How were commercial tapes mass-recorded?
 

I haven't been able to find much on the topic, though i imagine probably similar in concept to audio cassette mass production. Was this just a case of having many recorders work off of a master device, or was there specialty all in one equipment used?

They were most likely recorded on Betacam SP and later on Digital Betacam and progressed to HD using pro gear, From there copies made in the publishing company's studio and distributed to broadcasters.

I have some of those broadcast Betacam SP tapes, They contain the whole news segments and commercials, I think they were used as a backup for reruns. I captured one of them and edited out the news, Not much to see through youtube compression but it gives you an idea on how good the quality was.

https://youtu.be/N0qwTjLTtQU

I remember a friend of mine had a summer job working at a company that made video reproductions for purchase. They had 600 VHS VCRs working in tandem to reproduce consumer copies of the Spider-Woman cartoon. The cassettes were all hand inserted and hand removed. I asked her if there was any way to speed up the recording process as you could do with audio, but she told me that it was all recorded in a one-to-one ratio: 30 minutes for 30 minutes.

Masters were VHS.
- Lowest budget used consumer VHS VCRs. Recordings were crap, even SP. Maybe TBC, maybe not.

Masters were non-VHS
- Low budget used commercial/industrial VHS VCRs in racks, TBCs.
- High budget used the contact method. Remember tape is magnetic.

I don't think commercials were ever produced on VHS, They were all pro formats, Unless the OP is talking about those workout and some other products videos destined for consumer use, then yes.

The contact method that used for audio cassettes probably would not have worked on VHS in my opinion since it uses a deep layer HiFi audio recording scheme, I can see that possible for Betamax and VHS with linear audio. Though I'm not entirely sure how consumer VHS were mass produced.

As lordsmurf stated, large run commercial prerecorded tapes were done with contact printing machines:

http://www.otari.com/support/vintage/t710/index.html

http://www.digitrakcom.com/TechDocs/SONYsprinter.pdf

Yes I've seen those materials few years ago, I could never understand how two magnetic layers are being recorded by contact.

You're thinking in terms of there being two physical layers of data recorded in VHS Hi-Fi. It's not. There's only a single physical layer of magnetic particles on any magnetic tape. This largely goes over my head, but this Wiki entry explains that the "depth multiplexing" of VHS Hi-Fi is in a frequency range unused by the video signal.

I'm not sure if this is a good analogy, but I envision it a similar to the Sound On Sound technique used in audio recordings. If you disabled the erase head on a tape recorder, you could record over an existing recording and "layer" the sounds with the original track "below" the overdub.


"Hi-Fi audio system

Around 1984, JVC added Hi-Fi audio to VHS (model HR-D725U, in response to Betamax's introduction of Beta Hi-Fi.) Both VHS Hi-Fi and Betamax Hi-Fi delivered flat full-range frequency response (20 Hz to 20 kHz), excellent 70 dB signal-to-noise ratio (in consumer space, second only to the compact disc), dynamic range of 90 dB, and professional audio-grade channel separation (more than 70 dB). VHS Hi-Fi audio is achieved by using audio frequency modulation (AFM), modulating the two stereo channels (L, R) on two different frequency-modulated carriers and embedding the combined modulated audio signal pair into the video signal. To avoid crosstalk and interference from the primary video carrier, VHS's implementation of AFM relied on a form of magnetic recording called depth multiplexing. The modulated audio carrier pair was placed in the hitherto-unused frequency range between the luminance and the color carrier (below 1.6 MHz), and recorded first. Subsequently, the video head erases and re-records the video signal (combined luminance and color signal) over the same tape surface, but the video signal's higher center frequency results in a shallower magnetization of the tape, allowing both the video and residual AFM audio signal to coexist on tape. (PAL versions of Beta Hi-Fi use this same technique). During playback, VHS Hi-Fi recovers the depth-recorded AFM signal by subtracting the audio head's signal (which contains the AFM signal contaminated by a weak image of the video signal) from the video head's signal (which contains only the video signal), then demodulates the left and right audio channels from their respective frequency carriers. The end result of the complex process was audio of high fidelity, which was uniformly solid across all tape-speeds (EP, LP or SP.) Since JVC had gone through the complexity of ensuring Hi-Fi's backward compatibility with non-Hi-Fi VCRs, virtually all studio home video releases produced after this time contained Hi-Fi audio tracks, in addition to the linear audio track. Under normal circumstances, all Hi-Fi VHS VCRs will record Hi-Fi and linear audio simultaneously to ensure compatibility with VCRs without Hi-Fi playback, though only early high-end Hi-Fi machines provided linear stereo compatibility."

Besides contact printing, there were also VHS duplicator VCRs with auto-loading mechanisms on them (for presumably cheaper/lower volume stuff).

I don't see how the tapes were automatically loaded, but it brought back memories of the Betamax changers which could hold multiple tapes and automatically change them when done playing/recording.

https://www.google.com/url?sa=i&url=...AAAAAdAAAAABAO

I had the AG-300 (Japan/US version of the model shown above and it was a thing of beauty (though really noisy!) in action!