Cayin RU7: 1-Bit Resistor Network Dongle DAC /Amp

[baskingshark]

I've heard no such thing so far, even with IEMs that tend to be brighter. RU7 is the epitome of silky smooth, rich sound. More to come, but just wanted to say it's about as far from harsh as anything I've heard.

+1

 

[Surdzo]

Thanks, yeah my main are the Sony Z1R so in my opinion slightly bright so was/is hoping the RU7 is in between the M15 and RU7, a nice middle ground but I'll see sooner or later

After all reviews written so far I have feel that RU7 is exactly what you say (something in between) but than again until I hear RU7 myself with my gear can’t claim and take it for granted. The biggest problem with hifi/chifi stuff is that there is very a few places in the world where you can actually test the gear and than decide what you really like, therefore we are all condemned to burn more money than necessary and by doing so we make bad impact to our ecosystem and get poorer every next day by playing their games in pursuit of perfection we are all trained and programed to seek our whole live.
So my advice is to outsmart them all and do all research you can, then make decision and play wisely don’t let yourself to ride theirs hype waves.

 

[itwasluck]

I've heard no such thing so far, even with IEMs that tend to be brighter. RU7 is the epitome of silky smooth, rich sound. More to come, but just wanted to say it's about as far from harsh as anything I've heard.

Agreed 100%, just to add to this, if you want even more smoothness, the RU6 would be the one to get. But IMO, the RU7 is able to provide a similar smooth, rich sound (in DSD64 mode) without compromising on the details. Both the RU6 and RU7 are leagues ahead of the M15 IMO.

 

[Polky74]

Thanks, yeah my main are the Sony Z1R so in my opinion slightly bright so was/is hoping the RU7 is in between the M15 and RU7, a nice middle ground but I'll see sooner or later

I must say that between the M15 and the IER-Z1R, which I've been listening to for a while, a "magic" synergy is created in my opinion. The warm character with very evident bass, however, does not allow to obtain the same synergy with the RU6. When the RU7 arrives I'll be able to tell you more, but already with the M15, in my opinion, you have a terrifying match.

 

[Andykong]

Congratulations for the review, also because you have compared it with the most popular dongles at the moment (apart from the W4) and many, including me, were waiting for this comparison. Now that you've listened to it well, could you explain to me what changes, while listening, by modifying the values between 64-128-256 of the "all to DSD" function. Last question is it a function that can be disabled or is the minimum 64? Thank you.

Yep the minimum is DSD64.

I can't really tell much difference between DSD 128 and 256, but the DSD 64 is a tinge less sharp in edge definition/imaging and soundstage. It is quite subtle, and you need to do A/B listening multiple times with resolving gear in a quiet room and pay very close attention.

HeadFi is updating its search index, so I can't quote my previous writing on this subject. I probably will write a more detail post on the All-to-DSD feature later on, but right now, let's go through this briefly.

The 1-Bit resistor network can only accept 1-bit bitstream as input, therefore we need to convert all non-1-bit audio signals into 1-bit before we can feed the source material from USB Audio to our 1-bit Resistor Network. This is where ALL-TO-DSD kicks in. In other words, if you are listening to anything that is NOT 1-bit, regardless of whether the material is stored in your local TF card or you are streaming via your subscribed service, it must be converted to DSD (i.e., 1-bit format), so DSD-64 is the default setting, and you can select DSD128 and DSD256 if your pairing is permitted. Fortunately, the conversion from PCM-to-DSD is a fairly simple and accurate algorithm, when compared to DSD-to-PCM conversion, and please don't judge PCM-to-DSD conversion based on your DSD-to-PCM experience, they are not the same algorithm in reverse.

Regarding DSD64 vs DSD128 vs DSD256, I won't assume the higher conversion is always the better. The upscaling involves an interpolation algorithm, which means they might enhance the sharpness and sense of resolution, but might compromise the naturalness of the playback. I personally prefer DSD64 with regular 44.1/48 material and DSD128 with 88.2/96 material, in other words, I am a believer of less is more when come to upscaling.

Besides draining more power, are these All-to-DSD setting providing audible differences? Yes but depends. If you are using the Dongle DAC on the go, traveling underground or by bus, or walking on a street, I don't think the difference really matters. If you are using it for critical listening with a decent resolving IEM, then you probably won't hear the difference immediately, but when you compare them after multiple ABABA , you are training your ear to look for the difference, and once you learn the tricks, the difference is fairly audible, and as I said, please don't assume DSD245 is always better then DSD64, not to every pair of ears, and not to every genre of music, IMHO.

 

[Polky74]

HeadFi is updating its search index, so I can't quote my previous writing on this subject. I probably will write a more detail post on the All-to-DSD feature later on, but right now, let's go through this briefly.

The 1-Bit resistor network can only accept 1-bit bitstream as input, therefore we need to convert all non-1-bit audio signals into 1-bit before we can feed the source material from USB Audio to our 1-bit Resistor Network. This is where ALL-TO-DSD kicks in. In other words, if you are listening to anything that is NOT 1-bit, regardless of whether the material is stored in your local TF card or you are streaming via your subscribed service, it must be converted to DSD (i.e., 1-bit format), so DSD-64 is the default setting, and you can select DSD128 and DSD256 if your pairing is permitted. Fortunately, the conversion from PCM-to-DSD is a fairly simple and accurate algorithm, when compared to DSD-to-PCM conversion, and please don't judge PCM-to-DSD conversion based on your DSD-to-PCM experience, they are not the same algorithm in reverse.

Regarding DSD64 vs DSD128 vs DSD256, I won't assume the higher conversion is always the better. The upscaling involves an interpolation algorithm, which means they might enhance the sharpness and sense of resolution, but might compromise the naturalness of the playback. I personally prefer DSD64 with regular 44.1/48 material and DSD128 with 88.2/96 material, in other words, I am a believer of less is more when come to upscaling.

Besides draining more power, are these All-to-DSD setting providing audible differences? Yes but depends. If you are using the Dongle DAC on the go, traveling underground or by bus, or walking on a street, I don't think the difference really matters. If you are using it for critical listening with a decent resolving IEM, then you probably won't hear the difference immediately, but when you compare them after multiple ABABA , you are training your ear to look for the difference, and once you learn the tricks, the difference is fairly audible, and as I said, please don't assume DSD245 is always better then DSD64, not to every pair of ears, and not to every genre of music, IMHO.

Thanks for the reply... so with my 16/44 flacs I leave it at 64 and everything is ok... if instead I listen to something like Amazon HD with higher resolutions I might prefer 128 or 256. If I understand correctly.

 

[CT007]

RU7 has more resolution/shimmer/detail contrast than M15 right out of the box? I am a bit surprised by that.

MP3 "stutters and clips with RU7, every time, on any DSD setting"? Is this only applicable to MP3? or sutter happens with regular 16/44.1 or 24/96 lossless FLAC as well? May I know what IEM/headphone were used? Volume and gain setting? This will provide a more informative guideline to steer customers away if they need to operate the RU7 in similar condition.

Yes, fresh RU7(MusicTeck), and slightly used M15(bought new on Amazon).

Tested with AFUL Performer5

The stuttering occurs under these conditions:
- Android phone (Pixel 5a)
- RU7: any DSD; any gain; PO mode; volume ~32; 3.5mm or 4.4mm jack
- Stutters/drops occur at same, multiple locations in song
- RU7 display says "48KHz"
- Track is MP3 VBR ~178kbps 44.1 joint stereo
- Player is the standard/stock one installed with the Android OS

Played with VLC = same result.
Played in Telegram = same result.
Played from PC with WinAmp = same result.
Played from PC with WinAmp, forcing device from 32bit/48 to 32bit/44.1 = same result.

So far, this is the only track I've found that drops, but I will keep searching some more and post if I find more.

 

[itwasluck]

HeadFi is updating its search index, so I can't quote my previous writing on this subject. I probably will write a more detail post on the All-to-DSD feature later on, but right now, let's go through this briefly.

The 1-Bit resistor network can only accept 1-bit bitstream as input, therefore we need to convert all non-1-bit audio signals into 1-bit before we can feed the source material from USB Audio to our 1-bit Resistor Network. This is where ALL-TO-DSD kicks in. In other words, if you are listening to anything that is NOT 1-bit, regardless of whether the material is stored in your local TF card or you are streaming via your subscribed service, it must be converted to DSD (i.e., 1-bit format), so DSD-64 is the default setting, and you can select DSD128 and DSD256 if your pairing is permitted. Fortunately, the conversion from PCM-to-DSD is a fairly simple and accurate algorithm, when compared to DSD-to-PCM conversion, and please don't judge PCM-to-DSD conversion based on your DSD-to-PCM experience, they are not the same algorithm in reverse.

Regarding DSD64 vs DSD128 vs DSD256, I won't assume the higher conversion is always the better. The upscaling involves an interpolation algorithm, which means they might enhance the sharpness and sense of resolution, but might compromise the naturalness of the playback. I personally prefer DSD64 with regular 44.1/48 material and DSD128 with 88.2/96 material, in other words, I am a believer of less is more when come to upscaling.

Besides draining more power, are these All-to-DSD setting providing audible differences? Yes but depends. If you are using the Dongle DAC on the go, traveling underground or by bus, or walking on a street, I don't think the difference really matters. If you are using it for critical listening with a decent resolving IEM, then you probably won't hear the difference immediately, but when you compare them after multiple ABABA , you are training your ear to look for the difference, and once you learn the tricks, the difference is fairly audible, and as I said, please don't assume DSD245 is always better then DSD64, not to every pair of ears, and not to every genre of music, IMHO.

Very interesting to see the all to DSD conversion work so well, I have had limited time with the RU7 but so far no audio artifacting whatosever in whatever source I used. I also tend to prefer DSD64, it sounds the most analogue to me. DSD128 and up seems to have a bit more detail and I can see how more interpolation can do that to the sound!

I feel the RU7 strikes a great balance between R2R and delta-sigma DACs, it sounds natural and smooth like an R2R but retains the details you would get from a traditional delta-sigma DAC. That's a win-win in my book!

 

[CT007]

Agreed 100%, just to add to this, if you want even more smoothness, the RU6 would be the one to get

I see RU6 as the silky smooth, rich one. RU7 as the more technical, punchy, detailed one. Small difference, but noticeable enough of one where I prefer that more smooth, lower fatigue prominence RU6 has. M15 is flatter/thinner sounding, but I think slightly softer on treble detail/resolution than RU7.

 

[itwasluck]

I see RU6 as the silky smooth, rich one. RU7 as the more technical, punchy, detailed one. Small difference, but noticeable enough of one where I prefer that more smooth, lower fatigue prominence RU6 has. M15 is flatter/thinner sounding, but I think slightly softer on treble detail/resolution than RU7.

I was really surprised to see how punchy the bass can get on the RU7, its not that far off from my desktop setup which is insane! Most of my stuff are (dark) non-fatiguing to begin with so the RU7 compliments them quite well. If I were using more neutral sounding HPs/earbuds, I'd definitely prefer the RU6 as well.

 

[Andykong]

Yes, fresh RU7(MusicTeck), and slightly used M15(bought new on Amazon).

Tested with AFUL Performer5

The stuttering occurs under these conditions:
- Android phone (Pixel 5a)
- RU7: any DSD; any gain; PO mode; volume ~32; 3.5mm or 4.4mm jack
- Stutters/drops occur at same, multiple locations in song
- RU7 display says "48KHz"
- Track is MP3 VBR ~178kbps 44.1 joint stereo
- Player is the standard/stock one installed with the Android OS

Played with VLC = same result.
Played in Telegram = same result.
Played from PC with WinAmp = same result.
Played from PC with WinAmp, forcing device from 32bit/48 to 32bit/44.1 = same result.

So far, this is the only track I've found that drops, but I will keep searching some more and post if I find more.

So this happens on Android and Windows PC, but not all MP3s are having the same shuttering problem, only with this particular song? Have tried other MP3 tracks? Do you encounter a similar problem? I am not challenging your observation, apparently, I have a different perception when I read your initial complaint about shuttering, so I want to clarify the problem you have run into.

 

[ducnsh]

HeadFi is updating its search index, so I can't quote my previous writing on this subject. I probably will write a more detail post on the All-to-DSD feature later on, but right now, let's go through this briefly.

The 1-Bit resistor network can only accept 1-bit bitstream as input, therefore we need to convert all non-1-bit audio signals into 1-bit before we can feed the source material from USB Audio to our 1-bit Resistor Network. This is where ALL-TO-DSD kicks in. In other words, if you are listening to anything that is NOT 1-bit, regardless of whether the material is stored in your local TF card or you are streaming via your subscribed service, it must be converted to DSD (i.e., 1-bit format), so DSD-64 is the default setting, and you can select DSD128 and DSD256 if your pairing is permitted. Fortunately, the conversion from PCM-to-DSD is a fairly simple and accurate algorithm, when compared to DSD-to-PCM conversion, and please don't judge PCM-to-DSD conversion based on your DSD-to-PCM experience, they are not the same algorithm in reverse.

Regarding DSD64 vs DSD128 vs DSD256, I won't assume the higher conversion is always the better. The upscaling involves an interpolation algorithm, which means they might enhance the sharpness and sense of resolution, but might compromise the naturalness of the playback. I personally prefer DSD64 with regular 44.1/48 material and DSD128 with 88.2/96 material, in other words, I am a believer of less is more when come to upscaling.

Besides draining more power, are these All-to-DSD setting providing audible differences? Yes but depends. If you are using the Dongle DAC on the go, traveling underground or by bus, or walking on a street, I don't think the difference really matters. If you are using it for critical listening with a decent resolving IEM, then you probably won't hear the difference immediately, but when you compare them after multiple ABABA , you are training your ear to look for the difference, and once you learn the tricks, the difference is fairly audible, and as I said, please don't assume DSD245 is always better then DSD64, not to every pair of ears, and not to every genre of music, IMHO.

Based on your explanation, I think it is good if there is a user-choosable "Auto conversion" feature that automatically converts 44.1/48 to DSD64, 88.2/96 to DSD128, ...

 

[Polky74]

Based on your explanation, I think it is good if there is a user-choosable "Auto conversion" feature that automatically converts 44.1/48 to DSD64, 88.2/96 to DSD128, ...

It probably also depends on the type of music you listen to (if more structured or not) so it's best to leave the decision to the user. In addition to this, by intervening sensitively on consumption, it could always be better to use the 64 when on the move.

 

[ducnsh]

It probably also depends on the type of music you listen to (if more structured or not) so it's best to leave the decision to the user. In addition to this, by intervening sensitively on consumption, it could always be better to use the 64 when on the move.

Yes, it is the reason that I state that this feature should be "user-choosable" to let the user decide on each circumstance, I think it is a useful feature ...

 

[Andykong]

Based on your explanation, I think it is good if there is a user-choosable "Auto conversion" feature that automatically converts 44.1/48 to DSD64, 88.2/96 to DSD128, ...

It probably also depends on the type of music you listen to (if more structured or not) so it's best to leave the decision to the user. In addition to this, by intervening sensitively on consumption, it could always be better to use the 64 when on the move.

Yes, we can do that with DAP, because we have a MCU to process rule-based feedback instruction after input data analysis.

With RU7 and RU6, the so-called MCU is only responsible for collecting control button action and feeding back a signal to the LED screen. In these devices, there isn't any feedback-based (or IF-THEN-ELSE condition) that will analysis the content and act accordingly we assume your mobile phone is responsible for all the brain work.

If you want a smart-device user experience, maybe you should consider a DAP instead.