Cayin RU6: R-2R USB Dongle DAC with Head-Amp

[Andykong]

No.
He Andy did not say any thing close to your expressed.
He said Ru6 adjust volume output at analog stage. It means resistor to adjust volume will not do the "dac" function.
I can put an example. When you click + once, a resistor join the audio path.
To not requires upto 100 resistors, they are in array/matrix.
Those array, imo, lay somewhere between amplifier chip and R2R matrix (this matrix do digital-analog conversion) and doesn't need high accuracy.
Guess that you want vol 70 is 66dB but by inaccurate value, become 66.6dB is not ideal but affect nothing!!
R2R matrix do need high accuracy. Analog signal get from them is somewhat 0~2V (0.0006V each step theoretical) so if those resistor error 1% the output is not presice for music.

In short: R2R matrix works natively and independent from physiscal button on Ru6. It's resitor is not the one which use for volume adjustment

Thank you for clearing the doubt. For the record, there are two sets of resistor networks in RU6, One set is the 24Bit Discrete R-2R Resistor Ladder DAC that composed of 96 pieces of high precision low TCR Thin Film Resistors rated at ±0.1% (or 1/1,000) and TCR25 (±25 ppm/℃), the second one is the Resistor Array Volume Control. The cost and complexity of building the discrete DAC and discrete Volume control far exceed the cost of buying those off-the-shelf highly integrated multi-function "programmable" DAC chipsets. We understand a lot of users are so used to the convenience and flexibility of the highly integrated DAC solutions, that discrete DAC approaches such as RU6/RU7 become a very niche market and they are not necessarily good for everyone. We got that, that's why we tried our best to explain the constraints and limitations of our product on the first page of this thread and on the RU6 product page of the Cayin website. We try to steer users away as early as possible if this is not the right product for them.

 

[oldkid]

Thank you for clearing the doubt. For the record, there are two sets of resistor networks in RU6, One set is the 24Bit Discrete R-2R Resistor Ladder DAC that composed of 96 pieces of high precision low TCR Thin Film Resistors rated at ±0.1% (or 1/1,000) and TCR25 (±25 ppm/℃), the second one is the Resistor Array Volume Control. The cost and complexity of building the discrete DAC and discrete Volume control far exceed the cost of buying those off-the-shelf highly integrated multi-function "programmable" DAC chipsets. We understand a lot of users are so used to the convenience and flexibility of the highly integrated DAC solutions, that discrete DAC approaches such as RU6/RU7 become a very niche market and they are not necessarily good for everyone. We got that, that's why we tried our best to explain the constraints and limitations of our product on the first page of this thread and on the RU6 product page of the Cayin website. We try to steer users away as early as possible if this is not the right product for them.

Both RU6 and RU7 are tremendous engineering achievements in my opinion.

The only reason why I don't use RU6 as often as I used to is the EMI noise problem when it is used with a mobile phone.

I still daily drive my RU7 on my commute in one of those crazy setups inspired by people of this forum, where the DAC is powered by an external battery. I also used it exclusively in line out mode with a tiny portable amp, mostly to have a volume knob and with active noise cancelling IEMs. This allows me to enjoy desktop quality sound on the go and it is only possible thanks to Cayin efforts to constantly innovate in a market full of clones.

Thank you very much @Andykong and everyone else at Cayin for this line of affordable yet awesome products.

 

[ACF8972]

For anyone using the RU6 as part of a desktop setup:

1. What gain/volume setting is it set at?
2. Does it have any issues with staying connected for extended periods? (e.g. excessive heat, connection dropouts)

Would be double amping through an iFi Zen Can. Thanks in advance to anyone willing to answer!

 

[Andykong]

For anyone using the RU6 as part of a desktop setup:

1. What gain/volume setting is it set at?
2. Does it have any issues with staying connected for extended periods? (e.g. excessive heat, connection dropouts)

Would be double amping through an iFi Zen Can. Thanks in advance to anyone willing to answer!

I suggested a double amping setting (HERE), but this is for reference only. If you want to read the whole story, you can go through all the links HERE, this should clarify the design considerations and limitations of RU6 when you want to use it as a DAC for another amplifier. In other words, RU6 is not designed for this purpose, you can do that if you insist and it is technically safe, but it does not function at its best. RU7 has a shared line-out feature that might work better IMHO

 

[Huxley]

Anyone know of a good shielded usb c cable that'll work with this, I bought me a lovely inntak from AliExpress but it won't power it on, I'm guessing it didn't supply the 5v required

 

[davide256]

this looks desirable, designed for player to portable DAC use
https://www.ddhifi.com/en/product/tc05-m2-usb-c-to-usb-c-otg-cable/

 

[MacMan31]

I suggested a double amping setting (HERE), but this is for reference only. If you want to read the whole story, you can go through all the links HERE, this should clarify the design considerations and limitations of RU6 when you want to use it as a DAC for another amplifier. In other words, RU6 is not designed for this purpose, you can do that if you insist and it is technically safe, but it does not function at its best. RU7 has a shared line-out feature that might work better IMHO

I was just wondering about this as I just picked up an RU-6 used. Sound is excellent with my Focal Hadenys. However I was wanting to use it with another amp to gain more power. Perhaps an RU-7 would be a good choice to pick up. Do you know if the line out on the RU-7 is only through the 3.5mm or also through the 4.4mm output?

 

[Brain Damage]

I was just wondering about this as I just picked up an RU-6 used. Sound is excellent with my Focal Hadenys. However I was wanting to use it with another amp to gain more power. Perhaps an RU-7 would be a good choice to pick up. Do you know if the line out on the RU-7 is only through the 3.5mm or also through the 4.4mm output?

It can function as a LO through both 3.5mm and 4.4mm.

I would only use 4.4 LO if you have a balanced external amp to keep the balanced chain throughout; otherwise use LO through 3.5 - especially for sensitive, low impedance (dynamic drivers) IEMs and cans.

 

[PopZeus]

RU6 is a great device for IEMs but I’ve never been happy using it as a DAC only. The RU7 or an R2R DAC with a dedicated line out mode would be better.

 

[TYATYA]

RU6 is a great device for IEMs but I’ve never been happy using it as a DAC only. The RU7 or an R2R DAC with a dedicated line out mode would be better.

Is that correct Ru7 has true line out?
I dont think so. It is the same the way A&K implement, just fix volume (optional, 0.7-1.4-2.25...etc) not true lineout that obtain signal out of the dac.

 

[senorx12562]

Is that correct Ru7 has true line out?
I dont think so. It is the same the way A&K implement, just fix volume (optional, 0.7-1.4-2.25...etc) not true lineout that obtain signal out of the dac.

As I recall, Cayin claimed it was a true line-out at the time, and the output voltage isn't variable. But both se and bal are lower than the standard 2v and 4v.

 

[Andykong]

As I recall, Cayin claimed it was a true line-out at the time, and the output voltage isn't variable. But both se and bal are lower than the standard 2v and 4v.

In short, RU7 line out is a convenience feature, it didn't bypass the headphone amplifier, and is inferior compared to line out of N7. I have written a short paragraph to explain the line-out implementation of RU7, please go to the opening post in the RU7 thread and scroll down to the "Shard 3.5mm and 4.4mm Line Out" paragraph, hopefully, that should provide a good understanding of the line-out implementation of RU7.

We have also explained that the RU7 offered a shared line out that is a fixed voltage output from the Phone Out of RU7 on the official product page on the Cayin website.

 

[PopZeus]

Is that correct Ru7 has true line out?
I dont think so. It is the same the way A&K implement, just fix volume (optional, 0.7-1.4-2.25...etc) not true lineout that obtain signal out of the dac.

I never said it was, since it’s not a R2R DAC. It’s just that it was a better option than the RU6 for a line out function. The R2R DAC I was thinking about was the K11, which has a dedicated line out stage.

 

[Hyde00]

I never said it was, since it’s not a R2R DAC. It’s just that it was a better option than the RU6 for a line out function. The R2R DAC I was thinking about was the K11, which has a dedicated line out stage.

But yeah as far as I know:

RU6 = no line out
RU7 = has line out
K11 R2R = has line out
Shanling EH2 = a new dac/amp combo that's coming out that's also R2R and has line out

https://www.head-fi.org/threads/int...-3w-32Ω-headphone-amplifier-at-369usd.975059/

We're slowly getting more and more budget R2R devices.

 

[senorx12562]

In short, RU7 line out is a convenience feature, it didn't bypass the headphone amplifier, and is inferior compared to line out of N7. I have written a short paragraph to explain the line-out implementation of RU7, please go to the opening post in the RU7 thread and scroll down to the "Shard 3.5mm and 4.4mm Line Out" paragraph, hopefully, that should provide a good understanding of the line-out implementation of RU7.

We have also explained that the RU7 offered a shared line out that is a fixed voltage output from the Phone Out of RU7 on the official product page on the Cayin website.

Thank you for correcting my error Andy.