Thought I'd carry on here rather than continue to pollute the USB to S/PDIF thread.

As reported there, I've getting the audio breaking up when playing high bit rate audio through the Hiface 2 coax route into my dac. It's less bad playing the same audio through the USB interface on the DAC, but that's limited to 44.1k.

Power to the pi was suspected, so the PSU has been replaced with a chunkier one and I intend to power the hiface independently too when the cable turns up. I suspected the network speed so moved from wireless to wired, and that seemed to help, and the problems appeared to get worse when the home lan was heavily loaded with streaming video at the same time as I was playing audio.

Today though, by way of experiment, I decided to take the pi out of the equation and replace it with my lad's W7 laptop running foobar2000. I didn't bother with wired, relying on the wifi, but did use the hiface etc into the DAC. And it worked nicely with 24bit/96KHz (one track is still suspect and i thought I could detect an occasional glitch but on the pi it's completely broken up) despite me streaming 2 HD videos over the lan at the same time.

That suggests to me that the NAS and network are OK as are the downstream audio components, which only leaves the pi.

Wondering if it was a processor speed issue, I tried overclocking the pi. That made things worse.

Other than waiting to try injecting 5V into the hiface USB directly, I'm not sure what my next step should be.

Haven't got a meter yet, but do have the rest of the power set up.

First thing to strike me is that the 5V injector cable apppears to be connected in parallel rather than isolated, so connecting/powering up the hiface caused the leds on the pi to start flickering; not enough power to boot, but some.

Connecting all up; 5V into the pi plus 5V into the hiface, the sound was fine and no problems.

Then disconnected the additional power to the hiface – no change

Then started loading up the network and streaming video from the NAS and the music starts breaking up. Stop all that and the music starts working again.

So, it would appear that adding additional power to the hiface makes no difference, but it could well be the network capacity or (quite possibly) speed of the NAS that's the problem.

Slowly making progress. I think.

I know I'm getting on a bit, but I don't think staying up to 2 in the afternoon is that late!

Yes, getting the music closer to the pi is the next step. I've already got music loaded on to both a portable hdd and memory stick, just need to mount those up and try them next time I'm home

That'd be the PC typically being up and running 24x7 with the forum open in a tab on the browser. Having just had my revised monthly electricity payments through, you might see me apparently online a lot less often

Have fun with the cables

Well that's good news! Worth the odd pint to celebrate. So what's your game plan going forward?

Indeed. I may indulge tonight

Game plan right at the moment is to put the pi back into its pibow case, tidy up the cables and use it as is with the NAS. The problems are only occurring with music at 2700Mb/s and above and at present I've only got 2-3 tracks at that speed to test the system. For the remainder of my music library, there's no problem.

Used a single-drive Synology NAS I borrowed from a friend. Just a thought… Might solve those bandwidth issues.

At some point I'm going to get another switch and co-locate the NAS with the pi, though I'm not sure that will help – my QNAP NAS might be well thought of, but it's got the 800MHz Marvel processor and the Samsung drives in it are definitely on the slow side. Co-location might be sufficient if there's nothing else going on but as soon as someone else in the house starts streaming etc, the problems might come back.

I've got a second 2TB drive that I use to backup the NAS, so I might try creating a pi-based NAS using that such that the music gets streamed from that to the pi and the main NAS is used for everything else. From what I've seen though, people are reporting 20Mb/s from an attached HDD to the pi but only 4-5Mb/s over the network when that same pi is sharing that HDD as a NAS. And that's not a lot of headroom if some of my tracks are 3-3.5Mb/s.

I guess where I'm going with this is that the right solution is to buy an up to date high powered NAS with fast disks and co-locate it with the pi, but they're not that cheap so that's not going to happen!

Know what you mean about the electric bill. I cut mine by nearly 30% by switching the fridge off at midnight and back on at 5am every day. Did it via ZWave.

As I've got an A+ rated fridge, "Economy 7" electricity (which makes electricity very cheap for 7 hours at night) and 4Kw of solar panels on the roof (which should make electricity very cheap during the day – when it's sunny) I really shouldn't have a problem.

Perhaps when I've completed my pi-NAS, solar power logging pi and my VPN network access pi then a pi project to monitor the electrical circuits to discover where the power is going is next