Strange digital noises on capturing linear audio VHS tapes

[Originalsboy]

As the name implies, I've noticed on my Panasonic Omnivision VCRs (the PV-9450, PV-9451, and PV-9662) whenever I play mono/linear audio tapes, I have this horrible sounding audio that sounds kinda scratchy (for a lack of a better term). Strange part is, Hi-Fi audio tapes are not affected by this. I also have other VCRs, like a JVC HR-DVS3U which seems to not have this particular problem.

EDIT:
I did try the following to no result:
Switched audio cables
Put them on a grounded power strips
Verified it wasn't the room that I'm in's light bulb causing the issue (its florescent)
Adjusted the linear audio heads on all

[cholla]

I will leave it to the VHS/VCR experts for the tape & audio head adjustments.

I just wanted to say I doubt it is a grounding problem.
Even if it was unless you live in a house;you probably couldn't correct it.
To explain simply an electrical system needs to go to a single ground at the service panel.
All the outlets need to connect to this ground in the service panel.
Having more than one ground is what usually causes problems.

[themaster1]

Do an experiment, take a big copper wire (the kind that stays bent) touch the top of the audio/control head and touch the chassis, see if it improves.

[timtape]

As the name implies, I've noticed on my Panasonic Omnivision VCRs (the PV-9450, PV-9451, and PV-9662) whenever I play mono/linear audio tapes, I have this horrible sounding audio that sounds kinda scratchy (for a lack of a better term).

Rather than digital noise it sounds analog to my ears.

There's a lot of hiss there but the noise could be normal with the real problem a weak signal.
Do all linear audio soundtracks sound just like this? If it sounds the same on all three Pana players that seems a rare coincidence, unless it is some outside interference.

What is your audio signal chain setup? What other equipment does the audio signal pass through after the VCR?

Strange part is, Hi-Fi audio tapes are not affected by this. I also have other VCRs, like a JVC HR-DVS3U which seems to not have this particular problem.

Linear audio has less fidelity than HiFi obviously so nothing strange about that as such, but normally there will be much less noise than your example while still noisier than HiFi.

Adjusted the linear audio heads on all

Few people really know how to adjust them, especially these days. Do you? Some adjustments like head zenith (front and rear height) require a special jig or technique to get it right. It's possible the heads are dirty, worn, misaligned, or a combination of those.

[Originalsboy]

As the name implies, I've noticed on my Panasonic Omnivision VCRs (the PV-9450, PV-9451, and PV-9662) whenever I play mono/linear audio tapes, I have this horrible sounding audio that sounds kinda scratchy (for a lack of a better term).

Rather than digital noise it sounds analog to my ears.

There's a lot of hiss there but the noise could be normal with the real problem a weak signal.
Do all linear audio soundtracks sound just like this? If it sounds the same on all three Pana players that seems a rare coincidence, unless it is some outside interference.

What is your audio signal chain setup? What other equipment does the audio signal pass through after the VCR?
I was expecting some audio hiss, since that tape was recorded in SLP mode. To answer your question, it happens on all linear audio tapes, SP, LP and SLP recorded ones, although SLP recorded tapes is the one I noticed it the most on. Audio chain is just the VCR's audio output be connected directly to one of my capture cards (a WinTV HVR-950, Pinnacle 510 and 710).

Strange part is, Hi-Fi audio tapes are not affected by this. I also have other VCRs, like a JVC HR-DVS3U which seems to not have this particular problem.

Linear audio has less fidelity than HiFi obviously so nothing strange about that as such, but normally there will be much less noise than your example while still noisier than HiFi.

Adjusted the linear audio heads on all

Few people really know how to adjust them, especially these days. Do you? Some adjustments like head zenith (front and rear height) require a special jig or technique to get it right. It's possible the heads are dirty, worn, misaligned, or a combination of those.

The extent that I have done to the linear audio head was basically taking a screwdriver and adjusting the head, using this video here as a guide (and doing some tinkering on my own):
https://youtu.be/fazLIPQqKLk?si=9OleKxigvHkyam-j

[Originalsboy]

Do an experiment, take a big copper wire (the kind that stays bent) touch the top of the audio/control head and touch the chassis, see if it improves.

Interesting, I'll have to look for some copper wire and try that.

[timtape]

As the name implies, I've noticed on my Panasonic Omnivision VCRs (the PV-9450, PV-9451, and PV-9662) whenever I play mono/linear audio tapes, I have this horrible sounding audio that sounds kinda scratchy (for a lack of a better term).

Rather than digital noise it sounds analog to my ears.

There's a lot of hiss there but the noise could be normal with the real problem a weak signal.
Do all linear audio soundtracks sound just like this? If it sounds the same on all three Pana players that seems a rare coincidence, unless it is some outside interference.

What is your audio signal chain setup? What other equipment does the audio signal pass through after the VCR?
I was expecting some audio hiss, since that tape was recorded in SLP mode. To answer your question, it happens on all linear audio tapes, SP, LP and SLP recorded ones, although SLP recorded tapes is the one I noticed it the most on. Audio chain is just the VCR's audio output be connected directly to one of my capture cards (a WinTV HVR-950, Pinnacle 510 and 710).

Strange part is, Hi-Fi audio tapes are not affected by this. I also have other VCRs, like a JVC HR-DVS3U which seems to not have this particular problem.

Linear audio has less fidelity than HiFi obviously so nothing strange about that as such, but normally there will be much less noise than your example while still noisier than HiFi.

Adjusted the linear audio heads on all

Few people really know how to adjust them, especially these days. Do you? Some adjustments like head zenith (front and rear height) require a special jig or technique to get it right. It's possible the heads are dirty, worn, misaligned, or a combination of those.

The extent that I have done to the linear audio head was basically taking a screwdriver and adjusting the head, using this video here as a guide (and doing some tinkering on my own):
https://youtu.be/fazLIPQqKLk?si=9OleKxigvHkyam-j

I thought you might have seen that video. Unfortunately it oversimplifies the process. He doesnt explain step -by -step what he's doing and why. It looks more like a party trick.

[GAhere]

Analog audio and control tracks are done on the same head, the tracks are side by side below the video.

While it is possible to adjust the audio/control head to compensate some, chances are the deck that originally recorded the tape had some alignment/adjustment issues and that is the way the tape is..

Did you try the tape on a different deck and get same results? If the same results then it is the tape and the only way to correct it is to now make your deck out of alignment..

It should also be noted, non HiFI "stereo" decks also used the analog audio head on the control head, this required splitting the mono analog track in half (just like mono/stereo audio cassettes) so now alignment gets even more critical. You also get more tape noise and less audio quality/bandwidth with analog non HIFI tracks.

HIFI VHS audio tracks are recorded in the video heads fields..

[timtape]

It should also be noted, non HiFI "stereo" decks also used the analog audio head on the control head, this required splitting the mono analog track in half (just like mono/stereo audio cassettes) so now alignment gets even more critical. You also get more tape noise and less audio quality/bandwidth with analog non HIFI tracks...

Yes more critical in some aspects such as head height, and tape damage, which often starts first on the very edge of the tape where the left channel is situated. But the narrower stereo tracks were less critical for head azimuth alignment with its loss of higher frequencies.

To compensate for the narrower and now noisier stereo linear tracks, Dolby B noise reduction was introduced. With Dolby B the tracks were now quieter than the mono track without it, but Dolby B itself was quite sensitive to even slight record/playback errors so was a mixed blessing.