Cayin RU6 USB DAC Headphone Amplifier

Product Information

This deactivates the digital filters and the signal is retained in perfect timing. That is, the phase distortion and jitter remain at a very low level with no artifacts in the output signal. The RU-6 also pairs very well with the Burson Soloist 3X and the TEAC HA-501 enhancing the natural replay of the first and the musicality of the second and paired with these two gives me same but also a bit different enjoyment vs the Mytek Liberty DAC. The following comparisons were completed using a Samsung S23 Ultra and an Apple iPhone 13 Mini as our main transports. For IEMs and headphones, we used the Noble Audio Ronin, the 64 Audio Trio, and the Meze Audio Elite headphones. Cayin RU6 The M15 is a curious mix, an outlier if you will with only its sibling the M12 coming in any way close to its uniqueness. This is a combination of a tried and tested delta-sigma DAC with Questyle’s own current mode amplification.

The OLED screen will display sampling rate, volume level, gain H/L and whether you are using NOS or OS mode. The Analogue Discrete R2R tonality is something I have grown very fond of. The Cayin Ru6 delivers the R2R performance within a very portable size and the tonality is comparable to any R2R DAP. It has the warmth of any R2R typical tuning and can no way be considered bright. The basic idea of R-2R ladder is a matched pair of two resistors, the first is “R” and the other is “2R”which has twice the value of R. To achieve 24bit decoding, we need 48 pieces of resistors (23 x R and 25 x 2R), and that’s good for one channel. So for a stereo 24Bit R-2R decoder, we need exactly 96 pieces of resistors. The digital audio section of the R01 Audio Motherboard DAC circuitry can be divided into four subsystems:USB Audio Bridge: receive different audio format from USB, go through high precision signal enhancement, and output I2S bit-stream for subsequent processing. Still, if you want more vocal and instrumental richness in your timbre then the RU7 is the better option. Combined with the improved separation and larger soundstage it is a step up for me over the M15 with the like of the Ronin. R-2R DAC circuit is very demanding on incoming data integrity, the digital volume Despite being Analogue, RU6 exhibited exceeding competency with technicalities. Tested with my listening gears, what I am hearing is super transparent resolution throughout the dynamic range. Being Analogue sounding does not mean it has to be fuzzy. Details articulation is crisp and convincing, so is the resolution of imaging. The more resolving the pairing partner the better it is. In fact when paired with my ER4SR and Shure KSE1500 I am hearing every micro details that are available in the recordings.

Nonetheless, with all my music the RU6 was punchy, full sounding with great macro dynamics from electronic music to classical. Tonality is very cohesive from top to bottom and there is great consistency of note intensity throughout the whole frequency range where the KA3 tends to lose some of its weight while reaching the higher frequencies. The Cayin RU6 was the company’s debut dongle as well as the first-ever dongle to be launched using R-2R technology. It was also our Top Gear 2021 Award winner. You can read our full review of the RU6 here from the same year. Technical Dongles are getting more and more popular and there must be dozens of brands right now with a USB Dongle in their product line-up. It’s almost impossible to follow up on all of them, but in all honesty, I don’t think that’s needed either. There are some really good and affordable USB dongles out there from the bigger brands and looking at those probably gives you a 90% on the market and possibilities. Think AudioQuest, Fiio, Cayin, EarMen, xDuoo, etc. Dongle wars, it’s (not?) for everyone.There’s nothing ‘digital’ about the sound – it does indeed sound analogue. But what’s so outstanding about it is you’re not giving up any fidelity for the natural tone. It doesn’t compromise on technicalities to give you that silky smooth presentation.

I compared all four dongles against each other and, for common frames of reference, my Sony ZX2 DAP and my Lotoo Paw S1.Sound-wise the RU6 is an absolutely stellar performer and more than highly recommended especially if you are already a fan of the R-2R technology and you would like to experience it from a portable device or if you seek to discover the R-2R sound without breaking the bank. The FC6 does have an edge in decoding capability with an excellent DSD512 and PCM 32BIT/768kHz capability as well as MQA 8X unfolding. The RU7 is capped at DSD256 and PCM 32BIT/384kHz and has no MQA unfolding capability albeit there is some debate on how useful that will be in the long term. Mids and vocals are naturally warm, naturalistic and have very good details. They are a little bit forward but in a very good way that doesn't overpower the bass and treble. These are mids that give you the entry level to R2R signature - do not expect Ares II performance but the level produced is far different and higher in naturalism than leading MQA dongles. The onboard DAC inside the M15 is a fairly popular one called the ES9281AC PRO which is a chipset from ESS launched in 2021 and used by various manufacturers and the one you will also find inside the smaller M12. I will be editing, but this is what I have thus far... sorry for the literal cut-and-paste from my "edit" space.

The additional balanced output power, the technical capability, and several All-To-DSD modes are just some of the key features that elevate and differentiate the RU7 from its peers and the competition. Cayin RU7 Technical SpecificationsThe RU6 is the first portable USB DAC/Amp from Cayin. We have noticed the enormous demand in the Dongle DAC market, but we are not satisfied with the highly integrated off-the-shelf solutions, so we take our time to look for the right technologies. By the time we completed R01 Audio Motherboard R&D for N6ii DAP, we noticed the R-2R resistor ladder network can be implemented as low power consumption DAC circuit that offers outstanding audio performance. The bigger difficulties are space and operation limitations but we are confident that R-2R Dongle DAC is technically feasible. The RU6 is plug'n play compatible with all USB-OTG devices (iOS and Android), Mac OS, Windows PC through the available driver and it can also be connected to Digital audio players that support USB out. The most notable difference I hear between these two devices is in the treble. The Sparrow’s high frequencies occasionally exhibit some ringing (more akin to RU6’s OS mode). Other than that, Sparrow has a lower noise floor and a cleaner overall presentation.