Audio Quality - Network VTRs - 1970s
 

On late night TV (USA) there are usually several
infomercials (Time/LIFE typically) advertising
compilations of, for example, Soul Music that was
featured on The Midnight Special (NBC 1972-81).

The sound quality is fairly good, I know that audio
can be enhanced, but, AFAIK, audio quality was
not a priority on (Network) "QUAD" VTRs.

I'm wondering why the audio sounds so good from
these old "QUAD" VTR tapes?


Kirk Bayne

1) computer noise reduction processing?
2) your ears are older?

If it was taped in the source studio and not after reaching that far end of a POTS network audio link that may help too.

Back then most sets didn't have Hi.-Fi. speakers, so probably audio wasn't such a big interest <=> not poor sound, but not the best either.

Worked with servicing quad VTRs for decades. Signal to noise was limited by transverse oriented oxide (until 3M 8250 High Audio stock came out), and pre-distortion correction circuitry wasn't in place in earlier machines, but frequency response was quite good, wide band and typically similar to broadcast audio decks of that era. Viewers in the major markets of NYC and LA heard GREAT audio at home from quads. The rest of the country? Not so much, due to the horrendous limitations of AT&T long lines audio in those days. Most studio master quad tapes contain surprisingly good quality sound.

I remember the switch over from telephone audio to microwave audio in 1968. Wow!

Whoops. I remember we still had telephone audio in 1977 where I worked. Audio didn't really improve till 1984 when stereo TV came out. The networks paid for the second channel into your facility. This is before satellite distribution.

Thanks, TVBeeGee

I know that wow and flutter can also be (mostly)
removed (IIRC, the bias signal is actually recorded
and can be used as a reference to remove small
speed variations) and the signal to noise ratio can
also be improved with post processing, but if the
frequency response is poor, then retrieving good
quality audio isn't possible.


Kirk Bayne