TOPIC:

Good day,

First of all, huge thanks to the miniDSP team for working on this product! As a headphone enthusiast who likes tinkering with various crossfeed algorithms and other DSP applications, I really appreciate the fact that now I have a great playground.

I have tried using the HA-DSP I received, and immediately run into some troubles while connecting it via USB.

First, I tried connecting it to Plugable powered USB Hub (www.amazon.com/gp/product/B008ZGKWQI) connected to my Linux workstation (HP Z600). I've got the HA-DSP device listed among audio devices, but my attempts to play sound via it failed. At the end my workstation just hanged, and I had to reboot it.

Then, I tried connecting the HA-DSP to Nexus 5X phone running Android 7.1.2 via the manufacturer-provided USB-C to -A adaptor. Initially there were no sound as well, but as I had flipped the back switch (labelled "1 2 3" back and forth) the device has got recognized, I I've managed to play several seconds of audio. After that, the phone rebooted.

The HA-DSP seems to work fine from the analog input.

Are there any known issues with the USB Audio implementation in HA-DSP? Could I expect any improvements? I can help you with debugging, at least on Android devices, as I actually work on the audio framework in Android.

UPDATE:

With MacBook Air (2011) running OS X 10.11.6 HA-DSP seems to be operating more stable. I suppose that Mac and Windows are the primary platforms considered to be used with the device. But I guess having it working reliably with mobile devices is also important especially considering that it's a portable device.

@ Naganov

Thanks for your feedback. Let's try to see how we can help
1) USB c to A. Did you make sure that you used an OTG adaptor? We're shipping one now with our products. It looks like this.
Note that these adaptors (at such low price) are a bit flaky... We had to use 2 before settling on one that works and supplying it with everAMP.
www.gearbest.com/chargers-cables/pp_3928...bK1lGvLlMaArlq8P8HAQ

My guess is that the issue with the nexus is related to OTG issue.

2) More than happy to hear your feedback with all this being said.. Please feel free to reach out via support.minidsp.com for our tech support portal.

3) For the Linux setup, I'm afraid that we don't provide support for Linux, but it should be plug&play with ALSA 2.0. 2x4HD, USBStreamer and such been working fine on a similar implementation. We can have a quick test later on to see..

HTH

Thanks for your reply!

With Nexus 5X, I was using the USB-C to A OTG adaptor provided with the phone. In my HA-DSP packaging there are only A to micro-B and micro-B to micro-B USB cables. I've ordered the adaptor you mentioned, will try with it.

Another issue with Android is that it always initializes USB Audio devices at maximum sample rate and bit depth they support. Since HA-DSP supports high sample rates, I may have created a big strain on the system because it had to supply very high bitrate audio stream. I will check what is happening there a bit later.


Another issue with USB I have noticed so far, is that the device reports that it supports input channels as well as outputs -- see the screenshot. It may also create problems on Android actually, because the audio system will be trying to use it as a microphone.



Thanks again for your support!

@ Naganov,

Thanks for the feedback.
The HA-DSP is indeed 2x2 now. We're using this as a way to debug, we need to remove it.. Next rev of firmware, we can easily do so.

DevTeam

@DevTeam,

I've got some kernel logs from a Nexus 5X device which constantly reboots as soon as I connect HA-DSP to it. I tried both the USB-C-to-A adaptor you have provided a link to, and another adaptor.

It might be interesting for you to take a look. Looks like the device doesn't respond to the USB driver requests, and this completely messes it up, causing a crash.

Log: pastebin.com/Y6UijhJ8

@ Naganov,

Thanks for the log. Something is indeed very odd.. We have few Android devices here, none are having the issues you have.
I wonder if you have installed maybe some app/drivers on your device that create that trouble. When looking at the logs, it's calling up the "snd-usb-caiaq" custom driver for Native Instruments instead of standard snd-usb-audio that every usb audio device would typically call.

That Native instrument driver is the one creating the issue I believe. Do you maybe have a Native Instrument app on your phone? i.e. phone getting confused..

Just a thought.

DevTeam

Thanks for chiming in!

It's not really possible to install custom drivers on Android. The module you are talking about is part of the standard ALSA package, and is part of the Linux kernel:

elixir.free-electrons.com/linux/v4.4/sou...SA-Configuration.txt

It's only mentioned in the log once, during its registration, so I don't think it's causing any problems here.

I believe that in my case, HA-DSP can't be connected even as a USB device, the initialization really hasn't even arrived to the USB Audio drivers level.

I will try HA-DSP with more Android Nexus devices to see if there is any pattern here.


BTW. What's the purpose of the USB-A port on HA-DSP? Can it be used for hooking it up as an USB Audio device, or is it for debugging purposes only?

Hi

Thanks for the great feedback

1) We've officially ran out of Android devices we can test here inside the office after stealing them from each staff member. All of them worked fine as per our initial test. We also performed test on a bunch of USBC to microUSB adaptor sourced locally. We did find one that wasn't advertising the HA-DSP. Most likely low quality at 2USD a pop.. Replaced it and it worked fine.

2) I think it would be of great value if you could maybe try to find some Android devices to test it against something else than the Nexus5 + Android 7.1.2. Our android versions were lower here. e.g. Huawei has 7.0. Knowing if it's hardware (e.g. could be adaptor, cable) vs Android rev vs XMOS firmware would really be useful. A nexus 5 is 2k HKD over here, if we start sourcing every version of Android, it is going to be a bit of a pricey exercise.. If indeed it's Nexus specific, worth for us to get one to investigate.. So far no other reports from other customers, so more data would certainly help. Thanks.

3) Here is one of the test setup (Huawei P9 android 7.0 - > USBC adaptor -> OTG cable (provided inside box) -> HA-DSP). Plug&play discovery.



4) The USB A can actually be used for streaming too.. Just connect a USB a to USB a cable from say a PC.

DevTeam