XMOS-based Asynchronous USB to I2S interface

[RayCtech]

Originally Posted by staki

Not sure at all, but it is possible that USB Audio Class 2, although recognized by recent Linux kernels, only works on i386 architectures, not ARM ones.

I have a CuBox (Marvell Armada 510 SoC) CuBox that performs very good - kernel and MPD are compiled for ultimate performance for WAV, AIFF and DSD. Base filesystem built with debootstrap.

Have also started the works for a iMX.6 quad core (Freescale) 2GB RAM system.
The 2GB RAM (4GB later) are "needed" for buffering / caching playlists in RAM...

These two systems have gigabit network and SATA.
Most of the other ARM systems do not have gigabit and SATA, and often have most of the IO implemented over USB and are thus not recommended for use with USB 2.0 audio adapters.
A USB connected network or USB connected HDD / SSD / Flash storage should be avoided...

EDIT: For optimal performance clock on USB adapter, USB clock on ARM board, ARM CPU and ethernet clocks are changed from the typical 300 ppm (up to 500 ppm) to custom 20 ppm / less than 1 ps jitter clocks.
Kernel are custom configured and USB / ALSA drivers are custom configured / patched and also MPD are custom configured and patched to allow for my configuring options.

[clivem]

Originally Posted by Ben Mah

My tda1541a dac with I2S input supports 96 kHz max, so I have not tried higher sampling rate. However, definitely 96 kHz material passes through to the dac with no glitches.

Any chance you could ssh to the device,

cat /proc/asound/card1/stream0

and post the output, while playing 96kHz? (You might have to change card1 to whatever index the WaveIO has been recognised at.)

[clivem]

Originally Posted by staki

Not sure at all, but it is possible that USB Audio Class 2, although recognized by recent Linux kernels, only works on i386 architectures, not ARM ones.

No reason why that should be the case. It shouldn't matter what the architecture is as long as the code for the usb driver is good. We know that the alsa driver works just fine with the card, as long as it is recent enough.

[clivem]

Originally Posted by deandob

If you want a more powerful ARM based board, good price & build, decent community support check out https://www.olimex.com/Products/OLinuXino/

The A13-OLinuXino-WIFI is an interesting board at a nice price, using a GL850G for USB hub, which from my experiences with external powered hubs which use the same chip, is not going to be a problem with Linux. I don't suppose anyone has tried the WaveIO with this board?

[clivem]

Originally Posted by RayCtech

I have a CuBox (Marvell Armada 510 SoC) CuBox that performs very good - kernel and MPD are compiled for ultimate performance for WAV, AIFF and DSD. Base filesystem built with debootstrap.

Thanks, Ray. I'll order one. I'm not looking to run mpd, rather squeezelite, which is a software player that is controlled from Logitech Media Server (SqueezeBoxServer).

[clivem]

Originally Posted by Ben Mah

My tda1541a dac with I2S input supports 96 kHz max, so I have not tried higher sampling rate.

Ben, just out of interest, which version of the Pogoplug device do you have? Is it Series 4 or V2 with an ARMv5 chip or Pro/Video/V3 with ARMv6?

[qusp]

Originally Posted by Lorien

Well, not too much besides adding one-two more in parallel with values not too far from each other to avoid antiresonance effect. I would go on other decoupling scheme involving Murata and TDK products. I guess there are more than two years ago when I found some EMI filters that got my attention but are harder to solder for a regular DIYer and comes in 0603 package (imperial) with 4 electrodes. There's not such a footprint on actual WaveIO card. I still suggest to place your 3.3Vreg close to the isolator power pins. It will make your life much easier
Merry Christmas,
L

I guess you mean the Murata EMIFIL NFM/L/R/E range? excellent parts, they look like 4 terminal but are 3 terminal. they come in larger than 0603 these days, right up to 2220

[Ben Mah]

Originally Posted by clivem

Any chance you could ssh to the device,

cat /proc/asound/card1/stream0

and post the output, while playing 96kHz? (You might have to change card1 to whatever index the WaveIO has been recognised at.)

Luckit Luckit USB Audio 2.0 at usb-orion-ehci.0-1.1, high speed : USB Audio

Playback:
Status: Running
Interface = 1
Altset = 1
URBs = 8 [ 8 8 8 8 8 8 8 8 ]
Packet Size = 1024
Momentary freq = 96003 Hz (0xc.0018)
Feedback Format = 16.16
Interface 1
Altset 1
Format: S32_LE
Channels: 2
Endpoint: 1 OUT (ASYNC)
Rates: 44100, 48000, 88200, 96000, 176400, 192000
Data packet interval: 125 us

[Ben Mah]

K

Originally Posted by clivem

Ben, just out of interest, which version of the Pogoplug device do you have? Is it Series 4 or V2 with an ARMv5 chip or Pro/Video/V3 with ARMv6?

It's a Pogoplug V2 (E02) with an ARMv5te Marvell Kirkwood 1.2GHz processor, 256 mb ram, gigabit ethernet, and four usb ports.

[clivem]

Originally Posted by Ben Mah

It's a Pogoplug V2 (E02) with an ARMv5te Marvell Kirkwood 1.2GHz processor, 256 mb ram, gigabit ethernet, and four usb ports.

Thanks for that and posting the output above. I've already ordered a CuBox and I think I'm going to order a A13-OLinuXino-WIFI as well to have a play with.