Cayin RU6: R-2R USB Dongle DAC with Head-Amp
Dec 1, 2021 at 9:11 AM Post #436 of 1,779

Nostoi

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OK, as promised, here are some of the notes I took while listening to RU6 final prototype sample I borrowed recently from Musicteck. And, as the usual disclaimer, this is how I hear it.

Was using RU6 (High Gain, NOS filter) with Traillii and First Times cable (4.4mm) connected to my aging Galaxy S9 (smartphone volume set to max) while streaming Amazon HD (192kHz flacs), volume matched in every comparison.

already shared this picture, but here it is again:
cayin-ru6-x03.jpg

RU6 vs W2 - very similar tonality and sound sig, though RU6 has just a touch more sub-bass rumble. The main difference I hear is in soundstage expansion where RU6 is noticeably wider and has a more holographic 3D imaging. I also noticed RU6 having a little blacker background.

RU6 vs S2 - S2 tonality is a little warmer due to a smoother treble extension in comparison to RU6 having more sparkle in treble and more transparency in mids/vocals. Also, S2 bass is softer with a slightly slower attack while RU6 packs a faster mid-bass punch. Furthermore, RU6 soundstage is wider and background is a little blacker.

Also, no problem driving Meze Audio Empyrean (4.4mm BAL), though tonality was a little brighter and more mid-forward, with bass lacking some punch. Furthermore, was able to drive 470ohm ATH-R70x (from 3.5mm SE), though had to raise the volume to 83. And again, the sound was a little more mid-forward with bass lacking some impact.

With IEMs it seems to be working great connected directly. But with some demanding headphones I hooked up RU6 output directly to C9 while setting RU6 volume to 100. That scaled up the sound without any distortion or artifacts, especially in R70x where the bass came alive and I felt like I was driving these cans to their full potential.

cayin-ru6-x12.jpg
The C9 pairing is interesting. I assume there's no actual line out on the RU6, but doesn't this double amping produce noise with the R2R architecture?
 
Dec 1, 2021 at 9:15 AM Post #437 of 1,779
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The C9 pairing is interesting. I assume there's no actual line out on the RU6, but doesn't this double amping produce noise with the R2R architecture?

No noise that I heard, thus why I mentioned no distortion or artifacts when I tested it with R70x. Correct, no LO in RU6, none of those dongles have dedicated LO, just not enough room. With C9 by itself, I do hear waterfall hissing with sensitive IEMs, but that is irrelevant of analog source I feed into C9 :wink:
 
Dec 1, 2021 at 9:20 AM Post #438 of 1,779

Nostoi

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No noise that I heard, thus why I mentioned no distortion or artifacts when I tested it with R70x. Correct, no LO in RU6, none of those dongles have dedicated LO, just not enough room. With C9 by itself, I do hear waterfall hissing with sensitive IEMs, but that is irrelevant of analog source I feed into C9 :wink:
Good to hear. Because when I paired the R01 with the C9, it really didn't sound good - seem to lose definition and overall coherence. But if the RU6 pairs well, then that's good news.

Awaiting on EU availability. :)
 
Dec 1, 2021 at 9:57 AM Post #439 of 1,779

someyoungguy

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Here's a few thoughts after a day's listening:
  • I love how it remembers the last settings between shutdowns/disconnects. Same volume, gain and mode; no more worrying about blowing my ears out when I reattach a dongle :)
  • OS mode seems to give slightly sharper definition and edges to instruments and notes than NOS mode (as advertised). But even then OS doesn't sound over-etched or too precise or clinical as some sources can. I tending towards preferring OS.
  • To me, low gain with higher volume sounds better than high gain with a lower volume (to achieve the overall same output intensity). I'm using B&W P7s, which are easy to drive over-ear headphones. Although easy to drive I usually use them on a mid-higher gain setting with most sources, as I tend to find higher gain usually suits me better. That's how I've been using the RU6 most of the day. Out of curiosity I tried lower gain this evening and was surprised to find bigger dynamic swings and a better sense of blackness and definition. I've gone back and forth a few times and I swear it can't just be placebo either. Maybe it's something to do with the resistor ladder volume and signal attenuation, but it certainly sounds better to me with lower gain and a higher volume setting.
  • You can really listen quite loud with this thing \m/. Not that I've been purposely trying! But I've ended up unconsciously doing so; those dynamics can really drive up loud without the harshness that usually makes you reach for the volume down button. Fun times.
 
Dec 1, 2021 at 9:58 AM Post #440 of 1,779
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I want to ask about the specification.
Does it need OTG on any side of C -> C cable?

You need OTG cable with RU6. I believe ALL USB Audio device are operated under OTG setting.

on any side? I didn't know we have to differentiate OTG USB cable into one side OTG or two sided OTG. Can someone help me on this?
 
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Dec 1, 2021 at 10:02 AM Post #441 of 1,779
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Xmas just arrived early here is Shanghai :)

Interesting surprise is the case comes with a few of these leather/3M stickers for magnetically attaching the RU6 to something.


Is there a recommended burn in/run in period for the RU6?

Yes, there is a piece of magnet at the back of the protective case.

With reference to R01, First 50 hours makes a lot of different, and the DAC will stable after 100 hours, so please give it a few day before you draw your conclusion, or return the dongle to the seller just in case you don't like it. :wink: :wink: :wink:
 
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Dec 1, 2021 at 10:04 AM Post #442 of 1,779

MarkParity

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You need OTG cable with RU6. I believe ALL USB Audio device are operated under OTG setting.

on any side? I didn't know we have to differentiate OTG USB cable into one side OTG or two sided OTG. Can someone help me on this?
OTG at both ends works fine for me. I see no reason to have OTG at one end only and potentially make the cable directional if an OTG connector is only used at one end and both ends works.
 
Dec 1, 2021 at 10:20 AM Post #443 of 1,779

abitdeef

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I don't know what the purpose of one way interconnects is but 2 of my nicer cables are one way. Woo audio and DD hifi. Always induced panic when I forgot that fact and put them the wrong way around 😀

20211201_101613.jpg
20211201_101529.jpg
 
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Dec 1, 2021 at 11:01 AM Post #444 of 1,779

utdeep

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Is there a way to get this into a mode where it works with devices like the Nintendo Switch? This was an awesome feature of the Lotoo dongles.
 
Dec 1, 2021 at 11:10 AM Post #446 of 1,779

abitdeef

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Having a Dragonfly Cobalt, in your opinion, what difference can there be compared to the RU6?

It's smaller, it's blue, and it's more expensive 😀

Ha ha, couldn't resist. You'll have to wait till someone can compare the two. Not many have the unit yet.
 
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Dec 1, 2021 at 3:14 PM Post #447 of 1,779

SeEnCreaTive

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@Andykong I LOVE how straight up you are. Telling us the difficulties, and the "not particularly impressive" specs. Makes me know that this product was actually designed with real care. I think once my BTR1k finally wears out, this will be right at the top of my list for a replacement (Bluetooth is nice, but I can work around it)

I've always loved the idea of R2R dacs. Such an analog solution to a digital problem. I find them facinating.
 
Dec 1, 2021 at 3:27 PM Post #448 of 1,779

Goofyboy84

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@Andykong

Congratulations ! Nearly half the power of R01 for about 40% of the price. This should be excellent for IEMs and headphones (especially > 100 dB/mW and < 50 ohms)
I have Custom JH Laylas being made as we speak, and I just returned my Audioquest Cobalt and going to buy this RU6. 😊 Just waiting for a couple of things to clear. Laylas are 20 ohm and 117 dB/mW. This should do well for them. My music source is my iPhone 12 Pro Max. I DO have the camera adaptor, so I can convert it to USB and also charge it at the same time. 😊
 
Dec 1, 2021 at 4:41 PM Post #450 of 1,779

CrocodileDundee

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I have Custom JH Laylas being made as we speak, and I just returned my Audioquest Cobalt and going to buy this RU6. 😊 Just waiting for a couple of things to clear. Laylas are 20 ohm and 117 dB/mW. This should do well for them. My music source is my iPhone 12 Pro Max. I DO have the camera adaptor, so I can convert it to USB and also charge it at the same time. 😊
Congrats on both!

From my side, I can say that almost anything can Drive the Laylas quite Loud. :)
 

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