Rasberry Pi - nothing ... nothing .. nothing .. Gor Blimey

After reading Marco's thread about his experiences using a Rasberry Pi, with dedicated DAC as a digital source, I thought I'd give it a go myself. I've had one of the original Rasberry Pi's so didn't feel too intimidated by the idea.

So I ordered a Rasberry Pi 2 and I-Sabre DAC from Audiophonics in France. However, the lead time is long, and I got impatient. So I also ordered a Rasberry Pi B+ from RS with a battery power supply. It arrived the next day. I also ordered a Pi-DAC+ from IQAudIO (they didn't have any new stock, but had some "remanufactured" units), and one of their cases, and these arrived after a couple of days.

Since then I've had a bit of fun and games with SD cards. Initially I stupidly bought a couple of standard SD cards, rather than microSD cards. I then bought a microSD card with one of those SD card sleeve/adapters. However, when I used it the microSD card got stuck in the adapter, and in trying to get it out, I broke the card.

So today, I bought a couple of microSD cards and a dedicated card reader (with a microSD slot), only for the microSD card to slip past the socket and disappear into the casing. However, I pulled the case apart, and then it was easy to access the slot and it worked a treat.

https://lh6.googleusercontent.com/-S...ard_Reader.jpg

The card reader has two advantage - one a decent socket, and two activity LEDs so you can see something is happening (useful when uploading image files as they take a long time to write).

Ripping the image was easy via the instruction on the Rasberry Pi site (Though note - you don't want the NOOB image - just use the WRITING AN IMAGE TO THE SD CARD section to find out how to add an image to a card).

I started by trying to use runeaudio. It took me a while to get anything to work. The unit seem to lose it's IP address, and I faffed with different images and the furthest I got was to have it detecting my NAS box and index the FLAC files there. But I couldn't get any sound out.

I then tried volumio. With the volumio image on the microSD card, things started coming together very quickly. The main settings required were to set 12SDriver to IQAudIO DAC Plus and restart, and then configure the SAMBA settings to match my NAS box. That needed me to find the IP of my NAS box (via the DHCP settings in my Router), and work out the path to the folders where I keep my music. It took a couple of restarts, but finally I pressed play on the web interface (pointing at http://volumio.local/), and music came out.

The output is a little lower than my other sources, so I have to put the volume up a little (1/8th of a turn of the volume control) higher than normal.

The music is wonderful. I've put Art of Sound's :- The Ambient Collection on, and the sound is really impressive. It is a really natural sound with a lot of detail. First impression is that this is better than my Marantz NA7001/Peachtree DAC-IT combination.

I've just put Agnes Obel's Aventine on and this isn't so impressing. There is a lot of sibilance, especially on the piano work. However, the voices still sound good. Particularly impressive is the separation between the main singer and the backing singers. It is very obvious that there are two or more voices, and how they are interacting.

So it looks like I'm not binning the Marantz/Peachtree set up yet. But this is still a very impressive bit of kit. At the moment, I'm powering the unit via a basic USB wall plug (with the runeaudio set up, switching on and off didn't seem to be a good idea - so I've left using the battery unit until I've got a stable setup). I'll try the battery unit later and see how that affects the sound.

https://lh4.googleusercontent.com/-V..._pi_b_plus.jpg

https://lh4.googleusercontent.com/-Y...pi_and_dac.jpg

https://lh4.googleusercontent.com/-i...audio_case.jpg

I'm really interested to see how this set up compares to the Pi 2 with

I've changed over to the battery power supply. I'm using a RS 10400mAh Lithium-Ion Portable Charger Power Bank PB-10400. That's tamed the worst of the sibilance on the Agnes Obel album, but some is still there.

The more I listen, the more I hear small digital artefacts. It reminds me of an Arcam Black Box 5 I used to have. That DAC really pushed the lead singer to the front of the sound stage. It projected the lead into the room. However, it also had odd edges to the sound. I couldn't listen to it for long periods, and got rid of it in the end.

The artefacts are almost like small crackles. I wonder if the error correction isn't brilliant. My Agnes Obel album is one I've ripped from my CD. Downloaded albums seem to have less obvious problems.

I wonder if it's the 'remanufactured' DAC. ....

However, I can't get away from how much more music this set up is finding. If this was some new expensive Hi-Fi, I'd give it some time to bed in, so I think I should do the same for this. See if things settle down a little after a few days use.

I definitely think it is worth preserving. I've got a watch set up on the new IQAudIO DAC boards, so I might order a new one when they come into stock. And I still have the Sabre DAC to try when it arrives.

Isn't tinkering with a new gadget fun!

This is turning out to be quite a roller coaster ride. I'm playing Angus & Julia Stone's - A Book Like This and it is fabulous. Every nuance of Julia's voice is there, and you can clearly here the overlay of additional voices. It's fabulous. Oh and that is a CD rip rather than a download.

Must try some classical in a mo.

Sounds like you're going through the mill Rob . I've been using FBA for the past few years and am really enjoying it . I'm a bit skint at the moment due to a very large central heating repair bill , so haven't considered this route yet . I'll be interested to read how you get on with this .

Well Brian, it's a fascinating mill!

I've moved over to classical now, and the sound is just gorgeous. I started with some Rodderick Williams (BUTTERWORTH, G.: Songs from A Shropshire Lad / Folk Songs from Sussex). I saw him live three times last year. First at Coventry Arts Centre, then at Huntingdon Hall in Worcester, and lastly at the Three Choirs festival in Worcester Cathedral. I just love listening to him. His voice is fabulous, and he has such wonderful charisma. However, I have always been a little disappointed in recording of him. Well that's changed now! Through the raspberry pi and dac he sounds fantastic. It takes me straight back to Huntingdon Hall where he sang much of the same music (again with just a piano accompaniment).

I've now put on Vaughan Williams' Lark Ascending and I'm back in Worcester Cathedral where I heard a wonderful rendition.

So far all the classical music I chucked at the pi/dac has been handle with aplomb.

I'm starting to wonder if the pi/dac is just very revealing of poor quality rips.

One thing I haven't mentions is the Volumio interface. It is very good, and works as well via the browser on my laptop, or the android app. It makes browsing my music collection a joy.

Hi Rob,

Glad that the Pi/DAC is now hitting the spot. Let it burn in, over the course of a few days, and you'll hear the sound notably opening up and 'fleshing out'. As you're now intimating, this combination is rather special, and IMO, very musically revealing and fundamentally accurate/realistic!

Enjoy :cool:

Marco.

Sounds like you're getting there Rob . I'm sure it'll be well worth the effort as Marco says . :)

Thank you Marco, for your comment and getting me on to this combination in the first place.

Quote:

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Originally Posted by Marco

this combination is rather special, and IMO, very musically revealing and fundamentally accurate/realistic!

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The more I listen, the more I agree.

I've tweeted about my experience so far and Gordon from IQAudIO has responded with guidance as to improving the volume output. He's pointed me at the IQAudIO docs (pdf). They're really good (though I of course follow my Grandpa's advice: "if all else fails, read the manual"), but it says a lot for the kit that I was able to get everything working without them.

The relevant part is section 7 (page 19 and 20). It describes how to alter some of the underlying volume settings. You need to SSH into the Raspberry Pi (trivially easy from my Linux laptop - but Windows users will need some SSH software - something like PUTTY). You need to log in as root with the password volumio. Then use the command alsamixer to access the mixer controls. I increased the playback and playback boost levels to 100% and that got the volume up to more like the other inputs on my pre-amp.

https://lh3.googleusercontent.com/-U.../AlsaMixer.png

One setting caught my eye. DSP Prog. That's a filter setting. In other words, you can change the digital filter via AlsaMixer. It subtly changes the sound produced by the DAC. It's much like the tweaks you can do with the Audiolab MDAC.