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

[c1pseudonaz]

Will it be available in shops soon after announcement ?

 

[tjzurlaaa]

While we are busy working on our new high-end products, we have also devoted a lot of resources to passing down our new technologies to more affordable applications.

Cayin will conduct a new Dongle DAC live stream on 18 May 2023, 7:30 pm (UTC+8). As usual, We shall post product details with specifications, prices, and launch dates after the live streaming, so please stay tuned.

If you are attending Munich High End Show 2023, please check out Cayin booth at Halle 1 D16, on top of hand-on out the newly announced RU7 Dongle DAC, you can also check out our full range of Personal Audio products including N7 1 Bit DAC DAP, N8ii Flagship DAP, C9 and also our Tube Headphone Amplifiers HA-300MK2, HA-6A, HA-3A.

I am so interested in this I really hope they worked out all of the kinks with the Ru6 I would totally buy in a heartbeat

 

[BlueA]

Ok I was expecting more resistors and I get 1-bit.
Blind buy!

 

[Auricon]

Also 1bit need high audio format, not sure that dongle that aim for phone and portable are the best devices to provide required huge storage.

Cayin debuted their discrete fully-balanced 1-Bit Resistor Network “DSD” DAC in the N7. The FPGA to Audio Bridge de-jitters and transcodes/oversamples PCM (16-32bit / 44.1k~768kHz) to DSD64/128/256/512 to DAC:

https://www.head-fi.org/threads/cayin-n7-a-voyager-of-unexplored-frontier.966860/

 

[BlankName]

If it’s dac design is anything like the N7, it’ll be a beefy dongle.

 

[BlueA]

Cayin debuted their discrete fully-balanced 1-Bit Resistor Network “DSD” DAC in the N7. The FPGA to Audio Bridge de-jitters and transcodes/oversamples PCM (16-32bit / 44.1k~768kHz) to DSD64/128/256/512 to DAC:

Like @BlankName said too, to feed this we gonna have first a large format but we're gonna need a lot of space on the phone or any portable device to store required file format. Easy for Android device to add a SD no so for apple device. I'm expecting something around 800$.

 

[povidlo]

drooling.

 

[Auricon]

Like @BlankName said too, to feed this we gonna have first a large format but we're gonna need a lot of space on the phone or any portable device to store required file format. Easy for Android device to add a SD no so for apple device. I'm expecting something around 800$.

It transcodes/oversamples locally or streaming, you don't need a large file format (some of my smallest files are 10mb 44.1khz / 320kbps MP3s) or use local storage on your device to take advantage of its capabilities.

 

[BlueA]

It transcodes/oversamples locally or streaming, you don't need a large file format or use storage on your device to take advantage of its capabilities.

To my knowledge the technology first emerged in high volume compact disk to provide the required level of details.
I did not know about upscaling feature yet it will loose detail if the source is not top notch.
So between storage and battery consumption is it really gonna target phone like RU6 is ?

Hum maybe like Shanling H7 it will be able to accept SD on board so Iphone user can benefits too from large storage.

 

[povidlo]

Cayin debuted their discrete fully-balanced 1-Bit Resistor Network “DSD” DAC in the N7. The FPGA to Audio Bridge de-jitters and transcodes/oversamples PCM (16-32bit / 44.1k~768kHz) to DSD64/128/256/512 to DAC:

https://www.head-fi.org/threads/cayin-n7-a-voyager-of-unexplored-frontier.966860/

Is this similar to sony's dsd remastering, but sony does it on software level while cayin is doing upsampling through hardware?

 

[Auricon]

Is this similar to sony's dsd remastering, but sony does it on software level while cayin is doing upsampling through hardware?

Yus, through the Audio Bridge.

https://www.head-fi.org/threads/cayin-n7-a-voyager-of-unexplored-frontier.966860/post-17422765

Discrete Resistor Networks for DSD Format

While reviewers and users appreciate 1-bit DAC technologies as natural, smooth, and realistic when compare to their analog experience in the practical world, they are inevitably not as popular as their PCM counterparts. The not-so-impressive measurements have hesitated a lot of vendors to devote their resources to 1-bit DAC. In addition, the existing solutions are far too bulky and consumed too much power for personal audio, so we didn’t have any 1-Bit DSD DAC implementation for DAP or even transportable DAC/Amp. To introduce 1-Bit DAC to our portable users, Cayin designs a micro-miniaturized 1-bit DAC circuit from fully discrete components:

1. DSP Pre-processing: Enhance digital audio signal and output L+, L-, R+, and R- digital bitstream for fully balanced decoding.
2. Audio Bridge: pass-through DSD unaltered, convert PCM to 1-bit bitstream before transmits to DAC circuit
3. Discrete 1-Bit DAC: convert digital signal to analog signal through a resistor network composed of 128 pcs (4 x32) high precision Thin Film Resistors
4. Power Supply: Sophisticated low-noise highly-isolated supply circuit to support different functions of digital and analog processing separately

As mentioned previously, 1-bit DAC is very sensitive to the integrity of the incoming digital signals, we have to perform a series of DSP pre-processing including re-clock, de-jitter, and noise shaping. The resulting bit-stream will then be passed to Audio Bridge where all incoming signals will be organized before feeding to the DAC circuit. If the incoming signal is DSD, then it will be pass-through without any conversion. If the incoming signal is PCM, it will be transcoded and upsampled to DSD512. Theoretically, FPGA is a good fit for this job, but the FPGA we adopted for N7 cannot handle (1) and (2) simultaneously, we need to off-load either (1) or (2) to other options, and after numerous studies and experiments, we decided to add a single chip SRC (Sample Rate Converter). With this design, DSD playback will remain purely software-based DSP in (1) and (2), while PCM playback will go through the single chip SRC plus software DSP in FPGA/MCU

The Serial to Parallel Shift Registers will convert the serial data signal to a parallel data signal and transmit it to the DAC circuit. In our test, FPGA can carry out the Shift Registers functions beautifully but in view of the loading of our FPGA, we opted for a hardware solution here. The 1-bit DAC circuit is fully differential by design. Each channel is composed of 32 pieces of high precision low TCR Thin Film Resistors rated at ±0.1% (or ±0.001 or ±1/1,000). The temperature coefficient of resistance (TCR) of these resistors is also respectable. It is rated at TCR25 (±25 ppm/℃), and the resistor value will only fluctuate within 25/1,000,000 per 1-degree change in temperature. By fully differential, we need 4 rails of resistors to decode L+, L-, R+, and R- channels separately, hence 128 pieces in total.

 

[CT007]

Will RU6 owners get a discount?

 

[rmkjr]

What is the difference between a "1-bit DAC" implementation like the N7 and a normal delta-sigma DAC chip? Is this sort of implementation is just a discrete or more complicated and expensive implementation of a delta-sigma chip based DAC?
https://en.wikipedia.org/wiki/1-bit_DAC

I.E. R2R and sigma-delta are different designs, but a "1-bit DAC" is actually how a sigma-delta chip works and this one instead of being a integrated chip uses an FPGA for oversampling, followed by a set of "discrete" components, and a "discrete" LPF? If so, it seems a little bit "market-y" to me...

This kind of follows, at least in my head, as I have heard others say in the past that delta-sigma DACs are all DSD internally.

 

[Casey’sToneQuest]

OooOooOo can’t wait to see what the RU-7 is all about!

 

[BlankName]

Is this sort of implementation is just a discrete or more complicated and expensive implementation of a delta-sigma chip based DAC?

Pretty much, it removes size and cost, to some extent, restraint.