Which is better: A DIY DAC via I2S or the Meridian Explorer USB external soundstick?
Hi AudiophilePi,
on the Raspberry Pi, the Ethernet is driven from the same device as the USB connected to the host ARM processor. Using USB for audio also increases the CPU load over I2S - this leaves less CPU for audio decoding / network traffic handling / memory card reading and your selected application to run increasing the potential for buffer under runs and gaps in your data stream.
For me I’d select local i2s over USB (as a transport) for audio.
Then consider the DAC in use. Even if the actual DAC chip being used was the same in each case there may be implementation issues (different Left and Right track lengths, interference, power supply noise etc.) on either device making one slightly better than the other. One DAC chip used may also have additional features (EQ / DSP) etc over the other which may sway your decision. There is also the consideration of aesthetics - do you want another external box? Then with the Pi having only 2 USB can you spare one for the DAC, or do you need WiFi and Bluetooth?
All this will be different on non Raspberry Pi - I just use that as an example.
I notice the Meridian uses the TI PCM5102 (doesn’t say it it’s the A or the previous version). It’s a good DAC and used on some Raspberry Pi DACs, and we too considered it’s use but it’s THD/THD+N isn’t as good as it’s big brother, the PCM5122, which we use on the Pi-DAC
Finally, there is the price comparison, an IQaudIO Pi-DAC will cost you around 1/10th the price of a Meridian Explorer. 
HTH,
Thanks gswg! I ordered the IQaudIO. Does it come with instructions?
Does the DAC work asynchronous?
Greetings,
Hi, instructions are here…
iqaudio.com/wp-content/uploads/2 … IO_Doc.pdf
PM me wrt the asynchronous question.
The IQaudIO does not sound good. It has glitches in the very high frequencies that hurt my ears. But then again, my CD player sounds awful too! I changed every single piece of my HiFi set, and still I get these glitches. My set is on the same group as my freezer and dishwasher. Maybe that may affect the soundquality negatively? It is the only group with ground near (live cheap sound great 
). How may inadequate soldering connections affect the sound quality? Maybe the line output oversteers for my amp input? (my volume control is stuck at 100)
UPDATE: A silence track does not generate any audible distortion. The distortion is the result of playing content.
UPDATE: Maybe the stuck volume knob that is fixed on 100 makes my amp clipping…?? Now trying software volume control (does not sound as good).
UPDATE: It looks like the distortion is gone with volume on 50 under software control; not a ideal solution. I hope the hardware volume control is available soon.
UPDATE: The high frequencies do not sound all that well…
UPDATE: It appears that playing CD’s with Mediaplayer via Airplay is very network intensive. Playing directly from my NAS with the RPi sounds a lot better! (but not all that well)
UPDATE: It sounds awful 
It sounds better, but still the depth of the sound is very poor.
Hi i read this post in the bug forum maybe it can help you with the soundproblems enmaybe also the hardware 80 - 100% issue
Pi-dac default volume setting too high (+4db) -> distortion
Postby Woodhouse » Fri Jun 13, 2014 8:40 pm
Great! the 1.4 has finally arrived so I can use my pi-dac at last…
But the default volumesetting is not optimal, especially for the novice user. The output volume of the pi-dac is set to max = +4db bij default. That’s too much and causes distortion on avarage systems.
By loggin in and typing:
sudo amixer -c 0 sset “Playback Digital” 247
You set it at 0db, then all is right.
Additionally when using mpd hardware control, it should somehow be possible to set a maximum that is suitable for a user. Normally that should be 86% or the afore mentioned 247 value rendering 0db.
Perhaps you would consider this, as the current situation might scare of newcomers.
Distortion is still very high. I suspect poor soldering of the 2x4 connector (but then there would be crackling and noise, which is absent) or a damaged DAC (static). I have my amp examined in a few days.
Hi AudiophilePi , yesterday I received my Pi-Dac and can confirm that there is no distortion what so ever in the dac. I hope you you can find and fix the problem quick so you can start enjoying music!!!
grz
Jesse
To be more precise, the s’s and t’s are hissing heavily and thus destroying the stereo image and depth. 44.1khz sounds poor, and 96khz and 192khz don’t sound any better…
In menu playback menu of volumio under Sample rate converter try setting the sinc interpolator to best setting instead of fastest. Hope this helps
That is not possible because the setting is fixed at ‘fastest’.
My mistake i guess it only works when u would want to resample (witch we dont) it looks like a faulty device to me
Gordon from IQaudIO offered me to take a look without additional costs, so I am very pleased with that.