PCM–Sound, DAV and Audio Dubbing:
As mentioned already in the history chapter, the developers of the Video8 standard designed it in that way, that audio dubbing could be enabled without having to delete the original soundtrack. The method of choice was PCM, a standard digitizing technology developed by the professional audio industry of the 1970ies. Of course the option of dubbing and multi PCM was a special feature, offered only by expensive camcorders and Video8 VCR’s. Most other camcorders, however, did not offer that option.
PCM dubbing means that a stereo sound is recorded. With that option Sony overcame a technical problem of Video8, which was solved only by 1989, when the first devices with polarized FM-Stereo were put on the market. Only the two high priced PCM recorders EV-S1000 and EV-S9000 were equipped with audio dubbing and/or recording in PCM Stereo. By standard these two VCR’s record in both modes at one time, meaning that after having done a recording, one could switch between the polarized HiFi-Stereo and the PCM-Stereo. The latter could be lifted or downgraded with level meters, as desired. Both VCR’s also offer the option of mixed playback, which in the original recording always produces a little echo, as the digital PCM sound takes a distinct very short time for being digitized. This mixed setting was offered especially for a fast way of dubbing, where a PCM sound was just added as a background music to the original sound. Only model EV-S9000 offers a special feature, where the original HiFi sound may be suppressed with a level meter while mixing it with the PCM sound.
For an optimized dubbing the original sound will have to be stored on a different media and should be re-recorded in a synchroneous way by mixing it with a dubbing sound and finally store this dubbed sound on the dubbing track of the video. This is yet another of the many advantages of Video8 versus VHS: at VHS audio dubbing may only take place on the border mono audio track. If the original recording was done in mono, the original sound is lost after the dubbing process. Only when the original recording took place via the fm-stereo track, it may be regained from the same source, however while recomposing it and thereafter dubbing the video, the stereo sound is transformed to a mono sound with a very poor sound quality.
A very nice speciality of Video8 was offered but in the first 4 years from 1986 to 1990 with the Multi PCM technology, which was developed only for Video8. This 6-track system on one Video8 tape was also named the “Multi Audio PCM” with a special DAV logo on the 4 existing models EV-S 600, EV-S-700, EV-S650 and EV-S850. DAV means Digital Audio Video. Indeed these Video8 recorders were capable of recording up to 6 by 4 hours, equalling 24 hours of digital stereo sound on a tiny P5-120 cassette.
By 1990, however, Sony stopped that DAV technology. Since that time only a sigle track (the lowest track no. 1) was utilized for audio recording. It seems to me, that at that time Sony just wanted to sell more Video cassettes, because with that old DAV-system, one V8 cassette was able to save as much as 6 cassettes with the newer system. Those days V8 cassettes had a price of about 15Eur per cassette! The coming PCM-models were only capable of the one-track PCM, which for some strange reason was not even compatible with the first track of multi PCM. Only the dubbing PCM sound is compatible with that of the newer models. Also by changing the standard, the old indexing system for marking up to 99 points on a cassette was no more compatible with the newer indexing of the S1000 and the S9000.
To get a better understanding of these changes, it may be remembered for the sake of Sony, that all this has to do with the fact, that in the first 4 years of Video8 there was no good access to good stereo sound. PCM was the only solution, as the polarized fm-stereo sound was not yet ready for the market. Also one should not forget, that at that time the common mono sound of VHS was far beyond good and evil, as compared to the standard hifi mono sound of Video8! Additionally Sony and all the Video8 licensees saw a chance to add speed to the technological givens of camcorders at that time by finally offering stereo sound to their newest developments. Because of comparatively small production lines of the many Video8 models and the faster growing pace in new miniaturizing techniques, several mistakes were happening in several models with regard to durability of the mechanics and of some electronical components, shortening the lifetime of not serviced or wrong stored camcorders. So new models were a good solution to let the consumer switch to a better model.