Hi-Fi audio makes a slight fuzzing and chirping in the right channel
 

I found a problem on my "new" Hi-Fi vcr (Panasonic NV-FS88). The audio seems to be mistracking? by making a slight chirping and fluttering noise on the right channel for a lot of tapes, but some tapes are fine. The tapes that make the chirping play back without the noise on other hifi vcrs.

I looked in the service manual https://anonfiles.com/4dD9m77cz0/pan...8eg_vcr_sm_pdf and found these at the page 23-24: 2-3-27. Hi-Fi AUDIO CARRIER FREQUENCY ADJUSTMENT & 2-3-29. FM BPF LEVEL ADJUSTMENT.

Is one of these meant to fix the problem? I don't know a lot about electronic, but I'm willing to carefully try and fix it, as if it fixes the chirping, even a little bit, that'll be a worth improvement, as I want to capture as close to the source without any artifacts. But I only need to know which of the instructions is meant for the problem, to not break something else, and hoped maybe someone knows this.

I have tried two things already: adjusting roller guides and manual tracking. Both only changed the rumble loudness.

Thanks in advance.

Small question: Is there an azimuth adjustment for the hifi heads? I read somewhere that there should be one, but it may be wrong.

You should not have messed with P guides, Now you lost the factory alignment.
No there is no hifi azimuth adjustment but you can tweak the head switch point if the drum motor stator is on the top.

I adjusted them so there was the least amount of 50hz rumble in hifi and in hopes that the chriping would stop, but it didn't sadly. Capturing Hi-Fi sound for me is a higher priority than video and the video and standard audio head quality didn't change after adjusting (recapture-compared), so it's all good.

I was talking about the guides around the video head, If you messed with those you can't get them back exactly the way they were. AC head for linear audio has nothing to do with HiFi audio.

I adjusted these (supply side roller guide & takeup side roller guide): https://www.repairfaq.org/sam/vcrxprt.gif

Yep, that's what I meant, make sure other tapes play fine, miss adjustment is not always visible with good tapes but some weak tapes will exhibit some miss tracking issues.

I tried other tapes, and they played just as well, but I'll keep this in mind, Thanks!

But I hope someone can answer me about the hi-fi mistracking too :/

If other hifi tapes play well then i guess the problem reside in the tape not the heads or alignment imo

Before altering a P guide height I mark the original positions with a felt pen. Perhaps take a photo of these marks on each guide. Also sometimes the picture tracking and Hifi tracking dont quite coincide. Try manually adjusting the tracking usually with the channel buttons on the remote in play mode.

Moderate HiFi clicking can often be lessened with a modern Declick tool in a digital audio editor. Often these days you can purchase audio restoration plugins and they will appear your video editing program audio effects list.

Your sample at just over 2 seconds is very short. I can only find two clicks just after 1.2 seconds, in the right channel. I Declicked the file as below. You'll notice the two clicks have been removed.

It's hard to tell if the other general background noise is due to a fault in your HiFi playback or is inherent to the program itself. Also since you seem to have increased gain it's hard to know what is the highest recorded peak level in the complete program. Better to "peak normalize" the entire recording then upload a shorter sample from that peak normalized file, perhaps 10 seconds worth, obviously including if possible a longer section of relative silence than you have here.

The hifi audio from the same tapes play well on other vcrs, but not on this one. All the tapes that have hifi audio have fluttering on the right channel in this vcr + the mistracking crackle is much louder on the right than on left channel too, meaning something isn't aligning properly, i think.

Manual tracking or the roller guide adjustment made no difference in the chriping sound, or just made it even louder with HIFI crackling=mistracking.

What is this specific declicker you use? It seems to have removed the clicks without altering the sound quality, this is pretty nice!

But this is not the main problem. I've faced these crackles/clicks from hifi, and can remove each by hand (although would be obviously nice to have a good declicker tool which does it automatically). If you open the audio in audacity or some other software that shows spectrogram, you can see how there's something wrong with the right channel and it sounds like "trtr" or "pfpfp" - chirping, i don't know how to explain it, just have to listen to the right speaker.

I uploaded another sample to hear it better and the gain isn't altered. But even if you turn up like 10dB, you can hear the chirping starting at 5 seconds in the new sample.

I'm sure this is a vcr problem.

I used Izotope RX Declick here but there are many such audio declick tools these days. The first digital audio declicker was used professionally on sound discs in the late 1980's! Here's a link to a promo video from 1989. https://youtu.be/9L5HxkSgoUM

They sound like standard clicks to me. You can hear the result below.

Some occasional random clicks with HiFi sound seem inevitable. Trawling through a 3 hour program to manually remove them is impractical and unnecessary when it can be done automatically with the correct tool.

I've tried izotope rx specifically to declick/crackle some samples, but i really dislike how it makes the voices sound muffled. It removes those crackles, but ruins the other parts of the audio as well. It's not that difficult to remove the cracks manually, you just have to have patience, and the results are the best you can get :cool:

-----

I attached an image of a spectrogram. This is what the chriping sound I meant. I'm not talking about the crackles that izotope can remove, but the sounds i circled in red. If you want to hear the chirping, turn the gain up a bit and listen to the quiet part in the sample.

It sounds like crickets chirping on the right.

I only used a declicker. Clicks and crackles are not the same. The tools are also different. Not all clicks can be removed. The various audio restoration tools are not equally effective. It takes time and experience to learn the strengths and limitations of each tool on various audio problems. Why not upload the voice example you mention. Also the chirping sound. A sound file is so much more useful than a spectrogram. Anyone with an audio editor can make their own spectrogram from it but not the other way around.

I took the spectrogram from smpl.wav I uploaded just to visualise it.
Is it possible to change something in vcr's hardware to take out the crickets of the right channel? I am willing to take the risk of breaking something, because I really want to know what is causing this, and also maybe someone else could also fix the problem themselves, if they notice this.

These stitching solutions are not the way to resolve problems, They are time consuming to say the least. It is better to fix the problem at the source. I see these suggestions pop up every time someone posts about a VCR mechanical problem.

I agree, the source problems should be fixed first, if possible, and now I cannot decide if I should capture with the chirping, or to find a fix for it, but I just cannot find any documentation about hifi tracking adjustment or something else that fixes this :depressed:

I understand now. I only heard the clicking. Missed the "chirping" sound. If the chirping seems to be only with that VCR and you want to capture both picture and HiFi sound on it then yes it would be ideal to have the VCR problem fixed. Having said that, on this forum sometimes members suggest capturing picture and sound on separate VCR's and then matching them together in the NLE.

Incidentally, I wouldnt expect either a declick or a decrackle to address the chirping sound. They're not designed for that type of sound.