JVC M10s Audio distortion on recording

[andybray]

I have a JVC M10s which has already been back once to have the "Loading" problem fixed (note it's a UK PAL model and so I can confirm it is not just an NTSC model issue as has been suggested elsewhere).

All was well for months. Now I get a different problem. About 50% of the time I now get a distorted audio track recorded. Sometimes it's just a few pops and crackles like on old LP but usually it's a loud crackling that masks out the soundtrack rendering the recording useless. I also find (not sure if they are linked) that a timed recording gets recorded in two parts as if the recording fails and then restarts.

I usually only find this problem after it's happened but sometimes I can get the distortion if I switch to AV to monitor what's coming out the recorder. That would remove any question of it being media related as the problem exists before anything gets actually recorded.

Anyone else seen this? Thought I'd check before the unit goes back for a 2nd time. I can't remember the last time any piece of consumer electronics of mine went back for repair under warranty and certainly nothing has ever gone back twice.

Andy

[gshelley61]

What is your method of recording? Analog input? DV stream through the firewire?

[andybray]

The recordings have been off air (analog TV tuner), usually waking from timer record.

I do some VCR to DVD using the analog front panel inputs and some DV in from a camcorder but have not noticed the problem with them but that might just be statistical but worth me trying to see if those inputs show the problem.

I also have a digital set top box which means I could try doing digital channel recordings through A/V L-2 input thereby eliminating the onboard analog TV tuner. Maybe the analog TV tuner's got a fault?

/Andy

[gshelley61]

Sure... it could be the on-board analog tuner is not getting quite strong enough of a signal and causing some glitches or dropped spots during the recording. DVD recorders don't do well with spotty signals and will hiccup as a result. Recording the digital channels from your set top box will probably eliminate the problem.

[lordsmurf]

Could be. I use cable (analog) and an antenna in my tuner quite often, swap as needed. Never any troubles. CNN is very weak, so I have issues on that channel, green stuff on screen sometimes (but only ONCE in a year have I tried to record CNN). Digital equipment, not any digital equipment, does not like crap signals of any kinds (hence all the "dropped frames" errors on cards, and TBC requirements). Nature of the technology. Digital look better, but it has a higher signal requirement. It's more needy. Sort of like a high maintenance girlfriend.

[andybray]

It's not so much that the audio is a little spotty - it's completely obliterated. So I don't believe it's a reception thing. Generally analogue TV reception is fine - digital can be a bit picky on some channels (Digital Broadcast TV - Freeview in the UK).

I'll experiment with different sources and see what happens but I'm beginning to suspect that the TV tuner has gone astray.

/Andy

[andybray]

Thanks for the suggestions. I ended up checking cabling between the M10 and the other A/V components (primarily the AV amp) as there seemed to be some noise present if cables were moved. Audio recording seems OK for now. Can't quite work out why the noise only showed up when monitoring or recording on the M10 or why it was not only heard when using an A/V source switched through the AV amp but it looks like the problem is not within the M10.

Andy

[andybray]

Well, it was not so simple.

The noise returned about a week later. I can cure it by unplugging and leaving it and then starting over which sounds like it's some sort of cumulative overheating or something. It has nothing to do with the source and so is not the signal strength, onboard analog TV tuner etc.

I can get the noise when monitoring the TV through the unit but it is worst when the unit starts to record. In some cases the noise reduces (but not quite entirely) after a minute or so of a recording.

Of course I should not get any noise at all or have to unplug the unit. If anyone else has experienced this (especially in a "loading" repaired M10 then I'd be interested to know.

/Andy

[andybray]

Well, the audio distortion did not go away - it could temporarily be stopped by unplugging and restarting. So it was reported to the reseller as a fault (12 months warranty is up in June) who this time arranged for an engineer to visit. Well I say engineer - he turned out just to listen to my explanation of the problem and then took it away. Said I'll get it back in a week or so (one hopes fixed!) and so I'll see then.

/Andy

[trhouse]

If you suspect it is a heat related problem, one test is to wait until the problem occurs and then spray the unit through its vent holes with a freeze spray that can be bought at stores like Radio Shack.

With the covers off, you can sometimes by spraying individual parts narrow it down to the exact part causing the problem.

[andybray]

Well just to close off on this sorry tale. I sent the unit for repair. When it came back the audio was fine - then guess what. The "Loading" problem came back about 36 hrs after getting it back.

Back to the repair shop. Fortunately all still under warranty but now for it's 3rd time of failure. After about 3 and a bit weeks the repairers found they couldn't get parts for the M10 and so pronounced in beyond repair and so I was given the option of a new unit.

By now the M10 was not being sold by the dealer and so I got the option of any replacement unit to the value of the original purchase price (or to pay the difference if more). Obvious choice would have been the M100 but opted for a MH20 which by now costs only £20 more than I paid for the M10 a year ago.

Of course I didn't have to buy another JVC unit and so this may prove to be a really bad decision but the dealer claims they've had few MH20s back.

Only time will tell.
Andy

[lordsmurf]

Yes, the M100 would be a great deal.
Or upgrading to an M20 or M30 would be fine too.