TOPIC:

Before setup:
1. iMac without grounding
2. The miniDSP connected through an Aluratek 4xUSB hub and with keyboard, a HDD, SD and LED VU meter also connected to it.
The problem occurred several times a day.

Now setup:
1. iMac grounded.
2. miniDSP directly connected to a USB connector to my iMac
3. Added a ferrite core on the USB cable.
The problem appears to be gone.

Either sharing the USB connection or some common mode current noise seem to yield this latch-up problem. The USB VU meter I am using probably did some 5V noise, but also without it, I still had the problem. Until miniDSP finally fixes the actual root cause, try above.

petermortensen wrote:

1. iMac grounded.
2. miniDSP directly connected to a USB connector to my iMac
3. Added a ferrite core on the USB cable.

So, what do you mean by grounded?
My computer's power supply is connected with a 5-15P cable. I used the included USB cable which has a ferrite core and it's connected directly to a USB2 port on the motherboard.

Also, just to further compare notes. When this symptom occurs I observe the following:

1. Computer acts like USB audio is still functional.
2. I can still connect to 2x4HD though management apps.
3. Management apps do not show sound being output.

The next time this happens, I think I'm going to try and run sound through the TOSLINK or analog jacks. See if the problem is just limited to USB.

By "grounded" I mean the power plug ground pin is used ( = use a 3 pin power plug for my iMac).
If you are not using a USB hub, you might want to try another USB cable.

But, miniDSP should get this problem actually fixed rather than rely on people to do these random work-arounds. Their support is not pushing their engineers to get to the root cause, it seems. I even first tried to solve this problem by buying another USB hub, but that didn't help at all.

And yes, the box appear as if it is running with the USB audio still active and their software still communicating, but no audio is coming through it. I have this problem on Mac OS and you have it on Windows.

Other than this, the product is great and it's a bummer they can't get their act together to investigate possible failure modes and fix what this is about.

Reporting back... USB dropped out again. Without rebooting the 2x4HD, I simply hooked the TOSLINK up to my computer and switched inputs in the configuration app. Everything worked just fine. Switched back to USB, still dead. For my purposes... I'll just stick with TOSLINK.

Agreed that this needs to be fixed.

Just over the last 3 days I had this problem happening twice. And that is with a direct cable from a USB port on my iMac. This intermittent SOFTWARE BUG in the miniDSP 2x4 HD needs to get fixed. I'm sure several people, including me, would be willing to run a debug version to help getting logs made that can pinpoint the root cause.

Dear All

Just seeing this thread. Please remember to always start a support ticket if you have a question. That's where our team monitors issues and provides support. As per the heading, this is a community based support forum. i.e. support by community members who want to share ideas/help each others. Thanks for your patience and understanding!

We'd be happy to help on this. Whoever has an issue, would you please start a support ticket with us and we'll investigate (support.minidsp.com).

On the 2x4HD, we're using USB 2.0 high speed as we're doing bidirectional audio in mulitchannel. It has some specific timing where some hubs on the path might be an issue.. We could be wrong but don't think that it's a specific bug as have some huge community by now. If all customers had an issue, that thread will be a LOT bigger. I think that it's most likely some interference in some specific cases.. We've had an engineer this week test the board on all PC/Mac through the office, some with very long cables. We couldn't get drop out but we have an idea worth testing on some of you. We'd just need the board shipped back so we can help do a little rework.

Looking forward to fix this issue!

DevTeam

I indeed started a support ticket in mid March this year and even went to buy another hub. That didn't fix the problem. Then finally I went for a direct wire from my iMac to the miniDSP 2x4 HD. I thought it fixed the problem but really, it has just lowered the frequency of the problem.

This is NOT about hubs, Macs, PCs, wires or anything external to the box. The box itself is in a faulty mode where it doesn't recover normal operation. It's possible that some data error can cause the faulty mode of the box, but still the box has the bug. This is important to understand. I can not recover the failure mode in any other way than to power reset it. This is what others seem to report also.
In the failure mode, the USB interface still allow data communication but not audio to come through. It also seems to work with optical audio. It might occur more often when your running 192kHz sample rate from source. At least that is what seems to be the case for me.

And in terms of how many people report such problem. Truth is a lot of people will do a power reset, and if it works, they will not report it. I bet almost nobody will report this issue if a monthly power reset can keep them going.

My setup looked like it was fine for many weeks and then just now after I started using Amazon Music HD, it has come back. Amazon Music HD switches between different sample rate modes, and I don't know if that matters. When I had the problem most frequently I had a hub connected and an SSD and HDD on that same hub.

"Fixing" a problem without knowing the actual root cause is not ever a good idea as this example shows. Telling customers to swap a hub or use a direct wire is not a fix cause you guys still don't know what the root cause is.

I will gladly contribute by swapping the box with one you believe is working, if you think it's hardware related, or run some debug version, if you need log data.

I've experienced the exact same issues reported by petermortensen. I've opened a new support ticket.

Just happened again in the middle of watching a Youtube video. Now I'll fix the sample rate to 48kHz to see if that helps anything.

...later in the same day, the problem happened again also with 48kHz...

I created a support ticket, too.

I stopped using the unit because of the problem. If it would help to send the unit in to diagnose the issue, I'm more than happy to.

While I hope the support tickets help, I think this public thread seems like a great way to encourage people to report their issue and combat the notion that "we haven't heard from enough people who have this problem, therefore it's probably not a bug." Enough people are on this thread with the exact same symptoms and the only one common thread between us all is that we have a miniDSP 2x4 in the mix. Makes ya' think....

At the beginning, I also experienced this problem with my MiniDSP 2x4HD. (3 years 4 months ago )
I created a support ticket, explained the same problems as the people here, but didn't hear any steps to resolve it at the time.
Later I went through a series of firmware / driver updates and now I am using the latest firmware 1.12, driver 4.82.0 and plugin 1.15 and I have not seen this issue for a long time.

I will not claim that the problem has been fixed, or that even firmware and driver updates are the solution.
Simply, the problem has disappeared and has not recurred yet.
Just as a tip to anyone who comes across this issue, try updating your firmware / driver / plugin to the latest available Rev. 1.15 / FW 1.12 / July 2020 and see if that helps.

I've now found out when my box gets into this mode. It happens at the exact time as my home office mini refrigerator relay turns on or off the compressor! In other words, AC noise can cause the box to hang the audio stream.

And my refrigerator is UL approved and doesn't cause any other issues.

It made me first conclude it is a hardware problem.

To confirm this, I measured the DC 12V output of the power supply and can see it does some weird oscillation when my fridge turns on/off the compressor (a huge 5V peak-to-peak variation). So I thought it was this causing the problem.

Then I swapped it to another 12V DC power supply. And guess what?
The problem did not go away. I can still force the miniDSP box to stop playing by simply unconnecting/connecting my fridge from the power plug.
And I tried a third power supply (all are different except they are 12V DC). Same thing. I can super easily reproduce the problem with whatever power supply.

I see three patterns happening when my fridge compressor turns on/off

1. The sound disappears for a second but comes back.
2. The sound disappears and the box goes into the failure mode of no audio (requires a reset of the box to recover).
3. I hear no problem.

Out of 5 connects/disconnects of my fridge, I get typically one case of #2 above.

I can't judge how the AC noise from the refrigerator crashes the miniDSP box. I tried adding a capacitor and also extra ground wires across the connectors inside the box, but that didn't' solve it.

Thus I ended up leaning towards the software being vulnerable to data errors caused by noise. If so, simple ESD testing during operation can probably cause the same problem or just emulating data errors by some random shorting of the data wires. I feel tempted to open a USB cable and try to see if I can provoke the problem by injecting intermittent noise in the data.

My box is connected directly to an iMac.

I've added some ferrite beads on the wires connected to the miniDSP box. It looks like these can help eliminate the problem in my setup.





It's a bummer that miniDSP has not spent the effort needed to get this crash problem fixed for so long. In my setup, it's super easy to reproduce by just disconnecting/connecting my mini-fridge with the compressor starting. I can reproduce it in seconds every time without the ferrite filters.

Just some follow-up, I sent my unit in and when it came back... it was still experiencing the same issues. Reading over your replies petermortensen, I think I'm going to try plugging into a nicer linear power supply and make sure it's sitting on the battery-backed side of my UPS. Maybe that will fix the issue.

Yes, you might be able to avoid the problem by using a UPS. Whatever is the root cause is for miniDSP to fix and it's sad they don't seriously care to fix it.

I believe this problem is likely to be reproduced in one of these ways while in use:

1. Inject ESD through an ESD gun on the metal chassis of the box.
2. Split the USB cable with the data pins open and add some random noise to the data (e.g. short the wires randomly).
3. Add some mains AC noise using some heavy inductive load e.g. a powerful AC motor (my mini office refrigerator compressor works).

I've wasted too much time on this issue buying two different USB hubs, adding extra grounding to my setup, shifting around cables, adding capacitor inside the box, trying different power supplies, and now added these ferrite beads. I've even added a power switch that is Alexa controlled so I can reboot my box with a voice command. I don't believe replacing my box is a fix when the root cause is not understood by miniDSP.

This box is not recommended until they fix this problem.