Audio Muffled on Certain Tapes on JVC but Sounds Fine on Other VCR

[bbmaster123]

[Attachment 58480 - Click to enlarge]Is my jvc possibly defaulting to linear audio?

On certain tapes the jvc sounds fine, on others its muffled. Those same tapes that are muffled sound MUCH better on my vcr/dvd combo, even though the video doesn't match the jvc image quality.

As for the tapes that sound fine on the jvc, they sound pretty much identical on the combo unit, maybe sliiiiightly brighter.

Would this be caused by poor hi-fi tracking? I tried norm/mix as well as routing the audio through the combo and going direct, but same results. I also tried manual tracking adjustment but as I expected it only affected the video.

quick refresher of my capture chain:
jvc --> vcr/dvd combo --> ATI AIW USB 2.0/Asus Xonar Essence STX --> Vista 32bit --> Virtualdub huffyuv

I was thinking to try opening the jvc and clean the heads + interior but if it sounds fine on some tapes, that's probably not the issue, eh?

I've attached an image showing my results of the same tape captured on both vcr's. As you can see, it looks like the jvc mostly cuts off around 4-4.5khz, what looks like a filtered band around 4.5-6khz, some sibilance in the 6-10khz range, and a steep low pass shelf/cut about 14khz+

I didn't want to have to do so much recapturing with so much else to get to, but it is what it is I guess.
Thanks for any insight, happy to provide more info if needed!

[orsetto]

None of the "premium" VCRs recommended for VHS capture are 100% perfect: each brand and model range has flaws, which is why we're often stuck with a shelf of several different VCRs to suit different tapes. One of the known JVC issues is variable audio performance: their HiFi tracking lock isn't very stable on a depressing number of older tapes, if a JVC can't solidly lock on a drifty HiFi signal it will default to the linear sound track on the tape edge. And the aggravation doesn't stop there: some later-model JVCs have noticeably worse than average playback quality of the linear audio track (more muffling, hum and noise than most other VCRs).

The VHS HiFi audio system is inherently unstable and unreliable: many many VCRs have difficulty keeping a consistent tracking lock on HiFi tapes they did not record themselves, and some brands of VCR have a nominal HiFi tracking alignment that veers way off from others (i.e., JVCs are not too fond of playing HiFi tapes made on Hitachi/RCA and several Panasonics, Panasonic doesn't track JVC HiFi too great, and Hitachi is all over the place as a player). Depending on the specific tape and VCR, the unit may have so much difficulty tracking the HiFi that it won't lock at all, defaulting to the linear audio. In such cases, one then needs to prioritize the JVC video enhancements vs cleaner linear audio performance of another VCR. The more ambitious among us might do two passes: a JVC for the video, another VCR for the audio, then combine and adjust the two in software post-capture.

It is possible the tapes you're having difficulty with are not HiFi at all, so no HiFi track is available no matter the VCR. All you can do is use whatever VCR in your arsenal has the best linear audio performance. If you're quite certain these tapes do have a HiFi track, you may need to try several HiFi decks before finding one that locks on the HiFi with stability. Some HiFi tapes are very very resistant to stable tracking: they were recorded slightly off to begin with, then 10-20-30 years of aging shifted the physical tape dimensions slightly making it near impossible to get perfect HiFi without deliberately misaligning a VCR mechanism to match them.

VHS HiFi audio is among the more challenging aspects of capture. Its somewhat of a kludge that doesn't operate in logical expected fashion: its recorded by spinning heads on the video drum, but they are separate heads with their own tracking angle that is typically slightly off from the video head tracks. Very often you'll encounter a tape that has no or minimal video tracking issues (picture plays perfectly on multiple VCRs), but the HiFi audio will be maddeningly resistant to stable tracking lock (frequently needing a tracking setting that disturbs the video). Settling for the mono linear audio is sometimes the only expedient, practical alternative, so it is immensely frustrating that the otherwise well-designed JVCs have such dismal audio performance in linear mode (I'm appalled at how bad my SR-V101 and SR-MV50S sound in mono mode: an ancient Record-A-Call microcassette phone answering machine runs rings around them).

[bbmaster123]

I thought mixing the audio from one pass with the video from another always leads to sync issues, is this not always the case? I have no issue doing 2 passes and remuxing if it gets me the best audio with the best video, but I don't want to spend months or years resyncing ahaha

I don't know for sure that its hifi but it is mono, so that leads me to believe these tapes are linear. tracking doesn't shift throughout. however the disparity in sound fidelity is very obvious when played back, even if you apply an eq to approximate the difference in higher frequencies.

Another known good tape, which definitely has hifi audio, sounds perfectly ok.

[Brad]

If you do 2 captures, you can confirm whether they will sync by trimming them to the same starting frame. Then compare them near the end. If frame 600,000 (for example) is the same frame on both, you're good to go. (Provided each capture itself has solid AV sync.)

Properly TBC'd captures will have no problem synching.

Two raw-dog captures into Easycrap probably will not synch. (You're lucky if either of them individually does.)

I think your direct VCR caps into AIW USB2 are somewhere in between those two extremes, for stability.

[oln]

A dirty linear audio head can cause dulled sound/loss of higher freqs, though no idea if that's the issue. Misadjusted audio head azimuth (angle/tilt) on vcr or recording can also have an impact, tho that rarely goes out of alignment easily (compared to e.g tape guides). I guess it's possible that the head on the combo is less worn, or just reads the audio signal better. If there are hi-fi tracking isues you tend to get buzzing/crackling instead. Maybe it's just me but I've found JVCs to tend a bit towards sounding muffly rather than letting through higher freqs and more noise compared to other VCRs, but YMMV.

[bbmaster123]

thanks for the input everyone
hmmm...looks like I really only have 2 options, try to resync, or try to clean the linear heads in the jvc.
I'm going to try resyncing right now, just waiting for the capture to finish. Might try to clean it when its finished, and hope it helps

[bbmaster123]

well looks like the jvc is about 1 second slower over a 2 hour tape. So close. Individually, the audio matches each video, but not each other.
I can manually slide/stretch the audio around and try to get it to match, but thats also a lot of work for more than one tape, so I'm going to also try cleaning the linear heads tonight to hopefully avoid having to do all that.

In the meantime I'm also copying so miniDV tapes on a separate pc. SOOO glad those are easy :P

EDIT: So I cleaned it out. It was dirty, so I cleaned the important areas as well as the linear heads but it made only a small difference unfortunately.
I guess I'm going to have to resync audio for all the tapes that require it.

EDIT 2: Looks like resync is more difficult than just matching the start and endpoints as its drifting around, which is what I initially thought would happen. Am I out of options now? Other than spending a ridiculous amount of time trying to resync?

[bookemdano]

Are you using a frame TBC during the captures? If not, then that's what you need to get everything to match up.

[bbmaster123]

bookemdano
Re: Audio Muffled on Certain Tapes on JVC but Sounds Fine on Other VCR

Are you using a frame TBC during the captures? If not, then that's what you need to get everything to match up.

In LS words, its a TBC-ish. It does help a lot. Using S-video in and out, and rca in and out. So just to clarify:
JVC HR-S9500U--> TBC-ish --> ATI USB 2.0/Asus Xonar

This works well enough to keep audio in sync with video over a whole 2-3 hour tape (audio 1 matches video 1) but apparently not across captures (audio 1 doesn't match video 2).

Hope that makes sense.

Unfortunately a datavideo tbc costs way more than would be possible for me at the moment. I'm sure it would be the easiest way to go based off all the threads on this forum but in 2021 I guess they are pretty rare and pricey. I've seen only 3 close ish to me so far, $2500-$2800 CDN

I was debating checking the alignment of everything with a spare tape. Ofc if the linear audio head is off its going to sound bad, and I've never had the unit checked as I only got it a few months ago and it played hifi audio perfectly fine. When I opened the JVC other day, the only thing I did was clean the dust out.

[orsetto]

Have you tried a more automated audio-video syncing method like the one described in post #22 of this thread? Might get you somewhat closer to the mark with less work.

Otherwise, in solving this issue "all roads lead to financial ruin" (at least temporarily until you can resell the gear to recoup some of the outlay). Most of the popular, available, more recent JVC decks with TBC/DNR have utterly atrocious, muffled, noisy linear audio performance. Why exactly JVC chose to install beyond-crap linear audio circuits in otherwise high-performance machines is one of those infuriating corporate mysteries that make tape capture torturous today (second only to "why did Panasonic insist on mfg the AG1980 out of 8,453 failure-prone discrete components when every other VCR they made before and after that time period ran off a single board the size of a playing card that won't burn out even if you soak it in Ronsonol and drop a match on it?".

Anyway, if you can't hack the re-syncing of separate audio-video passes, the remaining options require spending cash. A frame TBC like DataVideo might help bring the two VCR passes in closer sync to start with, but I agree asking prices delivered to Canada are insane at the moment. Or you could buy a backup VCR that combines a TBC/DNR feature similar to JVC with better linear audio performance. Of which only two alternatives are available: Panasonic AG1980 or Mitsubishi HS-HD2000U. This would let you capture good audio and video in a single pass, but neither VCR is perfect:

The 1980 is crazy expensive now no matter how you approach buying one (fully restored already, or in as-is condition to be restored by a tech). But it does retain at least 50% of its value on resale, and in good working condition has more flexible tracking of video and HiFi than most JVCs, notably better linear audio playback, and roughly comparable TBC/DNR (slightly better and slightly worse depending on your criterion, IMO its a wash).

The Mitsu 2000 more or less gives you the same compromise as JVC (excellent noise reduction and line TBC but twitchy tracking with HiFi and EP video). It does however have cleaner linear audio and sells for lower prices than most popular JVC models. A Mitsu 2000 in good condition usually stays that way, but they've gone thru enough different owners now that you need to watch out for funky examples with bad loading mechanism.

An outlier worth considering for some people is the rare-ish Sony SVO-5800 or SVP-5600. These are large late-model professional studio VCRs with the absolute best linear audio playback I've ever heard, equally good HifI, very stable wide range tracking, and built-in full-strength modern frame TBC that eliminates the need for a DataVideo box. Disadvantage is cost usually approaches the Panasonic AG1980, they only play SP (two hour) tapes (no LP or EP), and DNR isn't at the level of JVC, Mitsu or 1980 (however colors are very clean and pure). Occasionally they pop up at fire sale prices in good condition: I snagged one for $200 last year that looked beat but works flawlessly. They seem to be scarce in North American NTSC guise, most for sale listings are European PAL versions.

[bbmaster123]

Have you tried a more automated audio-video syncing method like the one described in post #22 of this thread? Might get you somewhat closer to the mark with less work.

That looks like he's adjusting his video length to match his audio from the same capture. I don't think that would work, but thanks all the same

Why exactly JVC chose to install beyond-crap linear audio circuits in otherwise high-performance machines is one of those infuriating corporate mysteries that make tape capture torturous today

Oh are they actually just poor quality linear circuits? I was thinking it wasn't meant to sound that muffled. I will upload a short audio only sample after work along with the better quality audio for comparison. Now that I think about it, my older 3500u also had this issue, which is kind of where I started this journey a number of months back.

8,453 failure-prone discrete components

JEEEZ seriously? HA that's insane, even if they weren't failure prone components that's still a ton of additional complexity and lots of room for failure. WTH Panasonic? lol that's boggling

Of which only two alternatives are available: Panasonic AG1980 or Mitsubishi HS-HD2000U

I'll look around for both of those and the sony's you mentioned, but even finding my current JVC took a while, pretty scarce around here I guess. Heh, maybe I'll get lucky for once :P

I also suppose there's the 3rd inferior option of having two copies of each tape from each machine, but that kinda sucks as a "solution".

BTW has anyone ever done anything like an upgrade to the audio circuit? I assume each model has completely proprietary components, but just thought I'd ask.

thanks as always Orsetto

[bbmaster123]

I didn't line these up precisely, but here's about 10 seconds of audio from each machine. The only adjustment I made was I boosted the JVC by about 8db to match the combo/passthrough, the JVC has a much weaker signal on these tapes, but again the hifi is fine so those tapes are still ok.

If you boost the treble, the JVC audio gets very noisy, and still lacks the nuances, most obvious in the sibilant frequencies, that the combo picks up.

Let me know what you think. I'm still considering double checking the alignment. I haven't done that before on a vcr, but I'm pretty sure I can handle it, if it would for sure help.

[orsetto]

Let me know what you think. I'm still considering double checking the alignment. I haven't done that before on a vcr, but I'm pretty sure I can handle it, if it would for sure help.

Your samples are consistent with the differences I hear between the linear audio playback of my own JVCs vs other VCRs. Your tweaked example of your JVC is noticeably better than the unretouched linear audio I get out of either of my JVCs: I've never bothered trying to tweak them because they seemed so muffled and noisy that it wouldn't be worth the trouble. You've got me re-considering that option, although I do have the luxury of owning the Panasonic, Mitsu and Sony alternative VCRs. All four VCRs have comparable TBC/DNR performance, so when the JVC linear audio bites I just switch VCRs. But occasionally the JVC is distinctly preferable for video despite the lousy linear audio, so I might try tweaking it in post as you did.

I'd recommend against trying to adjust your JVC alignment: you risk more problems for no real potential improvement. The bad linear audio playback is baked into the design, similar across multiple models and mfg dates of JVC beginning some time in the 1990s. The JVCs I used in the mid to late 80s had very good linear audio, so its something JVC changed toward the end of the VHS era. Unfortunately thats when most of the popular JVC TBC/DNR models we rely on for capture were made.

[themaster1]

Try this trick (that worked for me in the past, once or twice)
1- enable b.e.s.t and edit mode, enable hifi audio
2- take your vhs tape and record something toward the end of your tape for about 1 minute, preferably in s-vhs mode ( so if your tape is vhs you're gonna have to fill the hole(s) underneath the shell with scotch or something, the vcr will think it's a s-vhs tape.
Then rewind all and see if you can get good hi fi audio playback

[bbmaster123]

Your samples are consistent with the differences I hear between the linear audio playback of my own JVCs vs other VCRs.

If that's how they came, right out of production, I honestly can't understand how they would think that is acceptable (besides profit ofc, I'm talking from a technical standpoint)

I'd recommend against trying to adjust your JVC alignment: you risk more problems for no real potential improvement

that's too bad, but at the same time a bit of a relief. If I don't stand to gain anything I wont bother.

I might try tweaking it in post as you did.

the jvc sample I uploaded only had the volume boosted, no other tweaking. I did play around tweaking that file, but I didn't save the changes since it was so noisy after raising the treble. Denoising gets rid of the noise, but since the signal is missing the upper frequencies anyway, it becomes even more obvious that there was a steep high-frequency signal roll-off to begin with.

themaster1

1- enable b.e.s.t and edit mode

I don't have BEST on my model, if I'm not mistaken that is only for European/PAL models? I did enable edit mode, but it didn't affect the sound.

2- take your vhs tape and record something toward the end of your tape for about 1 minute, preferably in s-vhs mode ( so if your tape is vhs you're gonna have to fill the hole(s) underneath the shell with scotch or something, the vcr will think it's a s-vhs tape.
Then rewind all and see if you can get good hi fi audio playback

I'm not 100% sure what you are suggesting here, sorry. Sounds like you're trying to get me to trick the vcr into thinking there's an s-vhs inside when its only a standard vhs tape to try to get it to use the hifi heads to read the linear track which almost but doesn't quite make sense, I think? Just to clarify, my hifi tapes sound about how I would expect them to on the JVC, no issue there. Could you please explain a bit more? And thank you for the suggestion

I did try swapping the vhs reels into an s-vhs cassette/shell, but playback was the exact same. I did that because the original casing was damaged an I had a spare blank

[orsetto]

If that's how they came, right out of production, I honestly can't understand how they would think that is acceptable (besides profit ofc, I'm talking from a technical standpoint)

It really is odd, because I can't imagine there's any cost saving profit motive involved: linear audio is such old inexpensive default backup tech, and JVC prides themselves as "inventor of VHS and the most quality-conscious VCR brand", and their earlier models had fine linear audio along with HiFi. I suppose one could rationalize from 1999-2007 when they were sold, HiFi was the long established newer standard, so hardly anyone wanting a premium SVHS deck would be playing old linear-only tapes in their fancy new JVC. Whatever the mfr reasoning (if any: maybe it was just a mistake), its an issue with some of the later JVC vcrs that we have to live with (or work around).

[oln]

Maybe JVC engineers got a bit too obsessed with avoiding tape hiss and put excessive low pass filtering on the linear audio? Their later VCRs tends to overdo noise reduction on video, so maybe they did the same for audio. Even my cheap late model Samsung and LG decks don't have this kind of muffled linear audio. (though the LG ones have annoying high-pitched whine instead.) The main processing ICs used in the later vcrs typically combined head amp, video decoding, linear audio and some switching (some jvcs also hi-fi audio). It seems the audio filter is often part or fully in discrete components next to the IC though, so maybe one could modify it to filter the highs less.

I don't have BEST on my model, if I'm not mistaken that is only for European/PAL models? I did enable edit mode, but it didn't affect the sound.

It's called Video Calibration on the US models. I don't see how it would affect audio though, especially not linear audio.

[bbmaster123]

Maybe JVC engineers got a bit too obsessed with avoiding tape hiss and put excessive low pass filtering on the linear audio? Their later VCRs tends to overdo noise reduction on video, so maybe they did the same for audio. Even my cheap late model Samsung and LG decks don't have this kind of muffled linear audio. (though the LG ones have annoying high-pitched whine instead.) The main processing ICs used in the later vcrs typically combined head amp, video decoding, linear audio and some switching (some jvcs also hi-fi audio). It seems the audio filter is often part or fully in discrete components next to the IC though, so maybe one could modify it to filter the highs less.

I don't have BEST on my model, if I'm not mistaken that is only for European/PAL models? I did enable edit mode, but it didn't affect the sound.

It's called Video Calibration on the US models. I don't see how it would affect audio though, especially not linear audio.

Yes I agree it very well could be over-filtered. I would prefer no filtering of course. if they are discreet components, it may be possible to bypass those by soldering rca cables directly, but who knows. I do have a working s3500u that sounds the same on these tapes, maybe I'll give it a shot and see what happens lol

Ah yes video calibration, I tried that too but didn't notice any difference whatsoever so I turned it back off. I did leave auto calibration on, though

[oln]

I don't think you can really bypass it as such (unless you somehow built a whole separate audio circuit). There is several things going on there, like amplification and de-emphasis, not just filtering. Someone that knows electronics well could probably figure out how to adjust the filter components to have less treble roll-off though.

[themaster1]

Maybe JVC engineers got a bit too obsessed with avoiding tape hiss and put excessive low pass filtering on the linear audio? Their later VCRs tends to overdo noise reduction on video, so maybe they did the same for audio. Even my cheap late model Samsung and LG decks don't have this kind of muffled linear audio. (though the LG ones have annoying high-pitched whine instead.) The main processing ICs used in the later vcrs typically combined head amp, video decoding, linear audio and some switching (some jvcs also hi-fi audio). It seems the audio filter is often part or fully in discrete components next to the IC though, so maybe one could modify it to filter the highs less.

I don't have BEST on my model, if I'm not mistaken that is only for European/PAL models? I did enable edit mode, but it didn't affect the sound.

It's called Video Calibration on the US models. I don't see how it would affect audio though, especially not linear audio.

it check(and adjust) the tension of the tape amongst other things

[bbmaster123]

I don't think you can really bypass it as such (unless you somehow built a whole separate audio circuit). There is several things going on there, like amplification and de-emphasis, not just filtering. Someone that knows electronics well could probably figure out how to adjust the filter components to have less treble roll-off though.

well I'll give it a shot using a tape with the issue that I don't care about, on the 3500u. If I learn anything there I may be able to apply it to the 9500u later. I have an external amp and I can apply an eq match using the audio I capture from the combo. Not expecting any success but hoping for the best anyway, wish me luck

EDIT: well it seems to have made a big difference on the 3500u. It sounds almost as good as the combo unit. With a bit of fine tuning, maybe I can have both jvc's match the combo in linear audio

[bbmaster123]

So I did the adjustment and now it sounds great (for linear audio ofc). It now matches the volume of the combo, has no weird filtered bands, and doesn't sound muffled. It doesn't sound as filtered now as the combo, more low end and such.

there is still a roll off at 14khz but there's nothing useful up there anyway, so I think in this case mission accomplished. here's my result, attached.

Funny how both jvc's had the same issue and both were fixed with a small adjustment.
then again I can't believe the 3500u works at all considering my younger brother once stuck a whole pickle in it to hopefully get to see a movie about pickles :P
Oh and there was absolutely no grease or lubricant anywhere inside the 3500u. No wonder its squeals.

[orsetto]

Funny how both jvc's had the same issue and both were fixed with a small adjustment.

Well, don't keep us in suspense! What adjustment did you make?

My JVC SR-MV50 and SR-V101 sound pretty abysmal in linear mode: if there's a simple adjustment to improve them even slightly I'm game to try it. Surprising no one has discovered a fix before: quite a few of us suffer with this JVC issue. You'd think someone would have stumbled on a fix and posted it at the JVC-centric DigitalFAQ site by now.

[dellsam34]

I wouldn't recommend messing with the factory alignment of a prime VCR, Sure if you have extras with a lesser value go ahead and mess them up, If the VCR has all seals intact and not broken, no loose parts or screws in the transport and no wear or tear it is the tape's fault, The OP happen to have one miss aligned VCR that worked for those oddball tapes but it doesn't necessarily means a brand of VCR align their VCRs in the factory to a different specification that they cannot playback all tapes properly when they are recorded on a properly aligned different brand VCR.
Low speed modes with low grade tape can be played back differently in different VCR's but that has to do with the capability of the VCR to read the fields, like extra two head with modified azimuth for low speed, 19 micron heads, better RF processing circuits ... etc which JVC is usually a champion in those areas with their high end machines.

Miss aligning a VCR for a faulty tape can be tricky, Usually the linear audio is just a matter of miss aligning the stationary head, but the Hi-Fi audio and video tracks are miss aligned by re-adjusting the entrance and exit P guides.

[bbmaster123]

The linear head has 3 screws in a triangular arrangement. The one closest to the head controls its "up-down", the one furthest controls its tilt towards and away from the tape, and the third, closest to the back of the vcr controls its skew.

I loaded up adobe audition so I could see the spectral view, and selected my xonar line in. I put in a tape with mtv videos, put on my headphones, and hit record. Then I mostly just messed around until the spectral view looked right and I could hear the hihat. If the head is too high or low it will make a high pitch screech around 7400hz. very small adjustments make a difference, but so do larger adjustments, so I took a good hour cycling through songs I knew like sweet home Alabama such trying to perfect it as best as I could. I also tested several other tapes to make sure it still sounded good.

Of course you have to be careful but it was definitely a simple procedure. I don't think there's anything to lose by trying it as long as you don't let the screwdriver slip.

[orsetto]

Much appreciate the details, bbmaster123: thanks!

I'll give your method a try next time I have a linear tape that requires using one of my JVCs instead of the AG1980 etc. That is, assuming the SR-MV50 and SR-V101 use the same linear head mount as your 3500.

delisam34, yes, totally agree with your warning that screwing around with the video or HiFi alignment is a whole other can of worms best not opened. Fortunately JVC HiFi functions much better than their linear system, so it would normally never be necessary to mess with it. In cases when one bangs up against JVC's HifI tracking limitations, there are plenty of alternative VCRs that will track those eccentric tapes cleanly (gotta fill those gear racks with something...).

[oln]

Those two jvcs have the late (probably last?) JVC mechanism which is a little different from the one used in the HR-Sx500 models. They changed the mech very slightly for the next years models, and then changed the mech a lot for the last few years of their own models. The audio head part may be the same tho, not sure. The HR-Sx400 and older models have a pretty different mech again.

A/C head adjustment is pretty similar in most newer vcrs though.

there is still a roll off at 14khz but there's nothing useful up there anyway, so I think in this case mission accomplished. here's my result, attached.

14 khz should be above the frequency response possible on the linear audio. I don't remember the exact specs out of hand but vcrs list something like 11-13 khz as the top for SP mode.

[agisthos]

I am glad I read this and its not my imagination, because my JVC 7600 seems to record audio muffled and low in quality, at least in comparison to the cheap as chips 2002 era Panasonic VCR I also have here. The JVC murders the Panasonic on image quality, however.

[bbmaster123]

If it wasn't clear the same fix worked for both my jvc's, and now I am starting recapturing these tapes from my collection! The adjustment also did not affect the video or hifi playback.

Yea anything that requires specialized tools is something I wouldn't want to get into, but slightly turning a few screws is easy enough. IMO, worth it.
But of course everyone should take my results with salt and decide for themselves if it would be worth it to them, and if the risks outweigh the benefits, in their case.

[dellsam34]

I am glad I read this and its not my imagination, because my JVC 7600 seems to record audio muffled and low in quality, at least in comparison to the cheap as chips 2002 era Panasonic VCR I also have here. The JVC murders the Panasonic on image quality, however.

If it records muffled audio it is defective (bad electronics), dirty/worn heads, or pinch roller and transport problems, This thread is about playing back tapes recorded on other machines. A VCR, any VCR should playback its own recordings perfectly unless it has a problem, First I would clean the heads and go from there.