Ye Olde Cassette Tapes, for Audio & Data !! - Page 1
Forum section: electronics / general

author: GlennSprigg
author_rank: Super Contributor
timestamp: March 21, 2018, 12:56:27 pm
content: I've seen a few YouTube videos recently, talking about the high audio quality still attainable, using cassette tapes!especially (or only xx) when using high quality players/decks, and of course in conjunction with HQ tapes !!!Be that as it may, I've got 2 comments to make, to add to this, to interest Musicians & Data-Recording people....(1) I play the Guitar, and often I find myself in a position to PLAY ALONG with 'CD's... Now 'modern' CD digitalrecordings are always accurate & in 'Key', (no pitch shift from the original). However, a LOT of the 'Oldies', havebeen transferred from old TAPES, to CD's, and there-in lies the problem for me. Although the apparent QUALITYof the 'recording' seems good, different tape PLAYERS due to their archaic physical mechanisms of belts, gearsand rubberbands, and varying 'strain/tension' on the tape, often results in SLIGHTLY OFF PITCH play-back, whichdoesn't matter if listening to THAT alone, but totally ruins attempts at real-time accompaniment !!! (Clear as mud x).Yes, I can edit it on a computer, with fractional pitch-shifts etc, but it's still a pain !!(2) I'm also a retired Technician, and NOT SO LONG AGO, was not only the advent of 'PLC's, (Programmable LogicControllers), but a time when we didn't use a 'Computer' to store the programmed data, but a CASSETTE TAPE tostore the data via a simple AUDIO Jack In/Out connection !!! Which 'recorded' the screeching 'blips' etc which onecould say was like one of the first D/A & A/D converters..... Hey... it was almost better than sex, hearing it !!!It took me a while, after many experiments, to convince my boss at the time, that his expensive 'fancy' tape-playerwas a FAILURE !!!... What we NEEDED was the cheapest, most junky-sounding & 'tinny' player found, for $8.95 !!!WHY??...... I didn't CARE about pleasing 'Audio' quality.... 'Fancy' machines ruined/modified the 'sound'....Tonally destroying the DELIBERATE high speed audio "Glitches".... which was the peaks & troughs of the DATA !!!Just something to share for nostalgia..... Be careful how you "filter" actual DIGITAL.... Back to my Bubbly now

author: Brumby
author_rank: Unknown
timestamp: March 21, 2018, 03:33:23 pm
content: You've grown up with typewriters, haven't you?I know it's probably the way you type, but you don't need to add carriage returns unless you actually want to start a new paragraph. Trust the computer to start a new line when it is necessary.Depending on the scaling of the page in each member's browser, you can end up with text that's a little challenging to read. In my case, I get a full line of text followed by a line with one, two or three words, which is then followed by another full line and another one, two or three words - and so on. Yet, these line breaks have nothing to do with paragraph changes - just two or three sentences spread across a dozen lines or more.As I said - it's probably how you've always done it - and you might even hear the "ding" in the back of your head when you type....As for your comment on the music, I can only offer you my sympathies for being a guitar player - but the issues of tape transfers is one I can readily understand - and the digital tape storage issue was one I had never considered - but it explains why the first TRS-80 machines came out with the cheap piano key cassette machines.

author: Ampera
author_rank: Super Contributor
timestamp: March 21, 2018, 03:45:29 pm
content: I actually would love to see something like an analog helical scanning audio tape. I could very well be wrong, but I don't believe I've seen an audio only tape using helical scan to get a better effective tape speed.To play dumb for a second, does increasing tape speed just increase frequency response, or does it also improve the SnR for analog audio recordings? I've honestly forgotten.

author: AndyC_772
author_rank: Super Contributor
timestamp: March 21, 2018, 03:56:56 pm
content: Many years ago I worked for a company making multi-channel voice recorders, which were based on VHS mechanisms with bespoke electronics. They were telephone quality, but used analogue FM recording with a helical scan transport. IIC they'd record 32 or 64 channels for many, many hours on a slow moving VHS tape.Later on there was DAT, of course, which uses helical scanning too.To the OP: Could you perhaps get a professional / DJ player with speed and/or pitch control?

author: rdl
author_rank: Super Contributor
timestamp: March 21, 2018, 04:47:03 pm
content: I seem to remember audiophiles recording music (only) on Hi-Fi VCRs being a thing for a while. That was a long time ago though.

author: Ampera
author_rank: Super Contributor
timestamp: March 21, 2018, 05:03:05 pm
content: Hi-Fi VHS recorded audio digitally, while regular VHS also did video.I'm not saying it doesn't exist, or never existed, but a true, dedicated, helical scan analog audio recorded would be neat to have. Maybe someone could use .25 inch reel to reel tape and a borrowed tape mechanism to try to do something (or just hack a VHS/Beta machine).

author: floobydust
author_rank: Super Contributor
timestamp: March 21, 2018, 06:02:24 pm
content: No, Hi-Fi VHS was FM encoded helical scan, no digital at all. On an old NEC N895 I repaired.

author: helius
author_rank: Super Contributor
timestamp: March 21, 2018, 06:13:27 pm
content: Hi-Fi VHS does not use digital audio. It is an analog FM modulation scheme, similar to the analog audio tracks on Laserdisc (not the digital audio tracks).The reason you would never use helical scanning for an analog tape format is the head switch discontinuity, which did affect Hi-Fi VHS decks.

author: Ampera
author_rank: Super Contributor
timestamp: March 21, 2018, 06:22:59 pm
content: Whoops, got my formats confused there. Don't blame me, I'm stupid. Or you could blame me I guess. No clue why I thought it was digital.EDIT: I think I was confusing myself with Laserdisc's digital sound capabilities.I'm just saying, despite it's issues, it would be cool to see.

author: SeanB
author_rank: Super Contributor
timestamp: March 21, 2018, 06:36:55 pm
content: There was a high fidelity digital audio recording scheme for VHS tapes, that did use an ADC to convert the stereo audio to a 16 bit digital audio stream, and also did a lot of forward error correcting and shaping, so that it was compatible with a video signal, and thus was recorded on the video helical scan tracks, while at the same time ( because it was there already) the FM audio and the linear stereo audio was also recorded as well. Was quite capable as well, and in fact many CD masters were made with this doing the final mastering, as it was capable of handling the data rate quite easily, and was a lot cheaper than using a massive ( by the standards of the time) hard drive array that could store the Gigabyte of data needed, plus it was portable and you could easily make a duplicate using a standard video duplicator, so you had a backup of the tape before sending to the pressing plant, where it was played back to create the original glass CD master.Not seen much at all outside the recording and video industry, but Matsushita did quite a few of them.Other methods as described above used the FM audio capability of the VCR, running at EP speed with a locally generated composite video signal. Full frames with line and frame sync, correct equalisation pulses and colour burst, and either all black video or a test pattern, so the video sync circuit was going to track correctly and keep tape speed constant via the standard chipset servo loops. Up to 8 hours of good quality audio on a regular E240 tape was possible, and it would still work during seek, though the audio was horribly distorted. The audio distorting during head switching was mostly solved in the HiFi audio by arranging the track switching so that there was a period of overlap in the tape wrap so the audio FM decoder was supplied with both head signals and simply chose the highest amplitude one during the head change period, as the larger head for the depth recording read slightly wider area of the tape and this allowed silent switching. you would occasionally have a very slight low level purr with poorly adjusted machines, either the original recorder or the player, but overall the performance was pretty good, and as the standard there was to have an always on Dolby noise reduction in play you had a pretty good audio signal. Was at least equal to the best analogue tape when correctly set up and using good quality tape base.

author: Zero999
author_rank: Super Contributor
timestamp: March 21, 2018, 07:10:32 pm
content: Quote from: Brumby on March 21, 2018, 03:33:23 pmIt's fine on my HD computer screen, but I imagine on a phone or tablet, it will be difficult to read. Resizing the window makes it look like this.Anyway, back on topic: audio cassettes were very popular for storing software on for early home computers. I remember going to a relative's house as a child to play computer games and having to wait for the computer to transfer all the data from the cassette to RAM, before the game would run. I can see why ROM cartridges were popular because they loaded instantly, even though the capacity was lower and they were much more expensive.

author: GlennSprigg
author_rank: Super Contributor
timestamp: March 24, 2018, 12:23:47 pm
content: Thank you for your reply, 'Hero999', (and 'Brumby').....(The other replies were interesting and informative though)Yes you are right, and I never mentioned all the other 'Pre-PC' machines like the 'Commodore-64' etc etc. Yep... cheap players and cheap tapes to preserve the so called 'digital' data being recorded ! (How and why is a subject of it's own). Thanks mate !!!Although off topic, but ofinterest(?) is my reasons for the way I 'type'... (or did !......)......Yep... I think I used a mechanical typewriter, once or twice, in the late 1960's or early 1970's, however since the advent of the 1st PC in existence, and writing software for nearly 30 years, I've always structured what I 'type', in the way of 'indents', 'REM' statements and hierarchical boundaries & loops, so as to be readable on most basic 'terminals' since then.... And if I structure a 'paragraph' containing numbered or bulleted parts, then I 'try' to make the result look like "meaningful blocks" of text...... Especially if the 'reader' is viewing something on an extremely high-res screen, which these days is often the case(Even my old Samsung S4 'smart-phone' is 1080 x 1920 pixels, although allowing easy 2 finger zooming if required).However, I guess I failed, for Idid notaccount for people using less than say '1024' pixel width these days, which of course would have resulted in unusual word/line wraps. May I apologize to those affected. May you all have a great day/night.....

author: GlennSprigg
author_rank: Super Contributor
timestamp: March 24, 2018, 12:30:03 pm
content: P.S. Just for fun !!!!!When i started the topic with the words... "Ye Olde".... this is commonly a misconceptionThe old so labeled 'YE' is a misnomer where the "Y" 'letter' was a fancier curved symbol which meant "TH".It was never 'sounded' as 'Yea'....

author: Ampera
author_rank: Super Contributor
timestamp: March 24, 2018, 04:49:01 pm
content: You mean þis symbol? I've actually been researching older (and even more modern) Insular Celtic længuages, as well as older versions of þhe English længuage. As a result I've gotten a bit enamoured wið older alphabætical symbols, pronunciations, etc.

author: ebastler
author_rank: Super Contributor
timestamp: March 29, 2018, 07:48:00 am
content: Quote from: GlennSprigg on March 21, 2018, 12:56:27 pmYou may or may not be aware already: You can buy CD players with "pitch control", i.e. an old-fashioned knob or slider directly on the front panel to adjust pitch.They tend to come in strange form factors -- think ghetto blaster or 19" rack mount -- since the main use seems to be for Karaoke... Asking Google about "cd player pitch-control" should give you an idea what's available.

author: Circlotron
author_rank: Super Contributor
timestamp: March 29, 2018, 10:15:30 am
content: Quote from: SeanB on March 21, 2018, 06:36:55 pmI used to feed in the video signal of a game console while recording audio. Worked really well back in the day. Could record almost an entire overnight radio session when there was hardly any advertising.

author: Red Squirrel
author_rank: Super Contributor
timestamp: March 29, 2018, 06:40:44 pm
content: One time I kinda humoured the idea of using VHS for data backup using a VCR. Not sure how I would have accomplished that but think I had read up on the idea and it turned out I could not actually hold all that much information compared to say flash drives, so it was not really worth pursuing. Though it would be kinda fun as a project just to say that it can be done. I'm thinking it could just store the data as largish pixels (to account for any quality loss etc) and then an audio stream. The write would be easy enough to do, essentially just need to generate video/audio data. The read would be more tricky though. Like not sure how to go about "reading" video and audio.

author: meeko
author_rank: Contributor
timestamp: March 29, 2018, 07:45:48 pm
content: Quote from: Red Squirrel on March 29, 2018, 06:40:44 pmBack in the 90's, my uncle had a card and software that did just that. IIRC, I think it could store something like 800MB on a T-120 tape?

author: helius
author_rank: Super Contributor
timestamp: March 29, 2018, 08:16:36 pm
content: The easiest way would be to use chips intended for VITC encoding/decoding on line 16 and force them to work over the entire video area.

author: mathsquid
author_rank: Frequent Contributor
timestamp: March 30, 2018, 12:24:05 am
content: Quote from: Circlotron on March 29, 2018, 10:15:30 amI did something similar in the 90's. A classic rock radio station did a top 50 albums of all time, and I used my VCR on EP to record six hours of music on one tape. It seemed really cool at the time.

author: SeanB
author_rank: Super Contributor
timestamp: March 30, 2018, 06:47:52 pm
content: Quote from: Red Squirrel on March 29, 2018, 06:40:44 pmHardware was from a UK company called Danmere, and was a single ASIC on a ISA card to do the whole lot, and did actually work well, though the data rate of 40Mb per minute was not the highest, but beat the pants off of either using boxes of disks, or the expense of a QIC drive and SCSI adaptor.I had this and the software, and used it, and later on graduated to a used QIC drive and tapes ( they grew too small for the company and were replaced with DAT) and now just use hard drives instead to back up locally. Looking for a used tape drive though and media.