Topic: Sony PCM-F1/Betamax "Beta HiFi" Digital Question

[mfrench]

OK,.... I've got a radio engineer that is insisting that the Sony PCM-F1/Betamax, PCM-F1 Beta HiFi tapes are not of a true PCM digital lineage.

Have I been confused for these past 30+years?

thanks

[larrysellers]

In what sense m0k3? Is he talking about analog audio written to a beta tape using a hifi beta recorder (removing the pcm converter box)?

[H₂O]

maybe it's the 44.056Khz of US NTSC betamax vs 44.1Khz of EU PAL betamax?

Meaning you transfer a tape recorded in NTSC using a PCM-601esd with SPDIF out then you maybe slightly upsampling the freq from 44.056 to 44.1 - or possibly the transfer will produce a result that will be ever so slightly fast.  I don't know what the US version of the 601esd does if anything when dealing with NTSC signals to output at 44.1 or 44.056.

Also unfortunately ALOT of transfers of BETA tapes people didn't use 601esd's and had to insert a D > A > D gap in the middle - 501 > analog > DAT or 501 > Analog > CDR.
Here is a Grace dead show transfered in the digital domain:
https://archive.org/details/gd1987-05-02.schoeps.grace.gems.105509.flac16


PCM-601esd is the only PCM box that has SPDIF on it by default - allowing for a digital transfer of a PCM/Beta tape to more modern recorders - there are modded 701's with SPDIF added.

Maybe DSatz or others have more insite.

[rocksuitcase]

I'd go with the above as most of the explanation. My buddy who used to do this (Poolside Studios, SF CA)and get paid for it usually mixed down from the Beta tapes on his MAC DAW, so does that make it "analog" by using the tape as the source? Not sure, but maybe what the radio guy is thinking?
Edit to add, this was the late 1980's when he used this setup.

[Life In Rewind]

I always wondered if "F1" was a genealogical analogy?

[mfrench]

What I meant was the lineage:
Digital F1 -> Analog tape capture master
then for playback and transfers....
Analog tape -> Digital processor for playback?
For some reason, my brain has released me from having to store this brain file, from 30 years back.  In my mind, I had it as straight DDD.
But in thinking it thru, now it seems like it is F1-> Analog capture // Analog recording -> F1 processor 16.44 output -> DAT 1644, as the most common transfer lineage.

[H₂O]

What I meant was the lineage:
Digital F1 -> Analog tape capture master
then for playback and transfers....
Analog tape -> Digital processor for playback?
For some reason, my brain has released me from having to store this brain file, from 30 years back.  In my mind, I had it as straight DDD.
But in thinking it thru, now it seems like it is F1-> Analog capture // Analog recording -> F1 processor 16.44 output -> DAT 1644, as the most common transfer lineage.

F1 > DAT is only possible using Analog out's of the F1 to Analog in's of a DAT recorder

So in this case you would have an Analog generation in the middle and it would not be a pure Digital clone

F1 can output analog or video out for digital (typically to a betamax deck such as the companion sony SL-2000) but going analog out for a master off an F1 doen't make a whole lot of sense.

Recording lineage would Typically be:
mic's > Pre > PCM-F1 > SL-2000 (betamax deck)  (it would be recorded in digital format onto a Betamax tape)

transfer example would be
Betamax deck (digital recording) > PCM-F1 > Analog > DAT
or pure digital
Betamax deck (digital recording) > PCM-601esd > SPDIF > DAT (you may need a deck that supports 44.056khz)

[Jonmac]

The F1 converts the analogue audio into a digital format, and then converts it again into a monochrome video format using black and white blocks to represent the 1's and 0's.
The video signal is then fed into the Betamax recorder, and recorded as analogue video, so it isn't a true digital recording format.

DAT recorders work in the same way but with an integrated transport mechanism.

[H₂O]

The F1 converts the analogue audio into a digital format, and then converts it again into a monochrome video format using black and white blocks to represent the 1's and 0's.
The video signal is then fed into the Betamax recorder, and recorded as analogue video, so it isn't a true digital recording format.

DAT recorders work in the same way but with an integrated transport mechanism.

True that the underling format is analog - but if you go down to that level almost ALL recording formats or transmissions are encoded into the analog realm and then interpreted as digital by various decoding mechanisms.   

I would think RAM based technologies would be true digital but anything on magnetic storage or transmitted on a wire over distance would be analog.

So the the word "true" would be in the eye of the beholder and how scientific you would want to get  - for the general discussion here PCM and DAT would be "true" digital formats where the sound is converted into a digital format then stored on encoded magnetic media and can be played back as a theortically as a clone of the original PCM stream.

 

[datbrad]

I think the engineer may be referencing the fact that standard settings on the F1 were 14bit pcm and were used that way quite a lot. Also, PAL video recorders were used to get to 44.1, NTSC video only went to 44.06 or something. I remember the guys using these in the '83-'88 period prior to DAT saying digital transfers to DAT were often not possible and required analog playback to transfer.

[datbrad]

Just found this data sheet:
Betamax PALsite: PCM-F1 : Specifications http://www.palsite.com/pcmf1spec.html

[DSatz]

> I've got a radio engineer that is insisting that the Sony PCM-F1/Betamax, PCM-F1 Beta HiFi tapes are not of a true PCM digital lineage.

Unless your radio engineer cares to explain exactly what his/her point is, the statement doesn't make any particular, obvious sense. You can view an F1 tape on a video monitor, and see the columns of black and white dots that represent the 0s and 1s. They're the (strategically interleaved, parity- and ECC-supplemented) output of the unit's analog-to-digital converter.

I mean, there is a certain theoretical level on which all digital recording is ultimately analog, along with all digital logic circuits of any kind, since signals are continuous and the transitions between the high and low (1 and 0) voltage levels are never perfectly instantaneous. In a sense, the "digitalness" of a recording (as with any logic circuit) lies in the way those signal levels are interpreted. And yet there is another, even deeper theoretical level on which all analog recording, or other signaling, is ultimately digital, because of quantum mechanics.

But if that's the level your radio engineer is thinking on, then it's not really about the PCM-F1, is it?

For that matter, the Sony and JVC professional systems throughout the 1980s also used "pseudo-video" signals, since video recorders with adequate bandwidth (and almost adequate reliability) were readily available items that didn't need to be invented. The only serious competing system at the time, Thomas Stockham's "Soundstream" system, used digital instrumentation recorders as its storage device--but the differences in principle are rather small.

--best regards

[John Willett]

I would guess your radio engineer is confusing the PCM-F1 system to the FM audio video tracks that some people used.

The PCM-F1 was a true 16-bit 44.1kHz system (in the UK anyway).

Although the PCM-F1 did not have a digital out as standard, the PCM-F1 series converters could be modified to have a digital ouput that you could connect to a computer or DAT.  Audio~Design in the UK used to do special modifications and HHB's CLUE system meant you could do editing with a couple of C9 transports slaved to the CLUE system.

I used this for about 10 years in teh 1980s before I bought my Fostex D10 DAT machines in teh early 1990s.