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VCR modification to sound like R2R

I vaguely recall the blurb the OP mentioned - I think it was in one of the mainstream mags like Stereo Review back in the mid/late 80s. From my hazy memories the blurb didn't mention any technical details so who knows what the hack was. I suspect it used the rotating video heads to exclusively record audio without having to shoehorn it into the VHS video format.

Given that now you can record gigabytes of 16/44 (or better) audio on an ipod-like device, the VCR hack isn't much more than a curiosity.

On a side note I bought my first new VCR back in 1988 and picked an Aiwa model with audio only recording, adjustable recording level and an easily read VU meter. Made hundreds of audio only recordings on it because I was sick of flipping cassettes when taping FM radio. Now for the rare times I want to record something I use my PC/laptop with a USB ADC. Editing said recording is childs play and I wouldn't go back for all the tea in China.
 
If you can connect it up. A PC using windows media player with WAV files or windows loselees mode is much easier to use. You can make custom made song lists and change them on the fly. You wont be stuck with a long sequence of tunes that will be difficult to index using the fast forward button.

Plus you can transfer any song list to a portable player too :thmbsp:

You can almost think of a hard disk as a R2R cross pollinated with a CD player. :D

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I don't remember if the digital VHS recorder that I saw in the early 80s was Technics or not, only that it was pretty cool and I had never seen one like it before.
 
LexDM3 said:
Sony had a Hi-8 audio only recorder if I remember correctly. This used 8mm videotapes but used the whole tape for audio. No video. I don't recall hearing this done with VHS but I think that better VHS decks "striped" audio along with video rather than do a linear recording along the edge of the tape.
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You may be thinking of a thing SONY made called DAT (Digital Audio Tape).
They were very well made and had some awesome specs. They used tapes about the same size as 8mm.

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If this thread is indeed about using VHS Hi-Fi to record audio, I've done that. Lots of it. It is certainly much better than cassette, but it really isn't all that great in my opinion. I detailed some measurements I made in this thread and was glad to graduate up to DAT and never look back. I've since moved on from DAT as well.
 
I played with VHS hifi recordings in the early days. They were indeed very good. But finding the album you wanted on a 6 hour tape, much less the song was a serious chore. So I gave it up. DAT sounded similar, but did everything better.

R2Rs can sound significantly better than HiFi VHS. But it depends on the deck, the tape, the speed and how well calibrated everything is.
 
At the time, having no interest or experience with r2rs, VHS HiFi and Beta HiFi was a wonderful experience for watching videos and finding out it could also make wonderful extended audio recordings, something I believe was never an intended use:)
 
coonmanx said:
I don't remember if the digital VHS recorder that I saw in the early 80s was Technics or not, only that it was pretty cool and I had never seen one like it before.
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Yes it was. Technics thought they could sell this beast to prosumers who were too intimidated by the VCR/PCM combos of the day. I never saw one of the Technics models but at a hamfest I once saw one rebranded as a laboratory data recorder. IIRC it still had the VU meter display and such - quite a strange beast. No idea what it was used for but there weren't any major case modifications so it was probably just recording a two track analog signal.
 
A two track analog input which was what the Technics had as an input. There might have been an interface for digital data input on that rebranded laboratory data recorder.
 
I remember Sony has a "SoundStream" device that was used with a Sony 2500 Beta VTR. I believe Telarc used it to record the 1812.
 
steerpike2 said:
"Hi-Fi" video recorders have an inherent s/n ratio at the tape/head interface of about 45dB. To get the claimed 80dB they use a companding noise reduction system (like dbx) which gives the numerical doubling of dynamic range, but doesn't fix the poor signal to noise ratio. That means that depending on the material, and the loudspeakers, you can hear the head-switching noise, and you can hear the noise reduction system adjusting the gain. It's way way better than the linear audio, but it is not a match for a competent R-to-R.
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No, it is not at all how VHS-hifi is done. The hifi tracks are recorded in FM (not PCM as some posts might seem to imply) by specialized heads on the same drum as the video heads. There is no companding involved because it is not necessary to achieve a good SNR with FM recording. Automatic level control is the usual suspect for the effects you hear. My parents had a JVC HR-S5000 which was one of the first VHS-hifi models on the market, with manual level control, and it didn't have this "pumping" effect. Actually it sounded good until some day it lost alignment and it became impossible to read the hifi tracks. Interestingly, the later hifi models of the make lost the manual adjustment and suffered from the typical "ALC pumping" sound. Hifi, oh yeah, sure :rolleyes:

But all the other points are perfectly valid and inherent to the VHS-hifi system: it's extremely sensitive to alignment, and machine to machine compatibility is next to impossible. One should be aware of these issues while making the decision to record in VHS.

BTW in reply to the OP, I've never heard of a mod to make a VHS "audio only". Most VHS decks are able to record audio even without a video signal on their input, but I don't suppose it is the meaning of the OP. It was possible to use a VHS as a stero digital recorder with the Sony ADC designed for the SL-F1 portable Betamax (at that time it was pretty much fashionable to use a VCR for digital audio recording), that might well be recorder in question. There was also the ADAT which was a digital 8-track recorder using S-VHS tape, and the Nagra-D (for digital) that used a VHS heads but specific 1/4" tape, but that's all that was marketed in terms of audio recorders related to VHS. Nothing analogue that's for sure.

UPDATE: after checking the specs of VHS hifi, such as this, it turns out there is companding, although not DBX. And pre-emphasis too. However the recording is done in FM as I said, so the 45dB dynamic range does not apply. I and Steerpike were both wrong in some way :) And both right in that VHS hifi has issues that don't allow to make it a good audio recorder.
 
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There was an addon to the 8mm video standard - I believe it was audio only - that recorded 8 bit digital audio and used companding ala dbx to achieve "digital" quality. I think it was only seen in later Sony models.
 
Many years ago I had a HiFi VCR, I think it was a SVHS either Panasonic or JVC, that could record PCM audio only, and even though I never used it for that purpose, the sound quality was supposed to be excellent, better than any consumer product. Plus you could get 24 hours of music in a single 120 minute SVHS tape.
 
gonzothegreat said:
There was an addon to the 8mm video standard - I believe it was audio only - that recorded 8 bit digital audio and used companding ala dbx to achieve "digital" quality. I think it was only seen in later Sony models.
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There are mentions of this PCM Hi-8 in the literature, e.g. the wikipedia. 32 kHz sampling, 8 bits resolution: that's not even close to VHS-hifi, let alone a decent RtR. Companding is mentioned in some sources, but not that it is done "a la dbx". Actually, in digital it is much easier and far better to use nonlinear quantification, feeding the samples through a look-up table - this is how the long-play mode of DAT reduces 16 bits into 12-bit words.

BTW Hi8 PCM is not audio-only.

There was also a "PCM multi audio" mode, recognised only by 3 models, providing 6 stereo channels. but you couldn't record or play more than one at a time. These machines were made in the mid-eighties and the format is notorious for its fragility, so I wouldn't pay too much for one, especially considering the questionable sound quality. There was a thread here on the one of the 3 models in question.
 
jlb2 said:
it turns out there is companding, although not DBX. And pre-emphasis too. However the recording is done in FM as I said, so the 45dB dynamic range does not apply. I and Steerpike were both wrong in some way :) And both right in that VHS hifi has issues that don't allow to make it a good audio recorder.
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I said it was like dbx, not that it was dbx. The companding is very much like DBX, in that it is a decilinear. It does not however use RMS level detection.
The 45dB dynamic range applies most definately, whether it is FM or not.
FM is required on all rotary head recorders - for the video signals as well.
You will see that they get only about 45dB of s/n ratio on the video signal too. Same goes for audio. Maybe you misunderstand.. i'm talking 45dB at the tape/head interface.... that's where the 1.4 and 1.8MHz signals are being recorded. FM helps sort out the problems you'd get with the level variations caused by the shock waves of the head impact on the tape each time it starts a half rotation.
Since it switches heads twice per frame, there is a tremendous 50Hz (or 60Hz in america) noise component on top of the audio... companding is very necessary to get past that. And it is very audible, on machines that do not have auto level control too.
 
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