Stereo VCR plays some stereo tapes as mono

I have two stereo VCR'S connected. VCR 1 is an older Sears 2 head unit,
VCR 2 is a newer, 4-head unit. VCR 1 has the antenna going into its
coax connection, and is connected to the composite (i.e.
yellow/white/red) audio/video connections of VCR 2. VCR 2's composite
audio/video is output to the tv and stereo speakers. I have them set up
this way to take advantage of VCR 1's apparent greater sensitivity to
local broadcast channels, using one of those WalMart adjustable
antennas going into a 12db amplifier box.

Here's the odd thing - I get a great stereo image off the antenna -
i.e. antenna>amplifier>VCR1>VCR 2>receiver/speakers. I get a great
stereo image playing a tape in VCR 1 (again, going through VCR 2 before
hitting the speakers). However, playing a broadcast quality country
music video video (made for tv station broadcast) that sounds big as a
house when played in VCR 1, obviously is coming out mono from VCR 2.

ovalking...

When I play some tapes in a Panasonic NVM10 camcorder, I have to adjust
the tracking to get stereo. Don't know if you've tried this.

VCR 2 *does* play other tapes in stereo, no problem.

Why would this be? When played in VCR 1, the signal has to go through
VCR 2 to get to the speakers, so why would VCR 2 not play this
particular video in stereo? Is there more than one kind of stereo
signal on VHS tapes? I would have thought they'd all be standardized.

UCLAN...

There is Hi-Fi stereo, and there is linear stereo. The Hi-Fi stereo is
embedded with the video, while the linear stereo has it's own "lo-fi"
recording head (like a cassette deck) and is recorded in its own track.
Are these Hi-Fi or linear stereo recorded tapes? How are your AUDIO
SELECT switches set?

b...

if its a 2 head unit then it'll be linear stereo, not fm helical scan
hifi stereo like the newer unit. for hi fi stereo you need minimum 4
heads.

Doc...

Ah so. So, there *is* more than one variety of stereo.

Richard Crowley...

You didn't reveal the make/model of your VCRs, but if they
are typical consumer machines, the likelihood of them having
linear stereo heads ranges from slim to none. Only a few pro
VHS VCRs had linear stereo that I have ever seen.

UCLAN...

The fact that his old 2-head (non Hi-Fi) VCR was stereo is in
opposition to this statement.

Looks like VCR #1 was playing back a stereo linear track, while
his newer 4-head VCR #2 played this track in mono. Only way I
can see this happening.

Richard Crowley...

I've seen marginal interchange problems cause the embedded FM
"Hi-Fi" recovery to fail when it would still reproduce the picture.
The fail-over is to use the mono linear track. (Or the stereo linear

blackburst...

2-head VCRs CAN include HiFi audio. 4 heads are not necessary for HiFi.

b...

no they can't. At least not in vhs.

blackburst...

Yes they can. I own a 2-head Emerson HiFi. In place of the 4-heads, it
has a digital processor for slomo and stills. And it will even freeze
incoming video!

4 heads are not necessary for HiFi.

In VHS yes.

The 2 extra heads are for stable slomo and stills.

b...

in mono vcrs, yes.

blackburst...

My understanding is: That is their sole use, when billed as "4-head".

I think the giveaway is the Dolby switch on VCR 2. Why would a HiFi VCR
have one? As I recall, nearly all of the linear stereo decks had Dolby

b...

It wouldn't and they don't.

Malcolm Knight...

Apart from my JVC S622 machine sitting beside me.

-b.

B.

UCLAN...

Yes. As I said, why would a hi-fi VCR, 2- or 4-head, bother with
Dolby linear stereo? None did, IIRC. Can you think of any?

blackburst...

I think Doc said VCR 1 was HiFi, VCR 2 just said stereo with a Dolby
switch. If VCR 2 was linear stereo as I think, that would explain his
problem: His tape from VCR 1 has HiFi tracks, but VCR 2 can't play
them. VCR 2 can only see the linear mono track.

UCLAN...

OK, don't answer my question. I think "Doc" already realizes that
his trouble is the linear/hi-fi dilemma.

Richard Crowley...

Only a few professional VHS machines had linear stereo.

ovalking...

I'd be interested to know if this includes the M1000 and the earlier B(?)
(it's in the loft) which I have.

David McCall...

I came in late here, so this might be redundant.

UCLAN...

So did he. This thread ended in February.

Sound was handled several different ways on different machines.

There were 2 kinds of audio tracks.

There was a linear track that was recorded in the same way
as a typical audio cassette. Simple magnetic heads recording
a linear track along the edge of the tape. It started as mono,
but later professional machines got stereo, and even later
consumers got it in some machines. Being that it was linear,
and the speed of the tape was rather slow, the frequency
response wasn't that great nor were the noise figures.

There was also what was called stereo "Hi-Fi" audio. This
was recorded by embedding the audio in with the video.
the audio quality was much better than the linear track,
especially since most VHS decks had been mono up to
that point. IIRC many, perhaps most, of the consumer machines
that were built with the "Hi-Fi" feature, still had mono linear tracks.

Because the "Hi-Fi" was embedded in the video, you couldn't
alter it without altering the video at the same time. However
the linear audio could be edited separate from the video.

Many decks had switches or menu items to allow you to choose
which tracks you wanted to listen to. Even if the tape was "stereo"
the linear track might have been mono. If you were listening to
the linear track you would then hear mono, but if you switched to
the "Hi-Fi" tracks, then you would get stereo.

Of course there could be other issues. If adjusting tracking
affected the sound, then you would be listening to the "Hi-Fi"
audio track.

Thanks, Gary

I've never seen a consumer VHS VCR with linear stereo.

Greg Melton...

I had a consumer VHS in the 80s with linear stereo. I remember
watching Purple Rain with it hooked through the stereo. Woo Hoo!

UCLAN...

Early model Mitsubishi SVHS (consumer models) VCRs had linear stereo.
But all late model standard VHS VCRs are linear mono.

Many Beta VCRs had linear stereo.

steveroberts...

Oh, there were lots around in the budget market in the late eighties.
I had a Hinari one which had linear stereo. I suspect they were trying
to cash in on people not knowing the difference between 'stereo' and
'hi-fi' tracks...

Steve

The Doctor Who Restoration Team Website
http://www.restoration-team.co.uk

Kimba W. Lion...

They exist(ed). There were a lot of commercial tapes with linear stereo
tracks before the engineers figured out how to kluge HiFi sound into VHS.

track played with a single-gap head, rendering it monaural.)

-B.

Richard Crowley...

They are. But if there is any interchange problem between
the two VCRs, it might not be bad enough to see on the screen,
but it may be bad enough for the VCR to abandon trying to read
the FM stereo tracks, and fail-over to the mono linear track.