Having put the files on a USB drive they played perfectly so I'm blaming the network/NAS for the audio glitches on high bitrate audio (probably the NAS as it has a slow processor and slow drives). I presume that Gnome on the PC does some buffering to accommodate irregularities in streaming from the NAS and the Raspyfi doesn't and hence is more affected by them.

Not sure how I solve that without spending lots of money.

Whatever, with the exception of the few tracks that I downloaded to try the high definition audio, all my music is < 1500kb/s so I'm just going to leave well alone and enjoy the music.

Only tried it with the 5.25V 2A Modmypi PSU so far

powered up pi (bare) = 5.42V
plus sd card = 5.20V
plus hiface 2 = 5.06V
plus ethernet = 5.03V
playing music whilst reloading database = 5.01V

Still worth going the linear PS route even though you've ruled it out as a possible cause of your issues.

I'll add it to the to-do list, Though i think I need to do some more work with powre tools or I'll be sleeping in the shed

I played with USB cables and DACs over the last 2 nights or so and the most striking difference was the improvement in dynamics and clarity when going from a standard USB cable to one I had reduced to 6" and severed the +5V red cable coming from the Pi. I then used a LM 317-based PS I made on the power wires going to the DAC. Not sure if its the shorter length or the linear 5V (or both) but its definitely worthwhile.

As the injector cables were not too expensive, i may try snipping the +5V, but at the moment as the system is working nicely with the hiface plugged straight in to the pi I'm tempted to leave well alone - at least until I've got my meter back and measured the voltage drops with hiface on and off the pi psu.

. Wouldn't have thought USB cabling would have made an audible difference but I guess if other cables do then why not USB? Surprising how some relatively cheap wire and connectors (US$30 the lot) might make a noticeable improvement.

I think a lot of this depends on what the DAC is doing with the data. If it's buffering and reclocking there would probably be no difference, but if the DAC is relying on the input signal to clock the data through its circuits then the differences could be significant (though I'm not going to say better or worse)

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

I played with USB cables and DACs over the last 2 nights or so and the most striking difference was the improvement in dynamics and clarity when going from a standard USB cable to one I had reduced to 6" and severed the +5V red cable coming from the Pi. I then used a LM 317-based PS I made on the power wires going to the DAC. Not sure if its the shorter length or the linear 5V (or both) but its definitely worthwhile.

Going to be interesting to see if there's any improvement with the silver Litz wire and the 'gold' USB A and B connectors I am patiently waiting on. Wouldn't have thought USB cabling would have made an audible difference but I guess if other cables do then why not USB? Surprising how some relatively cheap wire and connectors (US$30 the lot) might make a noticeable improvement.

Recently I indulged myself and bought a Topping T60 amp to see how close it came to some home-brewed Tripath amps driven by a Chinese tube-based preamp (surprisingly good given it cost US$70) and wanted to break it in for a week or so given it didn't sound so great out-the-box. I did not want to run it on my home LAN with the Synology NAS - just didn't want the NAS churning away for a week! So I bought a ZyXel MWR102 wifi router for the princely sum of US$17.99 and set up a completely separate network at home with the Pi connected via cable to a cheap switch. Used a single-drive Synology NAS I borrowed from a friend. Just a thought... Might solve those bandwidth issues.

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.

So it would certainly appear that the problem I'm having with higher rate music is with the network and/or NAS, not the pi (nor the power supply, nor the HiFace 2 nor the DAC... phew)

Happy dance

I'm putting my complete music collection on my WD removable drive (once I've reformatted that as FAT32) so will have all of it available to play (hopefully) while I work out what to do next. to resolve the "getting the data to the pi" problem.

Have fun with the cables

Off to try different USB cables (including 5V linear injector cable) to see if I can hear a difference. And whether bypassing F3 alters the sound. And anything else a few G&T's suggest....

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

Good. Progress, indeed. Guess you could always 'prove' it by running a USB HDD with some 24-bit music (and it's own power, of course) or try a USB stick on the powered hub - bypassing the LAN for all but the control apps. Unmount the NAS from auto.nas!!

There, now you are allowed to go to the pub....

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.

Will need to re-check once I've got the meter back.