What borks my recording every 15 minutes?

[Steve Crook]

First thing to say is that I'm sure this isn't a VS problem. There's something shifted on my laptop that's started causing it. Basically, every 15 minutes there's a 'dropout' on the recordings I make. There's a short flat part of around 0.25 seconds where there's no sound. Sometime there will be a single one of these, sometimes a pair within one second, with a small bit of the recording between them. They appear to occur, as precisely as I can work out, every 15 minutes. So usually one per side, and, rarely, two. It appears that the 15 minute cycle isn't related to the act of recording, but going on all the time on the laptop, and the position of the gap just depends on the point in the cycle at which recording starts.

Normally I record to an SSD over USB3 (Windows 10) but I see the same problems recording to the laptop's internal SSD, so I don't think it's a disk write issue. The laptop is working well within capabilities too, so I don't think it's CPU. And to emphasise, I've been using this arrangement for a year and have made more than 100 recordings without seeing the problem. The Windows eventlog offers nothing that cries out for further investigation.

I've tried using my desktop machine and can record OK.

So I'm convinced it's the laptop. But what could have changed? Both use the same AV software, both are Win10. I'm preparing to wipe the laptop and start from scratch. But it's a pain to do, and I was wondering if anyone had seen anything like this...

[Paul Sanders (AlpineSoft)]

Hi,

One thing to try is unchecking 'Use WASAPI for Recording' in VinylStudio's Check Level dialog.  That might fix this.  You can reach this dialog from the Record window.

Other than that, have you installed any new software (especially driver software) recently?  It sounds like something may be interfering.

[Steve Crook]

I'll try the WASPI suggestion.

I've not installed anything new recently, but as always with windows, it's a series of rolling updates to the OS and applications. I suspect either the OS or virus scanner I don't see anything else messing with the laptop at this low a level. I've not checked to see if the gaps are actually something that's missing or if they represent a pause in the bitstream from USB. Mainly because I'm not sure if I'd ever really know given how short they are... It wouldn't entirely surprise me if it turned out to be a *delay* rather than a cut.

If I come to any serious conclusions I'll post here. But I'm getting to the point where it's going to be more time effective to just wipe the laptop and start again...

[Paul Sanders (AlpineSoft)]

OK, noted, thanks.

[Steve Crook]

Tried WASAPI and that didn't work. Same glitches, same spacing. I did fiddle with them in cleanup and I'm fairly sure they're empty space rather than somewhere the data has been lost. If delete them the ends of the waveform look like a good fit at 2000% magnification.

I'm going to reinstall windows. I doubt I'll ever get to the bottom of it. Frustrated doesn't even begin to do my mood justice.

[Steve Crook]

I may have to get the the bottom of it or buy a new laptop :-|

I restored the Dell XPS 13 back to factory, did all the windows updates, installed Bitdefender then VS and can reproduce the problem with WASAPI. I tried installing ASIO4All, but have had some problems getting VS to accept using ASIO4All for recording *and* getting monitoring to the laptop speaker.

So I installed Audacity, and after some swearing (nothing like it for appreciating how good VS is though) I managed to do a recording using DirectSound and get the same problem in Audacity. A gap of nothing, roughly 0.03 seconds in length.

I've done everything I can to ensure the laptop isn't doing anything to the USB ports, so no attempts power save them, CPU is 100% and the power is plugged in. I'm using a good quality 750cm USB cable plugged directly into the laptop.

All recordings are being done 24bit 192khz. I'll try dropping the quality to std CD and see if that makes a difference. Then I'll switch back to using my desktop to be absolutely sure there's nothing going on with that.

Given the (in)frequency of the problem I'm beginning to wonder if it's been going on for a while, and I just never spotted the glitches. You really have to be listening to spot them first off, though once noticed, they're impossible to ignore....

Is there any way I can search for these in a recording? The track spotting algorithm won't pick up gaps as small as these, and I'm not aware of anything else I can use.

[Paul Sanders (AlpineSoft)]

Hi.

VinylStudio has no way of searching for these I'm afraid.  Could it be down to Bitdefender?

Also, you could check whether there are any updated audio drivers for your laptop.  Not sure what else to suggest, it must be really irritating.

[Steve Crook]

I don't think it's bitdefender, it's on my desktop machine and that doesn't have these issues. I have a friend visiting at the weekend and I'll hijack her laptop and temporarily install VS on it (with your approval) and see if I can reproduce there. Different laptop manufacturer, but still using bitdefender AV.

I suspect this is something to do with interactions between the OS, drivers and USB firmware. I may take the time to uninstall Bitdefender and try again, in for a penny in for a pound I suppose...

Drivers and firmware are all up-to-date.

I know nothing about how data is delivered from USB, but I'd always imagined that at application level it would be like reading a file, socket or pipe with blocking reads or using a 'select' to get told when there's something to read. But, given these gaps, I'd infer it's a bit more complex than that :-)

Irritating doesn't even begin to describe it. It's disconcerting when part of the infrastructure that 'just works' fails. Doubly so when it highlights how little control I have over something that's so important.

[Paul Sanders (AlpineSoft)]

Hi,

Yes, that's fine, go ahead.  I don't know what's going on either.

[Steve Crook]

Ok. Tried on an HP laptop with same AV software and have had no problems. So whatever it is, it would appear to be a Dell XPS thing. Which is a shame as I'd been planning to upgrade my laptop and a new XPS had been at the top of the list but the last thing I want is to get the new one and find it has the same issues. So I'm looking at alternatives.

I'll continue to tinker and Google, but this has already soaked up enough of my time so it'll only be when I have nothing better to do...

[Paul Sanders (AlpineSoft)]

OK, thanks for the update.  Are there any newer audio drivers on the Dell website?

[Steve Crook]

AFAIKT I'm up to date with drivers. Dell have a fairly good system for notification of driver updates, but I've also been and looked just in case. I've reviewed some of the earlier recordings, and I'm close to certain that this problem has appeared relatively recently. With a driver/bios/windows update...

I'm mulling over the time and pain in reporting this to Dell and getting someone to take it seriously. Starting with 'Have you tried switching it off and on again' :-)