Hi Roberto.
The output stage is more elaborate on the r2r 7. And it's class-A.
Good point, quality is of course more than class-A or AB etc but there is little doubt that the R2R 7 should have the edge here. I believe the Soekris approach was to be as minimalistic as possible, which may have other good points.
The r-core transfos provide superior isolation to swiching psus, which can contaminate each other and gears connected to the same circuit. Soft switched supply are much better but i doubt the Meanwells are. On the audio-gd, you have got powerful class-A discrete supplies hence the heatsinks, not such thing on the Soekris.
As with the switching PSUs, it all depends how they are filtered after that. These Mean Wells, are soft switching designs (ZVT) with a 70-80% efficiency, and they have an EMI filter on the power network side, so they should spew back less than conventional, not pre-filtered, hard switching designs. Lynn and many other companies have great designs with switching PSUs. A very good linear PSU may be better in general, of course, and my experience leans towards that as well.
The digital input board features two fpgas to reclock the input signal at over 100Khz, reducing jitter drastically. Not sure the Soekris does this. Maybe.
it does. (not sure about the frequency)
In addition, you get a powerful DSP to perform elaborate oversampling. No such thing on the Soekris.
It does oversampling and applies one of four selectable filters - in a FPGA. It is probably more sophisticated on the R2R 7.
The r2r 7 usb interface is an Amanero, which has better reputation the Xmos boards in the same price range.
Yes and no. Recent Amanero boards do not even properly announce their properties correctly. I have one in a Gustard X20U and computers attached to it believe it can do DSD512 and PCM768, which of course lead only to horrible noise. Can I trust something where the programmers are not able to understand the USB interface? I am going to contribute patches to the linux ALSA subsystem to properly deal with those things.
(And Amanero IS a XMOS board. The Soekis has an XS1-U6A on board (so not a U8 or U208) and they all have the same firmware.
Plus the signal coming out of the usb board gets reclocked very efficiently. The result is a usb input that sounds excellent and that is hard to significantly improve over.
The Soekris reclocks the signal as well.
Connectivity:
Inputs: usb, rj45 i2s, hdmi i2s, coax, bnc, toslink. The difference is the dac1541 has an aes input, but none of the i2s.
Ouputs: balanced, rca, acss. The Soekris lacks the latter.
I have exchanged technical emails with Soeren and he told me he does not believe I2S would bring any advantage since he isolates and rechecks the USB input. It makes sense to me.
ACSS is of course Audio-GD specific. A great invention, indeed, but only relevant if you have other Audio-GD stuff.
That said, i am sure the Soekris is excellent in its price range. Audio-gd gives even more value in my opinion. But i am no expert really. I just love their sound. And looking under the hood. Very impressive.
The R2R 7 looks quite impressive. And since even the little sparrow sounds fantastic for its price, I am sure audio-gd has something that delivers really a lot for the price.
And it should be fantastic. Including customs, German VAT and shipping costs, I would pay 2750 EUR for it. For the Soekris DAC1541 I would shell out 1700 EUR including (danish) VAT and shipping costs. This is more than 1000 EUR less. If there were no obvious difference I would be disappointed
Kingwa would have to release a r2r combo in the same price range for us to compare apples to apples. I am glad to see all these new discrete r2r offerings however. I like the desgin of the Soekris, i.e. the overall layout.
Do you know what? I like the overall layout of the R2R more, but everybody has a budget. I could afford a DAVE, I would notice a minor change on my bank account, but also my wife would kill me so swiftly that, well, I would not even notice it. The R2R 7 would cause major trouble
The Soekris torerable trouble (I would have to buy her an iPhone X and this would probably settle the matter).
Roberto