New Audio-gd R-7, R-7HE R-8, R-27, R-27HE, R-28 Flagship Resistor Ladder DACs and DAC/amps
Sep 4, 2017 at 10:28 AM Post #301 of 11,259
+2
Value for money at this price, great for a alternative setup.
I ll put my Money on its bigger brother pending further developments.
.

Still, R2R11 looks promising to say the least. I'm tempted to give this critter a try.
 
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Sep 11, 2017 at 10:50 AM Post #304 of 11,259
The point is better PSUs, output stage, input interface, signal processing, chassis, connectivity, reputation, etc...

PSU: Medical grade switching PSUs (like those in the Soekris) are not worse than using transformers. In fact, the latter may irradiate more EM inside the chassis and that's why companies like Audio-gd and Gustard often put walls inside the chassis. If you put good filtering and good regulators after the PSU, you cannot observe difference.

Output stage: it is all to be determined, we do not know yet. The headphone output stage of the Soekris is just a diamond follower, if well implemented it is very neutral.

Input interface. XMOS based in both cases, IIRC? Also, the inputs in the Soekris are all transformer isolated.

Chassis: yep, the Soekis one is a bit on the "industrial design" side.

Connectivity. The Audio-gd may have more, I do not know.

Reputation: Soekris has an astounding reputation with their R2R modules.

Both companies are very careful with their pricing, so it may as well be that the Audio-Gd sounds better. But I would not discount the DAC1541 so easily.

Roberto
 
Sep 11, 2017 at 11:16 AM Post #305 of 11,259


PSU: Medical grade switching PSUs (like those in the Soekris) are not worse than using transformers. In fact, the latter may irradiate more EM inside the chassis and that's why companies like Audio-gd and Gustard often put walls inside the chassis. If you put good filtering and good regulators after the PSU, you cannot observe difference.
Output stage: it is all to be determined, we do not know yet. The headphone output stage of the Soekris is just a diamond follower, if well implemented it is very neutral.
Input interface. XMOS based in both cases, IIRC? Also, the inputs in the Soekris are all transformer isolated.
Chassis: yep, the Soekis one is a bit on the "industrial design" side.
Connectivity. The Audio-gd may have more, I do not know.
Reputation: Soekris has an astounding reputation with their R2R modules.
Both companies are very careful with their pricing, so it may as well be that the Audio-Gd sounds better. But I would not discount the DAC1541 so easily.

Roberto

Putting aside the technical aspects I can tell you from personal experience the Soekris does sound ok but in no comparison with the R2R7. Its my personal opinion and please realize the DAC1541 is 40% of the price of a R2R 7.
I wasn't really attracted to the sound with the DAC1541. Again; its my personal opinion.
 
Sep 11, 2017 at 11:29 AM Post #306 of 11,259
And that's still discrediting the R2R11. That'd be a fairer comparison and I'd bet it might still lose to that. Not because Soekris sucks but because the Agd unit rocks the socks
 
Sep 11, 2017 at 11:50 AM Post #307 of 11,259
Putting aside the technical aspects I can tell you from personal experience the Soekris does sound ok but in no comparison with the R2R7. Its my personal opinion and please realize the DAC1541 is 40% of the price of a R2R 7.
I wasn't really attracted to the sound with the DAC1541. Again; its my personal opinion.

And this is perfectly fine of course. Also, if the DAC1541 is 40% of the price of the R2R7 the latter should sound better, or something really wrong happened! (However, I believe the discussion was about the R2R11)

Roberto
 
Sep 11, 2017 at 5:38 PM Post #310 of 11,259


PSU: Medical grade switching PSUs (like those in the Soekris) are not worse than using transformers. In fact, the latter may irradiate more EM inside the chassis and that's why companies like Audio-gd and Gustard often put walls inside the chassis. If you put good filtering and good regulators after the PSU, you cannot observe difference.

Output stage: it is all to be determined, we do not know yet. The headphone output stage of the Soekris is just a diamond follower, if well implemented it is very neutral.

Input interface. XMOS based in both cases, IIRC? Also, the inputs in the Soekris are all transformer isolated.

Chassis: yep, the Soekis one is a bit on the "industrial design" side.

Connectivity. The Audio-gd may have more, I do not know.

Reputation: Soekris has an astounding reputation with their R2R modules.

Both companies are very careful with their pricing, so it may as well be that the Audio-Gd sounds better. But I would not discount the DAC1541 so easily.

Roberto
Hi Roberto.

The output stage is more elaborate on the r2r 7. And it's class-A. 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.

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. In addition, you get a powerful DSP to perform elaborate oversampling. No such thing on the Soekris. The r2r 7 usb interface is an Amanero, which has better reputation the Xmos boards in the same price range. 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.

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.

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.

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.
 
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Sep 12, 2017 at 5:49 AM Post #311 of 11,259
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
 
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Sep 12, 2017 at 11:05 PM Post #312 of 11,259
ACSS is of course Audio-GD specific. A great invention, indeed, but only relevant if you have other Audio-GD stuff.

Or Krell gear. It's simply current, rather than voltage transmission.
 
Sep 13, 2017 at 1:58 AM Post #313 of 11,259
Looking forward to the outcome of the comparison, if it occurs. The r2r 7 is more analog than the M7. It's a good indication.

I'm at 588 hours (according to my google sheet!)
When I read about something getting a unanimous reception in a magazine I assume it's basically an advertisement and not an objective review.
Well I've had a number of audiophiles over and so far it's been all praise -- not a single point of criticism, and these guys don't share the same ideals for dialing in a system.

3 weeks ago Qingwa told me I should try his "smooth" FPGA firmware. I dragged my feet for a while before getting an $8 "USB Blaster" off ebay. I downloaded the Intel/Altera software, gave audio-gd my TeamViewer ID+pin, and within a couple minutes somebody from China remoted into my computer and flashed my DAC. Prior to this firmware I've been listening via a class A/B Primare i30. I also have a very energetic class-D T+A Power Plant. Using Teac DACs I could handle about 20min of the T+A. Using the R2R7 (original firmware) I could go over an hour. With this smooth firmware I can listen to the T+A for days without succumbing to fatigue or boredom -- a real balancing act. So a minty Primare is retreating into it's packaging while a beat up T+A is taking center stage.

This weekend I was loaned that direct heated triode tube dac (draws 79watt) and yeah it's special in many regards. But if I dial down the tube DAC's volume pot to match gain with the R2R7, a casual listener would not hear the difference when fast A/B switching (usb interface sending I2S to R2R7 and coax to tube dac). Critical listening would detect longer notes from the tubes, mids penetrating with a bit more substance, and a stronger thump to the bass. There is a color about it that does a wonderful job of dressing up simple audiophile tracks -- something you could do without when listening to Infected Mushroom or Major Lazer. Switching back to the R2R7 you detect superior speed and texture, like a modern sabre implementation but absent of fatigue -- surprising given how bright my USB cable chain is (24" Locus Axis usb cable => iFi USB3.0 => 7" Curious USB)

next up I want to hear how the class D Job INT will pair with the R2R7
 
Sep 13, 2017 at 3:07 AM Post #314 of 11,259
I know there is a big price gap between Dave and r2r-7, but since both are using FPGA for sound processing, I would like a comparison. Then again I think the chance a person has both the dave and r2r-7 is quite small...
 

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