Distortion and after a few seconds no sound at all

I have had my MCX8000 for a couple of weeks and I have an issue which I cannot solve so I turn to you and reach for advice. I am using the MCX8000 together with VDJ 8.2. (several different builds tested) My issue is after about one minute playing a track, distortion / drop-outs starts to be heard and seconds later all sound is gone. MIDI is still working, VU meters act normal. MCX8000 is responsive. All seems ‘ok’ except for no sound out. I have done a deep analysis, trying to find the issue without doing so. MCX8000 has the latest firmware downloaded from Denon’s website.

Here’s what I have tried: Using Denon ASIO driver 1.0.5, buffer size does not matter Using ASIO4ALL. Exactly the same issue persists. Even with WASAPI with shared mode active, this issue will happen. Running WASAPI with excelusive mode seems to not have this issue, but latency will increase. 2 different PC’s tested with exactly same results. The issue is so easy to reproduce. If I change USB port or reinitialyze the ASIO driver, sound will resume again. MOST often, it will work for hours after doing this, but I have had the issue occouring again. The issue is not connected to a particular USB port, but changing it will normally help the issue. I don’t know what to check and start to believe there might be an hardware issue with my MCX.

Can you elaborate on this point? The beginning of the sentence seems to conflict the latter part.

It does not matter WHICH port I am using. The issue will occour on all. But just putting the USB cable in another (which ever) seems to help

What are the full specs of the lappy?

When you mention that everything starts off ok but then later distortion creeps in… what sort of period, from cold (eg: laptop off for an hour) does normal playback work, before the distortion starts coming in?

How many USB ports does your lappy have? How many are in use simultaneously? What’s on the other USB ports? Any USB hubs?

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I’m using small desktop PC’s with ITX boards. CPU: i5-4690k, 8GB ram. Use only USB for mouse/keyboard + MCX8000. Does not matter connecting MCX to USB2 or USB3. No hub. When starting up, the track will work for one minute (independent of hot n’ cold) During this minute all is good.

I’d be trying an entirely different pc … nothing wrong with mini/micro PCs, just as a test/compare. Some smaller psu’s are known not to deliver full current to all USB ports continuously however. I recall an instance where someone’s USB sound card would establish a connection but wouldn’t -hold- a connection for long IF the lappy was used with its “in he box” lightweight low current psu (the overall weight of the lappy looked better on paper if the psu weighed less) - the lappys USB ports only delivered good continuous working performance if a heavy duty (and heavy to carry) Psu was used instead.

I’d be checking the motherboard USB 2 and 3 drivers especially if it’s a shared/combo driver, the motherboard bios especially anything related to USB power and overall USB traffic - all USBs are good at transferring large amounts of data … in bursts… but not all usbs are good at transferring data continuously.

Other than that… try different USB cables (shorter the better and never over 5 metres), and optimising the PC with dpc latency checkers. If all looks good there then you could try taking your pc to a local friendly dealer and trying your pc in their MC controller to see if the occurrences follow the controller or the pc. If the occurrence follows the controller, then utilise the warranty.

I have verified the issue on two different PC’s already. Exactly the same. I will try another application, maybe use the included Serato app included in the MCX8000. I am not worried the PSU’s are too small, they are actually 300W SFX PSU’s. If the USB’s were at fault - just initialize the Denon ASIO driver cure the issue, it’s not really logic. Investigation goes on!

Try to disable selective shutdown of USB ports on Windows. In power settings…

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Thanx for all advice.

I think I have been able to nail the issue, and after changing the BIOS setting “Intel USB3.0 controller” to disabled. That fix it. This makes the USB3.0 ports revert back to USB2.0 ports, but that’s no issue for me as long as I get a stable system.

That is after updating the bios to latest and not able to fix in another way.

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It is surprising just how long the computer industry takes to fully accept (and be compatible with) new “industry wide” changes, such as USB3 implimentation.

I can recall about five years ago there were external hard drives coming out with 2 different back pieces on them - a sort of “have this usb2 back piece for the moment, then buy our usb3 back piece later if you need usb3”

And even now usb3 drivers, even at bios level, seem a little buggy.

I thought USB had some agreed standard.

Is USB 3 as standard on controllers overkill? especially one like the 8000 with so many features.

I’m guessing Denon wants it to be compatible with so many laptops from a business/sales perspective.

Legacy hardware Rane SL1 which is USB 1 works well with USB 3

I would think rather there is some issue with the USB3 controller itself making it not properly suitable for audio throughput over USB3.0 mode. It can handle very high speed, but even if audio and midi does not need the maximum speed, our DJ application relies on constant and reliable USB communcation. Maybe the USB3.0 controller in my PC is more suitable for data transfer of thumbdrives and harddrives not requiring constant performance.

I’m just very glad the BIOS offered a way to shut down the USB3.0 mode and use 2.0 instead. And my MCX8000 work brilliant in this mode!

This is a key aspect, often overlooked. Data device manufacturers are great at quoting the BURST speed of a device, but not the amazingly slow (in comparison) constant transfer rate. Its like asking an Olympic sprinter to keep his/her sprint speeds up for a whole mile … it’ll never happen despite his/her best efforts.