[Andykong]

So, I have been focusing lately more on cables and current draw rather than the sound, especially with iPhone where we have a current limitation. ClieOS kindly shared his measurements, and I confirmed that with all the IEMs and Headphones I tried connected to 4.4mm output, in High Gain, I get:

• DSD256: 220 mA
• DSD128: 190 mA
• DSD64: 170 mA

One thing to note, once you are idling, no playback, the current drops to 50mA so you are not draining your phone's battery as much. This is a very good design practice!

For the reference, the volume level under these conditions:

w/UM Mentor Multiverse: v26
w/Elysian Annihilator'23: v39
w/Meze Empyrean: v43
w/ATH-R70x (470ohm, 99dB sensitivity): v65

R70x are my most demanding headphones, and even with iPhone XS and RU7 in high gain and DSD256, I was able to listen to R70x at 65 without any stuttering; could even push the volume higher.

But, I was still trying to force it into a stuttering condition with iPhone, to hit the current draw limit. Was only able to do that with Empyrean in high gain at DSD256 while pushing the volume beyond listening level when I raised it to 63 and current draw hit 230mA. Again, just running the experiment because we use different demanding headphones. Under this condition, once I drop to DSD64, problem goes away since it draws less current.

Another solution where you don't have to compromise switching to a different DSD format is to switch to a different cable. Tried my new @ddHiFi MFi07S and even at high gain, with DSD256, and ear shattering volume with Empyrean, the problem went away once I switched to that cable. I just assume, thicker power wires, less resistance, smaller voltage drop, and just below the threshold of current draw limit which made iPhone happy. Btw, absolutely beautiful cable with high build quality.

So, just in case if someone runs into a problem with their iPhone while listening to RU7 in high gain and DSD256, and you are driving your demanding headphones at a high volume, switching to a different cable is one of the solutions if you don't want to drop it down to DSD64. In my case, ddhifi MFi07S usb-c to lightning OTG cable did the trick!

Thank you very much for trying out different cable and charging combinations for RU7, this is very helpful to our users. I just added this response to the FAQ of RU7.

Maybe we should adopt a different set of names for the All-to-DSD modes. DSD64 becomes Standard, DSD128 becomes Turbo, and DSD256 becomes Insane. With these names, users won't be surprised that the DSD256 is not operable in certain conditions.

 

[Andykong]

How many hours does it take to burn it in? What changes should happen?

If you are reading this thread, you probably have come across several users' impressions regarding the changes they experienced. As a sponsor, I normally leave subjective assessments of my products to users and reviewers, to avoid conflict of interest.

Burn-in is not meant to be an exact "snap-shot" condition. There is no such thing as you need to burn in your Dongle DAC or DAC for X hours before you can hear it. Or if you burn in your Dongle DAC for X-1 hours, you have failed the burn-in process. The simplest method, IMHO, is to connect your RU7 to your computer and keep it running for 2 days, that should do the job already. Just loop through some non-stop music from youtube in the background or whatever music file you have. It doesn't matter what load you are using, as long as RU7 won't enter idle mode, you are in business. This should be fairly straightforward, almost free of charge, and hardly create the illusion that we are convincing our users to spend more time with the Dongle DAC to get used to it.

Yes, some users are convinced that they can hear the difference even after 100 hours, but that does not contradict my suggestion. Neither does someone who believes they don't hear any difference after 1 hour. However, I do agree that burn-in won't change a bad device to a good device, but audiophiles are devoted to pursuing the last few percent of performance, aren't we? So 1% improvement is a huge improvement if we are struggling from 90% to 95%, but 1% improvement means nothing if we widen our base line to consumer electronic and wokign on a range of 40% to 90%.

 

[Click]

Review of the RU7 from another Andy:

 

[Patlezinc]

Line out seems crazy. I hope to get mine soon.

 

[Andykong]

RU7 is insanely addicting, I can't stop using it! I honestly never thought a dongle could ever compete with desktop setups but here we are, the RU7 has a larger soundstage than my RME+THX and is a lot more organic (no surprise there). The RU7 is revolutionary for being the only portable 1-bit DAC and packs a lot of power too!

Speaking of warm up time, have you timed the RU7? I know the RU6 can take some time to settle in.

From what you described, I assume you are very happy with your RU7. "Insanely addicting" is very strong and supportive feedback from a user, and this is the kind of encouragement that makes our day. Thank you.

"Portable" can be a qualifying description that means different sizes/weights to different people and application scenarios. As far as Cayin is concerned, RU7 is our second "portable 1-bit DAC and packs a lot of power", and N7 DAP is our first portable 1-bit DAC implementation. The 1-bit resistor ladder DAC in RU7 is incurred from N7 directly. We couldn't have developed this DAC circuit for RU7, the project won't justify that. In other words, without N7 DAP, there won't be RU7 Dongle DAC.

 

[Andykong]

Anyways, now am 1.5 weeks with the RU7, and so far I haven't found any stuttering, but I mainly use FLAC/WAV files, no mp3s.

The RU7 really pairs well with the Sennheiser HD650 (high gain, 4.4mm). Great lush vocals.










The AFUL Performer 5 isn't a neutral IEM, it is quite coloured with a big subwoofer like sub-bass. Yep, find it a bit thicker in note weight and on the warmer side of the equation tonally, yeah so it isn't that bright/sharp sounding.

We have tested the RU6 and RU7 with 300Ohm headphones, the extra power delivered by the parallel amplification circuit of RU7 definitely works better than RU6 in this pairing. While we find the RU7 + HD650 combo very enjoyable with certain genres of music, it won't open up the HD650 when called for, and the dynamic is compressed with OST or orchestral music. Yes, I agree that RU7 is amazing and I was shocked (both at price-performance and size-performance) when I heard RU7 with full-size headphones for the first time, but I would like to put RU7 into the right context, not just for the Dongle DAC market segment, but also for the generalized portable market.

 

[jsmiller58]

We have tested the RU6 and RU7 with 300Ohm headphones, the extra power delivered by the parallel amplification circuit of RU7 definitely works better than RU6 in this pairing. While we find the RU7 + HD650 combo very enjoyable with certain genres of music, it won't open up the HD650 when called for, and the dynamic is compressed with OST or orchestral music. Yes, I agree that RU7 is amazing and I was shocked (both at price-performance and size-performance) when I heard RU7 with full-size headphones for the first time, but I would like to put RU7 into the right context, not just for the Dongle DAC market segment, but also for the generalized portable market.

@Andykong I just want to say that I continue to be impressed by, and very much appreciate, your direct, balanced, and honest perspectives about your own products. I have both the RU6 and RU7 and thoroughly enjoy them. Based on the character you display, and the proficiency of your products, I can wholeheartedly say I will continue to be your customer well into the future, and consider your much higher end offerings!

 

[twister6]

It's a long detailed read, but everything is partitioned so will be easy to follow. Enjoy my review of Cayin RU7

 

[gLer]

It's a long detailed read, but everything is partitioned so will be easy to follow. Enjoy my review of Cayin RU7

Great review as always Alex. We need to chat about those 'warm W4 mids' over a beer one day.

 

[Andykong]

Hi folks,

Just got my RU7 today. Sorry if I’m repeating anything, but I’ve tried searching this thread and reading a bunch of pages to catch up, and I didn’t find an answer after about 45 min, so I’m asking

I’m a little disappointed because I can’t get sound from my iPhone with this dongle at all. I currently have 2 OTG cables, the FiiO LT-LT1 and the one that came with my L&P W4 and neither worked for this. I tried all 3 DSD sampling rates, high and low gain, and I tried Roon ARC and Qobuz. I’m using Sennheiser IE600 on balanced connection. On iPhone, the Roon ARC app recognizes it by name, so there’s at least some sort of communication, and it reports that it is transmitting “lossless.” I tried a variety of PCM 44.1 / 16 and 24 as well as a couple of DSD files, and no luck. It works when connected to my gaming PC by USB-C, but if I keep this DAC it will be to use with the iPhone. The sound was not great for PCM in my very short session trying it on the PC, but that PC is an electrically noisy monster, so I want to try this out in its intended use case before judging.

Any thoughts on getting this to work? Should those OTG cables work? They both work for the Questyle M15, Shanling UA3, and L&P W4. I am willing to order a different OTG cable to give this dongle a fair shot, as I generally like DSD, and I’m more into how it sounds than how it measures. Not sure how to determine if a cable is adequate for the RU7, but this also makes me wonder if this will be a severely battery draining device If it is requiring a cable that will allow for higher power draw than those. I may also be totally ignorant and misunderstanding this, so any correction or suggestions are appreciated!

I believe we have discussed this issue several times, unfortunately, there is never "enough" exposure to this very misleading concept.

Any 5V lightning-to-USBC adapter cable will work well with RU7 (or RU6). If your Cayin dealer didn't stock the CS-L2C cable, you can look for other lightning to USB-C adapter cable but please make sure the cable can support 5V transmission.

This is because a lot of adapter cables were designed primarily for battery charging and data transfer, and they adopt 3.3V as the common standard, which is more than good enough from their perspective. Our Dongle DAC will drain more power than regular data transfer and battery charging, so the standard 3.3V cable is not working, you need to go with lightning to USB-C adapter cable with higher specification, 5V to be specific. To complicate things further, some Dongle DAC are less demanding in power consumption and they can work with standard 3.3V lightning-to-USBC adapter cable, hence creating more confusion for new users.

If you can't find any reference to the voltage capability in the description of the lightning-to-USBC adapter cable, you better check out with the manufacturer for more information. For the record, even Cayin didn't specify 5V on our CS-L2C cable product page, so I am not surprised that this is not mentioned by other cable suppliers, you just have to ask for that piece of information.

So I dug out the MFi06 cable and tried with the Cayin-supplied USB-A to C adapter and USB-C cable. No dice - phone didn’t even recognize anything was connected. But… I totally forgot I even owned a ddHiFi TC28i Pro, and it totally works! It’s funny, I never got that thing to work right with other dongles in the past, and just for laughs I tried the L&P W4 with it, and it doesn’t work for that one, but for the RU7, it’s doing it! Right off the bat, this thing sounds interesting and different… It’s immediately clear that it sounds better on the DSD 256 mode - harshness absolutely reduced. Seems to be able to get plenty loud without dropouts on the IE600 IEMs with this setup. Looks like it will need some time to warm up based on what others are saying, so I’ll let the music play and look forward to watching this dongle open up!

Lol! Unfortunately I have sold my portable soul to the Apple ecosystem… “It just works” unless you have a fancy dongle or anything else not made by Apple

Glad it finally works out for you, the TC28i Pro is a wonderful accessory for high-power Dongle DAC, I have recommended this adapter several times in RU7 thread.

Well, we sure don't want it to be as complicated as this, but "the: company you sold your portable soul to, has indeed created a lot of hurdles in due course of protecting the vested interest of their ecosystem. While some users are looking forward to the replacement of the lightning connector with USB-C in the near future, I am not optimistic about that and assume the certification requirements will be further enhanced.

 

[Polky74]

It's a long detailed read, but everything is partitioned so will be easy to follow. Enjoy my review of Cayin RU7

Great review!!! May I ask which DSD decoding you prefer with the Jewels? Thank you.

 

[twister6]

Great review!!! May I ask which DSD decoding you prefer with the Jewels? Thank you.

Dsd128 was my personal preference. Always good to have choices!

 

[Andykong]

You know its funny you say that, I am highly considering ditching my desktop setup as well. I am interested in hearing what a fully unrestricted 1-Bit DAC implementation sounds like. I believe Cayin may make one such solution in the near future but there are definitely some available on the market already. And yes the Arya's are definitely hard to drive but are you using the balanced output?

If you are interested in trying out a desktop 1-bit DAC, the lower cost option is to look for one of those 1-bit based Philips or Marantz CD or SACD players. The Philips TDA1547 1-Bit DAC chip first appeared in Marantz CD11LE back in 1989, and for the next 10 years, there were quite a lot of 1-Bit-based CD players from Philips and Marantz. Since SACD was announced in 1999, so 1-Bit DAC was roughly 10 years older than the DSD format. Last but not least, the current Marantz flagship SACD player SA-10 is based on their pure 1-bit DAC circuit, and the SA-10 is equiped with

Modern desktop DAC tends to be fairly high-end, examples are T+A DAC 8, PS Audio Directstream /DirectStream Junior, AAVIK C-300, Signalyst DSC-1, Audiobyte Hydra Vox, Lampizator DSD, .... If you have a deep pocket, basically any DAC from Playback Design, EMM Lab and Mola Mola will also serve the purpose.

Cayin doesn't have any desktop 1-bit DAC product in the pipeline. Cayin N7 line out or pre-out connecting to a home audio system is one of the cheapest 1-bit DAC solutions in the market right now, but that is not a desktop device and is not appropriate to use as a desktop replacement, but for trail and exploration, that can be a decent option.

 

[itwasluck]

If you are interested in trying out a desktop 1-bit DAC, the lower cost option is to look for one of those 1-bit based Philips or Marantz CD or SACD players. The Philips TDA1547 1-Bit DAC chip first appeared in Marantz CD11LE back in 1989, and for the next 10 years, there were quite a lot of 1-Bit-based CD players from Philips and Marantz. Since SACD was announced in 1999, so 1-Bit DAC was roughly 10 years older than the DSD format. Last but not least, the current Marantz flagship SACD player SA-10 is based on their pure 1-bit DAC circuit, and the SA-10 is equiped with

Modern desktop DAC tends to be fairly high-end, examples are T+A DAC 8, PS Audio Directstream /DirectStream Junior, AAVIK C-300, Signalyst DSC-1, Audiobyte Hydra Vox, Lampizator DSD, .... If you have a deep pocket, basically any DAC from Playback Design, EMM Lab and Mola Mola will also serve the purpose.

Cayin doesn't have any desktop 1-bit DAC product in the pipeline. Cayin N7 line out or pre-out connecting to a home audio system is one of the cheapest 1-bit DAC solutions in the market right now, but that is not a desktop device and is not appropriate to use as a desktop replacement, but for trail and exploration, that can be a decent option.

Thank you for the info and clarification! I was actually looking at the HydraVox but its an FPGA implementation, I ended up ordering the Gustard R26 instead. I been really happy with the RU7 honestly I am still astonished at how well this thing performs. The RU7 made me realize that measurements aren't everything, previously I was chasing gear with better and better measurements but to no avail. This little dongle is more enjoyable to listen to than my actual desktop setup so I ended up selling all my delta-sigma gear. I will try R2R for now (external clock + R26 is pretty close to May levels of staging) and maybe step up to 1-bit in the future.

But for now, I have something I can easily recommend to friends and family that doesn't break the bank, is portable, and sounds amazing.

 

[daijobudes]

With RU7 and Yatono I get completely black background, cleaner sound overall.
If I were to compare RU7 with other sources, I would say first of all, sense of enhanced musical experience is there, two major Factors: Dimensional and Spatial, that allows music to be represented in a more Hifi experience with better quality of recording even on old recordings. That is very DSD like!
My other source DX320X is more forward, less dimensional and spatial, on RU7 I get a more relaxed music listening.