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Topic: "Pursuing the 90's" with compact audio cassette tapes. (Read 8287 times) previous topic - next topic
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"Pursuing the 90's" with compact audio cassette tapes.

It might be something tightly localized to my location (Western Europe), but I've seen a couple of my friends adding audio cassette tapes to their collection of "vintage" audio formats.

It seems that format slowly enters the mysticism and affection realm of Vinyl...

Anyway, it kinda makes sense, given that in the (late) 90's audio cassette technology kinda peaked. Using type IV tapes for best quality is a given, but I was wondering which tape heads and drives are considered good quality. When acquiring a tape machine, what should I look for? I pretty much only know it should have tape selectors or tape sensors, so it's compatible with the higher quality tapes.

So what sort of tape heads should I look for? All I know, is the higher quality devices used three heads (like the better Nakamichi or Revox tape decks). However there seems to be some preference when it comes to the actual heads themselves.

Another big item is noise reduction. A device that supports Dolby S would be great to have, but I'm a little confused by the selections of noise reductions available. I've seen machines with just a switch labeled "Dolby NR", but it doesn't say which one it is (Dolby A, B, C or even S). I assume it used either one of Dolby A, B, or C, depending on when the device was manufactured.

I'd also like to get my hands on different types of noise reduction systems, like "High Com" and "dbx".

I know there are some companies resuming production of audio cassettes, or new companies forming that produce them, like http://nationalaudiocompany.com/ .

I wonder if there are still high quality tape deck manufacturers.

One of the few sources that I draw on, is a video made by Techmoan: https://youtu.be/jVoSQP2yUYA "Cassettes: better than you don't remember".

Handling tapes is not as involved as Vinyl, but the sound quality (given the right tapes and the right equipment) is very adequate, and pretty fun for itself. I guess from this post it's pretty clear, that I'm interested in kinda getting into cassettes a little bit. I guess the main reason is it brings me back to being a kid and teenager. The machinery and handling tapes i just fun in itself, and getting the best possible quality is a nice bonus. Me and my parents never had a large collection of tapes. My dad never liked them, he considered them utterly inferior to Vinyl. He was a big fan of CDs, but he somewhat skipped tapes.

I'm sure there's one or two tape aficionados on HA, that would like to share their knowledge? I'm mostly interested in recording my own music and audio on tapes. Pre-recorded tapes don't interest me as much.

Re: "Pursuing the 90's" with compact audio cassette tapes.

Reply #1
If a consumer tape deck says simply "Dolby NR", that means it's got Dolby B only. Tape decks with Dolby C are backwards compatible with Dolby B and of course decks with Dolby S are backwards compatible with both B and C.

Dolby A and Dolby SR were/are used for commercial recordings, and aren't relevant in a consumer tape deck context.

In my opinion, you should go for a single-well deck with dual capstans, triple heads and direct drive, if possible. Go for Dolby S and Dolby HX-Pro. Avoid decks with auto reverse and other such gimmicks. Brands such as Nakamichi, Revox, Tandberg are the usual suspects for high-quality tape decks, but don't discount more "common" brands such as Pioneer, Yamaha or Sony. They made some really nice decks in their higher-end product series.

If you want to use alternative noise reduction schemes, look for separate devices that you can plug into the signal chain. Don't bother searching for tape decks with eg. DBX built in.

Finding type IV tapes these days is going to be hard, but type II tapes can deliver reasonable sound quality, too.

Re: "Pursuing the 90's" with compact audio cassette tapes.

Reply #2
Compact audio cassettes have the disadvantage of noise, wow and flutter. But they do not have the disadvantages of vinyl, e.g. crackles, pops, noise of vinyl discs and RIAA eq curves used for preparation to manufacturing vinyl discs (although this can help keep dynamic range reasonable comparing to some recent badly mastered CDs).

Dolby B is the most universal noise reduction and works very well and is the most compatible. Dolby C and S is very highly sensitive to head azitmuth alignment thus has limits within practical usage, although it has even higher noise reduction than Dolby B (if that is neccessary). Also there is Dolby HX PRO that is used when recording only and works well - I recommend to use it for home recording.

IEC IV tapes are very expensive and rare today. IEC II type CrO2 70 us tapes have good frequency response (17 000-18 000 Hz typical) and often are used for high quality home analog recording (and were used for music distribution, sometimes with CrO2 120us variation for that). Some of better  IEC I Fe 120 us tapes also provide very good sound and reasonable frequency response. Good deck have automatic tape recogition I/II/IV so you do not have to adjust for playback of different IEC types manually.

Analog sound is still a viable alternative. Many artists do analog recordings on reel-to-reel at the studios even today. Even if the digital 24/48 recording is technically more "precise" (no doubt about it). Compact cassettes have evolved nicely during years and the best of them are in majority of parameters comparable with lower range reel to reel machines.

All in all, if you can get a good deck with IEC II (or IV if you have access to cheaper IV type tapes), Dolby B/HXPRO (or C) NR and well adjusted tape mechanism (azimuth, speed), you can get good analog recorder for home use.

Re: "Pursuing the 90's" with compact audio cassette tapes.

Reply #3
OK, I thought Dolby HX-Pro was pretty much an exclusive to expensive professional studio equipment and Bang & Olufsen devices. I'll look into finding Tape decks having that.

As for sources of tapes: I might come across a bunch of Type IV tapes, but they're quite old and not stored correctly (garage, cold, rel. high humidity). Do tapes break down over time? I.e. can they damage a tape head, because the plastic substrate or the ferromagnetic layer started to break down?

Re: "Pursuing the 90's" with compact audio cassette tapes.

Reply #4
HX-Pro was readily available in mid-tier tape decks since the early '90s.

I used cassettes throughout the '80, and up until the mid-'90s for the car and recording jam sessions.

I wouldn't waste even a second of my time with them today.

Re: "Pursuing the 90's" with compact audio cassette tapes.

Reply #5
Do tapes break down over time? I.e. can they damage a tape head, because the plastic substrate or the ferromagnetic layer started to break down?

Yes, absolutely. The worst part is that they get sticky, so old tapes can tear themselves apart when you try to play them.

People who restore old media sometimes bake the tapes at a precise temperature for a set amount of time to counteract this, but it's usually only good for one or maybe two playbacks. And I've never heard of anyone doing it to cassette tapes, only reel-to-reel master tapes.

As Greynol said, the cassette tape just isn't a very good format. I have a couple of old tapes lying around for nostalgia's sake, but I'd never use tapes for actual music playback.

E: Apparently cassette tapes aren't really affected by "sticky-shed syndrome", but there are other weaknesses: https://en.wikipedia.org/wiki/Sticky-shed_syndrome

Re: "Pursuing the 90's" with compact audio cassette tapes.

Reply #6
I don't have a specific recommendation because I don't know what's available.   I wouldn't recommend the cheapest thing you can find, but I wouldn't go overboard either.     There's only so much sound quality you can get out of analog tape (or vinyl) and IMO it's silly to spend lots of money on something that's never going to sound as good as a cheap CD or MP3 player.

Quote
Me and my parents never had a large collection of tapes. My dad never liked them, he considered them utterly inferior to Vinyl. He was a big fan of CDs, but he somewhat skipped tapes.
That was me too, except I used to record my records to the best cassettes available for listening to in the car.    I never bought a pre-recorded cassette.

I didn't like the hiss or the high-frequency roll-off with cassettes.  The "snap", "crackle", and "pop" of vinyl was super-annoying too,  but overall a new record sounded better to me.   

I never had an 8 Track, but my parents did.   I didn't like it changing tracks in the middle of a song.
 
I have a cassette deck in the closet with DBX, but I don't remember if I ever used DBX because it wouldn't play in the car.        It probably doesn't work anymore...  I assume the belts & rubber drive wheels are dried-out...


...VHS Hi-Fi has better "specs" than any other home analog format and some people used to use it audio-only.

Re: "Pursuing the 90's" with compact audio cassette tapes.

Reply #7
I wouldn't waste even a second of my time with them today.

As Greynol said, the cassette tape just isn't a very good format.

I fully understand. I'm not pursuing actual playback capabilities, it's more a question of playing around with it. Pretty much purely because of nostalgia and the retro appeal. People play around with 8-Track for the same reasons. I'm not fully Techmoan on that, but he also does this sort of rare / old audio formats, because it's kinda fun playing around with it. Getting the best sound possible out of it, is basically nothing more than a personal challenge, without going full audiophoolery about it.

Anyway, thanks for the insight so far, I'll try to get my hands on a good condition tape deck, and first thing I'm gonna do with it, is test it, and see if I can repair it, if it needs to (I'm kinda planning on getting a non-functional machine, just to have a bit of fun repairing it). I'll keep this thread alive when I get the deck and start work on it.

I wouldn't recommend the cheapest thing you can find, but I wouldn't go overboard either. There's only so much sound quality you can get out of analog tape (or vinyl) and IMO it's silly to spend lots of money on something that's never going to sound as good as a cheap CD or MP3 player.

Naturally. Btw. 8-Track was never a thing in Europe, really. Also, cassette tape decks in cars were seemingly very prone to eating the tape. I remember my dad never used the FF and REV functions on his car tape deck, because it would de-spool the tape inside the machine. Playback was fine, though. Also, I've heard about car tape machines doing that to tape from various other sources, and I've witnessed it once myself.

Re: "Pursuing the 90's" with compact audio cassette tapes.

Reply #8
FWIW, this was the first stereo I owned personally.  It had all the bells and whistles a 13-year-old could want that was affordable at the time: double cassette (with Dolby, peak meter and stereo level adjustment for recording), digital tuner, turntable, 5-band graphic, 3-way speakers.  It was purchased from Macy's.  This particular model was not very common.

Re: "Pursuing the 90's" with compact audio cassette tapes.

Reply #9
Here's a completely moronic video on the subject that I saw recently:

(too bad I can't manage to get the forum board to support <a rel="nofollow"></a>)

Oh well...
Someone needs to smack this idiot.

Re: "Pursuing the 90's" with compact audio cassette tapes.

Reply #10
Here's a completely moronic video on the subject that I saw recently:

(too bad I can't manage to get the forum board to support <a rel="nofollow"></a>)

Oh well...
(link to youtube video)

...mother of god. He ripped-off Techmoan and managed to explain less about the subject matter. Also, I find his smugness and looks incredibly aggravating.

Re: "Pursuing the 90's" with compact audio cassette tapes.

Reply #11
Given the choice, go for a deck with adjustable bias. Back in the day, I had a mid-level deck that I fitted a glass-filled head to and it had internal presets for bias level. I used one type of tape exclusively (can't remember which) so I went to the trouble of setting the bias up for that tape alone. It does make a noticeable difference but as you well know it isn't going to compete with CD.

If you buy a non-functional deck you are likely to have fun trying to source any parts needed. If there are any belts in the drivetrain (highly likely) they'll be scrap, for starters. A lot of later decks used largely plastic mechanicals, these were generally poor for longevity. Decks with pressed/stamped metal mechanicals are far more solid and durable.

Re: "Pursuing the 90's" with compact audio cassette tapes.

Reply #12
And if you really enjoy the fiddly stuff, go on eBay and buy a Teac Open Cassette and a bunch of blank reels...


Re: "Pursuing the 90's" with compact audio cassette tapes.

Reply #13
Given the choice, go for a deck with adjustable bias. Back in the day, I had a mid-level deck that I fitted a glass-filled head to and it had internal presets for bias level. I used one type of tape exclusively (can't remember which) so I went to the trouble of setting the bias up for that tape alone. It does make a noticeable difference but as you well know it isn't going to compete with CD.

Oh, OK, I didn't know setting the bias hysteresis is even possible like that. I imagine you used an oscilloscope to tune the bias level and hysteresis?

Most tape decks I have repaired in the past, had pots for tuning the bias, but I've only did it according to a service manual, and with an oscilloscope attached to the bias PLL.

If you buy a non-functional deck you are likely to have fun trying to source any parts needed. If there are any belts in the drivetrain (highly likely) they'll be scrap, for starters. A lot of later decks used largely plastic mechanicals, these were generally poor for longevity. Decks with pressed/stamped metal mechanicals are far more solid and durable.

Getting new belts isn't that difficult, except if they have really peculiar lengths (lengths >25cm in a single belt, for instance). Drivetrain belts are still made by a number of manufacturers (one of which is 3M), because they're still used in machinery other than home audio.

As for the Polyester cogs and plastic parts it's "meh'": I've replicated Ppolyester cogs on my CNC milling machine and CNC lathe, but when it's tiny plastic parts in thin, weird shapes that need to be injection molded (especially when it's low-impact Polystyrene), that's where I usually draw the line and replicate the part from aluminium.

The parts that I can't replicate, are things like face plates, silk screened decals, clear plastic windows, chrome, and rubber parts.

And if you really enjoy the fiddly stuff, go on eBay and buy a Teac Open Cassette and a bunch of blank reels...
(image)

I've seen them in a video on Youtube. They're pretty low quality, though. It's all plastic, etc. if it was all metal, etc. it might've been nice (with high quality tape on the reels etc).

Re: "Pursuing the 90's" with compact audio cassette tapes.

Reply #14
As I have written good tape deck with Dolby B/C/HXPRO is still the viable alternative (not counting reel-to-reel) for home analog recording and playback. It cannot compete with digital accuracy, however. A pity that new IECII CrO2 tapes in Europe usually are not available (only old stock/used) , abroad the company that has been mentioned http://nationalaudiocompany.com/ works but they are not available e.g. in Czech Republic where I live, only IEC I tapes.

Re: "Pursuing the 90's" with compact audio cassette tapes.

Reply #15
It might be something tightly localized to my location (Western Europe), but I've seen a couple of my friends adding audio cassette tapes to their collection of "vintage" audio formats.

Some people have an interest in cassettes because of the content, which may not be available in any other format. Many bands released music locally on cassettes due to cost and ease of reproduction. Small budget, local music is being preserved by people digitizing such older material, which would otherwise be lost. Indeed, it is a great time to be into cassettes, as used high end players and prerecorded tapes are now quite inexpensive.

In my opinion, a good cassette deck and a good tape recording can be quite adequate in terms of listening enjoyment.

Blank no-name CrO₂ tapes can be bought at tape duplication businesses. There are still some people using cassette tapes commercially even now.
Quis custodiet ipsos custodes?  ;~)

Re: "Pursuing the 90's" with compact audio cassette tapes.

Reply #16
I have a Technics RS-AZ7 that I inherited from my grand father I am surprised how great cassettes sound. I hae used Ferro and cobalt Type II tapes.

1. When I record I can switch between listening to the recorded sound the direct sound and I can not hear a diffrence except from the noise if the cassette is of good/acceptable quality. I don't find the low noise a problem. Using Dolby B or C it is almost non existing to my ears.
2. If there is a silent passage I can hear very very low amount of cross talk if I use no Dolby B or C.
3. If the tape is of bad quality I can hear minor wow and flutter. Between the two I have tested I consider SHX 60 Cobalt of less quality and this one sometimes give off the artifacts.
4. The SHX 60 Cobalt Type II does not work too good with automatic bias/eq calibration which adds excessive treble. I am wondering if this is because this tape attenuates high frequencies more than the Maxell SQ Ferro Type II cassette. I tested them by sending white noise and adjusting the recording level. Therefore when I play with these for fun I do not use automatic calibration with the cobalt ones.

All in all, I am extremely surprised by the sound quality. I did however buy a Guttermouth cassette produced this year and the sound quality was awful. I would really like to know how the manufacturing plant managed to create such bad sound quality.

Maybe I will record some audio samples where I switch between recorded and direct sound.

Re: "Pursuing the 90's" with compact audio cassette tapes.

Reply #17
I also have some tapes that have very good quality. Some of the have music from 60s and 70s (recorded on that tape later of course). Maybe since then was everything recorded on studio tapes I am accustomed to that analog sound.

Dolby is very sensitive on correct head azimuth alignment. Noise perceived is associated very much with playback volume.

Yes automatic tape calibration (available on some decks) works for majority of tapes very well and for a minority of them does not. It is better to use good brands like Maxell, TDK, BASF, Sony, etc.

Re: "Pursuing the 90's" with compact audio cassette tapes.

Reply #18
Dolby is very sensitive on correct head azimuth alignment. Noise perceived is associated very much with playback volume.
Playback itself is greatly influenced by head azimuth alignment. Matching the original alignment of the recording head, or at least being close is important. Most decks allow for azimuth correction at the service level but it's not easy to do on a tape by tape basis. In this regard some cassette decks allow the alignment of the playback head to be easily adjusted. Such decks can have the playback head aligned so as to exactly match the alignment of the original recording head and therefore extract the most information possible. If one is interested in listening to a variety of tapes from a variety of sources, such a feature can make a substantive difference in achieving consistent playback quality.
Quis custodiet ipsos custodes?  ;~)

Re: "Pursuing the 90's" with compact audio cassette tapes.

Reply #19
Yes, fully agree. However it is best to maintain one adjustment to avoid readjusting frequently - not good for the screws and head mechanism (yes some highly advanced decks have automatic azimuth adjustment but I have seen such a deck only once physically). Many tutorials are on the web to adjust azimuth manually. Most simple is to take 2-3 well recorded commercial tapes and adjust "by ear" on average for the most of high frequencies (adjusting done without Dolby on even if tape is recorded in dolby). More sophisticated tutorial is here http://www.ant-audio.co.uk/Tape_Recording/Test_Tapes/AudioTester_azimuth_set/album/index.html
 
Or you can use tape with e.g. 3 kHz, 10 kHz and 14 kHz recorded on factory-calibrated machine.

Re: "Pursuing the 90's" with compact audio cassette tapes.

Reply #20
And if you really enjoy the fiddly stuff, go on eBay and buy a Teac Open Cassette and a bunch of blank reels...
(image)

I've seen them in a video on Youtube. They're pretty low quality, though. It's all plastic, etc. if it was all metal, etc. it might've been nice (with high quality tape on the reels etc).
I suspect that most purchases were made by companies who wanted a really kewl-looking cassette for the catalogue shots of their latest deck.

Re: "Pursuing the 90's" with compact audio cassette tapes.

Reply #21
Yes, fully agree. However it is best to maintain one adjustment to avoid readjusting frequently - not good for the screws and head mechanism (yes some highly advanced decks have automatic azimuth adjustment but I have seen such a deck only once physically). Many tutorials are on the web to adjust azimuth manually. Most simple is to take 2-3 well recorded commercial tapes and adjust "by ear" on average for the most of high frequencies (adjusting done without Dolby on even if tape is recorded in dolby). More sophisticated tutorial is here http://www.ant-audio.co.uk/Tape_Recording/Test_Tapes/AudioTester_azimuth_set/album/index.html
 
Or you can use tape with e.g. 3 kHz, 10 kHz and 14 kHz recorded on factory-calibrated machine.
The head alignment must only ever really be changed, when the head is misaligned due to changing heads, or when the head gets misalined inside an auto-reverse deck, where the head swivels around. On decks where the head is stationary, it's very unlikely (i.e. almost impossible) for the heads to get misaligned. Often, the adjustment screws are glued into place with resin, so you can see if people tried to tamper with it.

Adjusting the heads on a three-head machine is a little bit more complicated, and only makes sense when the record or play head is changed.

I've always adjusted the new head to the already existing head in the machine. I've changed play heads a couple times, but the record head only once.

Each time I've used Type II tape, with a 20kHz tone.

I don't know if there is a correct service approach to setting the alignment for the record head. I've simply attached my function generator to the input, set it to a 10kHz tone, and had my scope attached to the output of the head pre-amp. I then adjusted the record head while the machine was recording the 10kHz tone.

It worked fine, but as I said, I'm not sure it was the correct way of doing it to "factory standards".

Re: "Pursuing the 90's" with compact audio cassette tapes.

Reply #22
Seems to me as a very good approach to maintain good alignment.

Re: "Pursuing the 90's" with compact audio cassette tapes.

Reply #23
The head alignment must only ever really be changed, when the head is misaligned due to changing heads, or when the head gets misalined inside an auto-reverse deck, where the head swivels around. On decks where the head is stationary, it's very unlikely (i.e. almost impossible) for the heads to get misaligned. Often, the adjustment screws are glued into place with resin, so you can see if people tried to tamper with it.
There are decks which have a knob which allows the playback head azimuth to be easily adjusted to match the recording azimuth of the currently playing tape. I have such a deck; when I play a tape, I can adjust the knob so I hear the most high frequency sounds.  It's easily done and the audio difference is obvious. This makes such decks ideal for listening to tapes from a variety of sources as each tape playback can be optimized in terms of matching the azimuth between the recording deck and the playback deck. Some advanced decks can do this automatically for each tape.

As well, some decks may also have a bias tune knob so you can match the bias of the recording tape as well. I have had great success getting audio from tapes at better quality with such a tape deck. O:)

Naks with azimuth adjustment ~  http://www.tapeheads.net/showthread.php?t=849
Quis custodiet ipsos custodes?  ;~)