some time to attempt a pilot batch. He does a lot for aerospace and I know the fkr loves a challenge. He built his own plane and got it certified for airworthyness and flew it within a year.... in his spare time!!

 

[ButchJames]

Just me mumbling on this topic:

I have looked at these Chinese gauges (and their 'ABEX' tapes) , and continued to look, and look, and look ......

A waste of money? Maybe, some are very cheap, I think I've seen some at 'just' £30 Sterling, but what am I getting for that kind of money? And how much statistical variance is there between samples?

 

[J!m]

If there's enough stock on to bring the main plate into tolerance via surface grinding, it may be worth doing. I've ground many non-magnetic materials - we just stick the part to the chuck with double-sided tape. We also grind the surface of the chuck after it is bolted down so you have parallelism between chuck surface and travel axis within 0.0001" (usually tighter on a good machine).

You could potentially coat a thin plate with epoxy and grind the epoxy if it's already too thin. Or make a wider indicator to account for the plate thickness being undersize.

These options are less expensive than a scratch build...

 

[vince666]

about the cheap gauges at Aliexpress...
a friend got one a while ago and thickness of both the plate and bar was totally wrong and by a lot... like if they didn't even know the correct size.
But there might also be good ones, then buying from there is a sort of lottery.

 

[Makymak]

Unfortunately, a slight deviation from the correct dimensions can get the alignment way out of the specs. Head and guides hight can be verified with a mirror tape up to some level but penetration (when applicable) and especially tilt is very difficult without an appropriate "type-m300" gauge. And it's not only the plate's grinding accuracy. It's also the bar that counts (although the bar should be easier to manufacture to specs).

 

[vince666]

funny that also the thickness of the cassette shells has some tolerance... in fact, if you measure with a caliper you will notice they aren't all the exact same thickness.

 

[J!m]

I think there are locations that are tighter tolerance but not all dimensions need to be tight.

 

[Chris Cables]

funny that also the thickness of the cassette shells has some tolerance... in fact, if you measure with a caliper you will notice they aren't all the exact same thickness.

The cassette shells play a less critical role in the optimum position of the tape relative to the heads. The tape guides are more critical and mirror tapes can help to identify a good/poor relationship between shells, rollers and guides. It's also the reason why you can actually put your finger on a shell and move it around in the XY plane while the tape is playing without any undue effect.

 

[Makymak]

Furthermore, don't forget about the slip sheets. At a very large amount of shell designs (like TDK) they are not flat but have folds and act like shock absorbers between the tape reels and the shell while keeping the reels centered in a loose shell.

 

[Chris Cables]

Furthermore, don't forget about the slip sheets. At a very large amount of shell designs (like TDK) they are not flat but have folds and act like shock absorbers between the tape reels and the shell while keeping the reels centered in a loose shell.

True, but that's a TDK-specific design/marketing aspect and not something that's included in the Philips 1962 cassette tape standard, hence it probably helps but doesn't strictly need to be present to keep the tape centred. BASF also patented the SM mechanism which was a design aspect to keep the spooled tape inside the cassette shell uniform and flat. Again, not strictly needed but was probably helpful. Sony had things like 'ceramic' tape guides built in to the UX-Pro, which are actually just plastic and nothing special and probably didn't help that much - again marketing bollocks to try and keep manufacturers ahead in tape sales by selling spuriously innovative cassette shell designs.

My Little Sony, skinny and boney. Made of white plastic, nothing fantastic.

 

[Makymak]

Of course the TDK design differentiated from the Philips CC standard. That's why they needed to make thinner shells to accommodate the folded slip sheets.

With the cassette success and after it got been a mainstream format, every manufacturer took their own way improving the cassette. This led to a "polyphony" of innovations and differences between shells, mechanisms and formulations. Thus the difference between shell thickness.

On the other hand, manufacturers of the decks stood strictly close to the initial tolerances, so the transport alignment (and the tools to service) has to follow these specs.

My 2 cents...

 

[J!m]

Here's a "why do I love cassettes" answer:

Listening in the car to a TDK SA I recorded on sub-par equipment in 1985 or so, and it still sounds good. (still need new rear speakers in my car if anyone can help!)

Cassette technology evolved. The Philips standard was the start- they already invested millions in development of the format and had no reason to invest millions more in the cassette itself. What if it flops? They allowed the outside companies (Sony, TDK, Maxell, Memorex) to spend their R&D money on that.

As long as the exterior dimensions, transport pickup points and tape width are adhered to, the internals are open season. Like endless cassettes for answering machines. I don't think Philips created a standard for that (but I could be wrong), yet it works just fine in a standard cassette player.

 

[Bob Boyer]

One of these days I'm gonna get a deck for the Suburban that plays CDs and cassettes. The Delco player in my ZR-2 did both, which is why I got the Nakamichi from Tom. I need to see if I can find one of those and whether it will fit or not as the navigation system/screen in the 'Burb is useless. Get 50 feet off a highway on a forest service road and it doesn't know where I am.

 

[ButchJames]

Just airing some not unrelated thoughts ...

Back in 1963 the cassette was never intended to be a HiFi medium, and if it were, then I would suspect that the design would have been more 'robust', and possibly allowing for 1/2 track versions with provision for playing 1/4 track recordings in mono on a 1/2 track machine? The speed would bit a little faster (say 5cm/s to 6cm/s), and the tape width - possibly 1/4" as opposed to what we have now? I am aware that there was another 'cassette' which someone pointed out to me a few years ago, but never 'took off'. BUT, as someone in TH said - convenience wins in the market place; how very true.

When we think about it, the format is quite sensitive to slight misalignment; this shows up when recording-playback to and from other machines. And then there's shell differences to contend with. It's all a bit of a mess, but as many of us are cassette fans, we live with it.

I have about 30 cassette decks and have set about so that they can all Rec/PB to and from each other with little serious impact on frequency response and azimuth instabilities. Forget precise Dolby compatibilty of course - that's another subject, which just happens to bring me to the Music Cassette. How many in here have noticed that the PB of some of these tapes with 'Dolby' marked on is a hit-and-miss affair!? Yes, I'm aware that high frequencies are somewhat partially attenuated with time, but some of these manufactured 'Dolby' tapes are way off.

 

[J!m]

Sony made the larger cassette (Nando has some) that was designed to be hi-fi from the start with true 1/4" tape inside if I'm not mistaken.

Then there was DAT, which I liked the idea of, but never had spare cash to buy into. Sony ES DAT decks were nice looking.

Finally CDR, which is where I got on the train. "Quaint" now-a-days, but making your own CDs back then was a very big deal... I still can make CDs at will but haven't in a while as my son has gotten out of listening to CDs on his "boom box" at home. That'll probably change and I'll be teaching him how to make his own...