You are pushing your luck with that on any but seriously pro kit. Th pre-emphasis on the treble means you only have a few db range above 10kHz.
Which is why disks and data tapes use a completely different encoding system.
Id say a fast tape - 15 ips or more would net you perhaps 60dB at 2Khz bandwidth if reliability needed.
Tape was truly AWFUL.
CD MUCH better.
Id doubt that a tape was capable of delivering much more than a good modem over a phone line, 64kbps.
Bandwidth and S/N are similar. so 8KB/s
You only need to look at the mess that videotapes were on all but massively expensive kit at stupendous speeds to see that getting to the Mbps was almost impossible
The first digital audio recorders used video tape transports. Indeed the CD 'red book' was based on how long a standard U-Matic tape ran. So it would be fair to call it a memory - just not a RAM one. ;-)
You'd have to define more clearly what you mean by "only have a few db range above 10kHz" before I could comment. Can you point to some measured results that show this? If not, I may have a swan though old AES material to see what I can find.
Again, you'd have to be more specific wrt details wrt the basis of your belief. Bearing in mind of course that speech and music don't normally have a uniform power spectral density, etc.
Also bearing in mind that most of the music recorded before c1980 for commercial release or by the BBC was onto analogue tape rather than a digital system. Yet can sound pretty good nowdays if it was recorded and kept well.
Curious to know how you get to claiming that R2R tape and a phone line having the same bandwidth and SNR.
My little tape recorder had a non-standard speed of 4ips and also had the tape wound in a funny way so it played backwards on a normal machine. For tapes I used to strip down 1/2" computer tape. My uncle worked at IBM and he used to get it for me.
Well, there's some small element of truth in what you say[1] but the point I was making was that it seems so futile to 'archive' gigabyte's worth of audio and terabyte's worth of TV recordings and mpeg movies onto optical disk media of questionable durability and limited capacity.
As a backup medium (other than for bootable storage for OS installs and stand alone software diagnostic tools for use on older PCs that don't properly support booting from USB flash memory devices), the limited storage capacity and writing speeds detract immensely over that of the utility of hard disk storage whether it's in the form of a simple external USB drive or a NAS box full of HDDs.
A modern 4TB WD RED drive represents about a thousand DVD-R disks (and around about 200 Blu-Ray disks), so the costs per GB of optical storage is somewhat similar but without the convenience of HDD and with a huge performance penalty (less than 25% the speed at best if you forgo the verification pass required to assure that the data was successfully written to the media - in practice, with verified writes, the time penaly is more like getting a mere 10% of the backup speed of HDD based storage.
Life's just too short to waste on such 'pre-historic' archival methods (and space so limited too - I gave up using DVD-R archival storage after writing some 400 DVD's worth when the cupboard started getting full).
I decided that I would do just as well using the homebrewed FreeNAS box (now running NAS4Free) to archive my growing collection of media files, upgrading the jbod array of disks piecemeal to to keep pace with my ever increasing storage capacity demands.
I've now got a total storage capacity of 13TB's worth of HDDs in the NAS box and looking to upgrade the smallest (2TB) drive to another 4TB WD RED by the end of the year.
I'm looking forward to the larger 6TB units becoming available at a less than eye watering price before the end of 2015. I've been running a file server of one sort or another for almost the past 3 decades now and it's rather sobering to think that it all started with a 300MB full height ESDI HDD in an NEC Powermate II (8MHz clocked 80286 CPU) running NW 3.11) connected to a 'CheaperNet' lan.
I've now got some 40,000 times that storage capacity today and I dare say I'll almost certainly have 100,000 times the original storage capacity before the end of this decade.
[1] As a matter of interest, I was listening to an MP3'd episode of the Goon Show whilst I was reading your post which I'd extracted from a 7GB stereo wav file captured from a 24 hour internet radio broadcast just over nine years ago.
I'm pretty certain I deleted the original 7GB wav file once I'd processed it into a 54 episode MP3 collection because I couldn't afford to tie up so much disk space. It'd be a different story today now that 7GB is such 'a mere trifle' on a 4TB disk but back then, it wasn't so trifling. Oh, how things have changed in less than a decade!
The station, afaicr, was called "GoonShow Radio" and had a repetoire of 54 episodes contained in its daily endlessly looped output. I used Winamp to capture the stream and send its output to a wav file, letting it run for just over 24 hours. This proved sufficient to captue all 54 episodes with an episode or three spare.
I'd previously been listening directly to the audio stream for a few days before, noticing that they were simply repeating a limited number of episodes every 24 hours, and realised that I could archive the lot by leaving WinAmp to run for just over 24 hours. I'm glad I did because the station dropped out of existence a week or two later.
The point is that the original stream was just 64Kbps mono (a reasonable match to the AM radio broadcast quality most listeners of the day would have experienced) which, being MP3 rather than the crappy MP2 standard of DAB was quite sufficient quality (no bubbling mud effects so typical of a 64Kbps mono DAB broadcast).
Mind you, a higher bit rate would have been appreciated but this was just over 9 years ago when bandwidth was at more of a premium. The source material was almost certainly taken from the original studio recording tapes which could have justified higher bit rates to emulate FM radio quality rather than the AM radio quality it was re-broadcast in.
Be that as it may, I still enjoy listening to these shows despite the limitations of the low bit rate mono MP3 storage method (24 hours worth packed into the space of a single data CD!).
I've digitised a portion of my reel to reel tapes and vynil to wav files which I _have_ retained. The 192Kbps stereo MP3s which I carefully crafted for 'easy listening' purposes are almost indistinguishable in quality from the original wavs.
The deficiencies only become obvious when I use the "3D Surround" options on the PC speakers which uses anti-phase cross mixing to simulate a wider stereo image otherwise the straight playback of this material seems to be just fine to my aged ears whenever I bother to compare the MP3 against the original wave file playback.
If I wanted to create a compressed archive of all this audio material, I'd choose a lossless format to preserve the original detail in the wav files regardless of my own hearing abilities. The storage costs for digital audio, even with flash media, is cheap enough these days to call into question the value of lossless compression.
Lossless compression eliminates unnecessary redundency making the task of reconstructing the original from a moderately corrupted compressed file all the more problematic.
I f you want to add an extra level of robustness against 'bit rot' in the storage media, an effective way is simply to duplicate or even triplicate the archive files since the ddrescue application can recreate a bit perfect copy from such corrupted duplicated backups. IOW, use two or three times the storage media for each backup and keep ddrescue on hand to refresh your archives as soon as your annual 'spot checks' reveal the first signs of 'bit rot'.
All archival methods need some level of maintenance to retain their integrity over protracted periods of time. Even well proven ink on paper materials need to be checked from time to time even if it's a matter of maintenence intervals measured in half centuries.
With modern digital storage, we'd be pushing our luck with 5 year maintence intervals. The only saving grace being the ease with which exact duplicates can be created on replacement and novel media. Optical disk storage lost its 'Novelty Factor' decades ago hence my regard of CDs and the like as being positively 'pre-historic'.
Not sure Tony. Never actually saw one. The first digital recorder I came across was IIRC the 610 - which used a Sony Betamax as the transport. That had a slightly wider video bandwidth than the low band U-Matic. It was short lived as DAT arrived soon after.
Yup, but I bet that in 10 minutes you could have taught her how a reel-to-reel worked and she would have pretty much understood. No chance of that with modern mp3 digital equipment.
Thats the biggest difference between the tech of my youth and now - old stuff was understabndable to the average person.
On a related note, I looked inside a TV that we were binning last week. Just 2 small circuit boards with precious few components. A triumph[?] of modern design. The TVs of my youth were full of glowing valves and thick cables. A thing of wonder, but now look like something from a Jules Verne film.
How many components in a valve TV?
Incidentally, check out 'photonics' for some amazing old electronics... eg:
I really craved one of those. They were always advertised in the back pages of the various hobby magazines. It was never clear what you needed to do to hook it up to the amplifier so I never bought one.
Ditto - originally I thought MP3's were inferior [to CD] because they were not lossless compression (like zip), however for most purposes you really can't hear the difference.
PS typical digital audio streams are 44 - 48k samples per second.
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