[Andykong]

Thanks for refreshing our memories!
I think it explains why using a USB filter with the RU6 has a noticeable impact on sound quality.

If I understood your detailed explanation on 1bit DAC circuits correctly, the impact of such devices should be even greater on RU7. Considering RU7 offers a share line out, it's going to be a very suitable and affordable candidate to be used as a desktop pure DSD DAC.

I believe the 1-Bit DAC circuit is more forgiving than the R-2R DAC circuit in terms of incoming data integrity, so the RU6 probably will be more benefit in comparison.

 

[Daiyama]

Out of the mobile devices I have tested, I'll recommend the USB output from iPad Pro. DAP probably will offer an even better USB audio quality, but most DAPs can offer comparable if not better playback quality on their own, so it kind of defeats the purpose if we use that as a reference point in the Dongle DAC discussion.

Thanks, that is right a dongle out of a DAP seems a bit strange.
Do you happen to know if there are differences in USB output between different ipad types, as I have not an iPad pro, only an iPad 5th gen.

 

[Daiyama]

So my iPad 5th gen is not the optimal fit.
When using the RU6 with my HE1000V2 (ai know a bit of a stress test), at around 55 volume level, the RU6 is turned of, listening volume is very low. For inears it’s fine.
With the M11 I can go up to 98 (above 88 I had to take the headphone of), only at 99 and 100 a stutter starts. On the other hand the M11 cannot stream 352.8kHz content without connection loss (via Roon ARC), here the iPad is rock stable. So I guess for IEMs I will use the iPad und for over ears probably the M11 (without content above 192kHz).

 

[peterinvan]

My tests with Cayin RU6:

iPhone 6 (Lightning): will not work.
iPhone SE (Lightning): will not work.
iPad Air: (Lightning): will not work.
IPad Mini: (Lightning): will not work.

For my these devices I use the FiiO KA3. Its a step down in sound quality, but works well with Lightning output.

iPad Pro (USB-C): works great
FiO M11 Pro (Android, USB-C): works great

The RU6 drives all my phones (see below) at 30 - 35db

My guess is that you need a USB-C out to drive the RU6.

 

[peterinvan]

If the RU6 itself works, then the fact that the screen has peeled off is not a big problem, you can fix it at the service center where smartphones are repaired, they will glue this protective glass of the screen.

I had one side of the screen lift off. I applied 2 tiny drops of Super Glue under the edge of the glass, and taped it up while it set.
Good as new.

 

[Daiyama]

My tests with Cayin RU6:

iPhone 6 (Lightning): will not work.
iPhone SE (Lightning): will not work.
iPad Air: (Lightning): will not work.
IPad Mini: (Lightning): will not work.

For my these devices I use the FiiO KA3. Its a step down in sound quality, but works well with Lightning output.

iPad Pro (USB-C): works great
FiO M11 Pro (Android, USB-C): works great

The RU6 drives all my phones (see below) at 30 - 35db

My guess is that you need a USB-C out to drive the RU6.

Thanks,
yes it looks like an USB-C output is required for power hungry over ears.
However this is not my main use case, I will mainly stick to IEMs then I should be fine with all the device options I have here.

 

[Andykong]

Thanks, that is right a dongle out of a DAP seems a bit strange.
Do you happen to know if there are differences in USB output between different ipad types, as I have not an iPad pro, only an iPad 5th gen.

So my iPad 5th gen is not the optimal fit.
When using the RU6 with my HE1000V2 (ai know a bit of a stress test), at around 55 volume level, the RU6 is turned of, listening volume is very low. For inears it’s fine.
With the M11 I can go up to 98 (above 88 I had to take the headphone of), only at 99 and 100 a stutter starts. On the other hand the M11 cannot stream 352.8kHz content without connection loss (via Roon ARC), here the iPad is rock stable. So I guess for IEMs I will use the iPad und for over ears probably the M11 (without content above 192kHz).

I am an Android man, and I am not familiar with different versions of the iPad, I just happened to use iPad Pro in one of the show demos and I find it very good, on par with the best Android USB output I have experienced.

Having said that, I don't think RU6 with iPad Pro or an Android source can power the HE1000V2 properly. We never recommend RU6 for full-size headphones, let alone power-hungry full-size planar, so this is not relevant to the power limitation of iOS devices. I would say there is a slim chance that HE1000SE will work OK, but definitely not HE1000V2. This is, IMHO, a fairly unrealistic expectation of RU6.

 

[Andykong]

My tests with Cayin RU6:

iPhone 6 (Lightning): will not work.
iPhone SE (Lightning): will not work.
iPad Air: (Lightning): will not work.
IPad Mini: (Lightning): will not work.

For my these devices I use the FiiO KA3. Its a step down in sound quality, but works well with Lightning output.

iPad Pro (USB-C): works great
FiO M11 Pro (Android, USB-C): works great

The RU6 drives all my phones (see below) at 30 - 35db

My guess is that you need a USB-C out to drive the RU6.

When you said "will not work", I assume you can't get the RU6 to function correctly? No sound output at all?
Please be reminded that you need a Lighting to USB-C cable that can deliver 5V in order to use RU6 as USB DAC for your iPhone or iPad (HERE). Most charging/data Lighting to USB cabless are rated at 3.3V only, so they aren't fit the job.

 

[Daiyama]

Thanks Aady, that is a very good point. I use the apple camera connection kit. Maybe simultaniously charging change this? Maybe not, if the adapter is specified for 3.3V.
Do you know if using an Android USB audio out and charging using some kind of an adapter ist possible? I could not find a clear answer to that by googleing it.

As I said I only used the HE1000V2 as a "stress test" and will mainly use the RU6 with IEMs (and if overears way more efficient one than the HE1kV2). And it is also clear that this behaviour is not the fault of the RU6. It is the fault of the Apple devices.

 

[giuca70]

Thanks Andy for the kind replies.
In the end maybe I understood why the RU6 sounds better from a pc than from a smartphone or tablet, I'll try to explain it simply: I tested a difficult pairing, Monolith AMT and RU6 in balanced mode
1 - from smartphone with usb-c 3.1 to Cayin it plays with android 13 max volume and decent quality with 192 Khz upsampling, but it is not recommended
2 - from a tablet with usb-c 3.1 the volume is the max of android 12 and upsampling 384 KHz, the quality is much better (grain), but it is not recommended
3 - from PC I have the impression that the windows driver improves the dynamic volume blocking it at max towards RU6. It's different, it sounds good.
.
The union of the difficult (indeed impractical) load of the AMT with RU6 helps to sum up, being the AMT very revealing. All test in high gain.
For these tests I have chosen articulated passages, these:
.
Ibakan - Nu Deco Ensemble -
.
Black Gold -

 

[Surdzo]

Black Gold -

I appreciate your effort but in my opinion, weird choice of music for testing RU6.
I mean, Lucrezjq ORO NERO kind of music is for delta sigma dac testing not for R2R
RU6 in my opinion is for vocal centric slow type of music, instrumental music (non electronic) so Jazz, Blues, Soul, Pop, Country, Folk Americana…

 

[Andykong]

Thanks Aady, that is a very good point. I use the apple camera connection kit. Maybe simultaniously charging change this? Maybe not, if the adapter is specified for 3.3V.
Do you know if using an Android USB audio out and charging using some kind of an adapter ist possible? I could not find a clear answer to that by googleing it.

As I said I only used the HE1000V2 as a "stress test" and will mainly use the RU6 with IEMs (and if overears way more efficient one than the HE1kV2). And it is also clear that this behaviour is not the fault of the RU6. It is the fault of the Apple devices.

You might need to acquire a splitter/charger such as ddHiFi TC28i Pro lightning to USB-c OTG and power adapter. This adapter adds another USB-C power port specifically for charging (review HERE), hence allowing you to use Dongle DAC and charge your mobile phone at the same time. I believe ddHiFi offers a USB-C version of this adapter too.

 

[Daiyama]

Thanks!
For my quick reasearch the lightning version seems to be easier to get.
And with this adapter the RU6 should get the power from the chargeing device and not from the ipad so the drop outs will not happen anymore?
Or does the adapter "only" charges the iphone and the RU6 still gets the "limited" power from the iphone?

 

[ExTubeGamer]

I am warming my RU6 up till my jitterbug is gonna arrive in the next few days.

My system is not noisy but I still hope for an improvement. The treble is the only area in my setup that is not perfect. Just a little more clarity in the treble. That's all I need.

 

[oldkid]

I am warming my RU6 up till my jitterbug is gonna arrive in the next few days.

My system is not noisy but I still hope for an improvement. The treble is the only area in my setup that is not perfect. Just a little more clarity in the treble. That's all I need.

I feel more confident recommending the jitterbug add-on to my fellow RU6 enjoyers now that @Andykong has confirmed how sensitive Cayin's R2R DAC is to incoming data's integrity.
I couldn't explain how exactly, but the jitterbug does audibly reduce jitter.

What's even more exciting is the fact that RU7 has an on-board chip tasked with reclocking and de-jittering duties. On paper, RU7 is a dream device. It does everything I could have asked for.