v3 has back RCA (on top of RASPIs USB and LAN) WITH external screen connectors and MANDATORY external 6-7.5v input via DC Jack. This comes as a result of a new presumably better LDO regulator (converts 6/7v to 5v for Raspi power and 3.3 v for the DAC). 76Euros http://www.audiophonics.fr/en/diy-dac/a ... 10657.html
He makes an important point. The DAC converts 0/1 to a 2v signal that our amp will amplify to feed our speakers. If the power supplied to the DAC is shaky that 2v signal produced by the DAC will be bad. So this is why all the "HiFi" DACs have optional (KALI - I Sabre v1 v2 v2.1 - HiFi Berry - Mambo Berry LS DAC+) or mandatory external power connector (I Sabre v3 - Mamboberry HiFi DAC+ [discontinued]). In all cases you only need one power source, the card will feed the Raspi the 5v it needs.
I am not decided yet, but to help others, if you will/or want to spend money on a power supply, i.e. linear power supply or a Ifi wall PSU (https://volumio.org/product/ifi-ipower/) then v2 should do. If you want to plug chinese wall PSU then it should make sense to spend money on the v3 and presumably better LDO.
I am decided on audiophonics, because the KALI people (a major source of snakeoil salesmanship) convinced me on the importance of a good clock to get accurate sampling of the audio, which the Raspi can not provide. They take the route of 2 clocks (1 for 44.1khz [i.e. CD audio] and one for 48khz modern recordings) resample, buffer and feed the DAC board.
Look at their two clocks .
The audiophonics take the one clock route. Look at their clock.
Obviously the Audiophonics is more accurate, I do not know by how much, Kali doesn't give these details, but the TCXO clock misses 1 beat every 2 million (0.5ppm). Regular crystal oscillator move in the 10 - 100ppm range. So although you can't produce exactly 44.1khz with a 50Khz clock, with clock multipliers you can get better accuracy than with two clocks with higher ppm.
This is my contribution as a "Sunday morning expert" that wants to help other fellow Sunday morning expert get the best bang for their hard earned bucks.
First Audiophonics make great hardware. I am a good friend with the founder of the company and kudos for great hardware they are making.
However the post is about clocks. Let me explain the diffrence betwen ppm and jitter.
You see PPM is the long term drift accuracy of the clocks. In audio , we dont care at all about long term (or more precisely it needs to be below 100ppm)
The only thing we care...is jitter. The analog wave is directly made from the clocks taking points every second and approximating the analog output from it (44Khz is 44.000 sampled points per second)
Now jitter...when you have those points that were taken every 40ns (lets say)... jitter will mean that one pint is at 44ns and another at 36ns.You see , how can we make an accurate analog waveform when the points are different than sampled sound ??
It gets more complicated though...its not the jitter...its the phase noise.
So this comments on (Snake oil salesmanship) and such are incorrect. Its math.
At last one more thing on the ESS sabre generally. When you have only one clock for both 44/48Khz audio files...what you do is re sample the file. Its called ASRC. Its not bit perfect but an approximation designed to eliminate jitter (and folks at ess sabre are very good on this). However me personally (and prob others) we care about bit perfect.