After almost one week and +50 hours of listening to the Cayin RU6 I’m ready to share my more detailed opinion.
Cutting to the chase, I’m now actively searching for a Cayin n6ii with R01 (or other R2R dap) and a good R2R dac for my home audio system. Guess that says something of my opinion of the Cayin RU6…
Disclaimer
As always my ears are my ears, and my impressions are my subjective impressions. I honestly find it hard to put words in ”how something sounds” and the music library and timbre preference also plays a major role in perception of a device. I’m not a true believer in “audiosciencereview”, resolution >130 dB and SNR >120 dB etc., as music ultimately is all about the feeling and enjoyment created by the music.
General observations
- Pairing with different IEMs is of course affecting the overall perception of upstream equipment
- My assessment here has been done using the UM MEST MkII with 3.5 mm cable
- My ESS dac/amp dongles are in general a bit more detailed and analytical than the RU6
- My ESS dac/amp dongles are in general more prone to sibilance and fatigue after longer listening sessions
- For my ESS dac/amp dongles the amp implementation is coloring the sound into warmer or colder timbre (i.e. more or less shrill sounding)
- For normal listening the “brain burn-in” makes it hard to judge diminutive differences in timbre and sound quality
- I see no real life need for MQA (apologies to any still existing audiophile fan of MQA)
- I see no real life need for higher bit resolution than 24 bits (I’m more than 50 years old and my hearing is what it is in the upper trebles)
- I prefer device volume controls over UAPP (or other player) volume controls
- On an R2R dac NOS is the only filter mode I would consider as these devices are bought for their “analog sounding” characteristics
- 4.4 mm balanced is always better than 3.5 mm single ended, but again for this assessment 3.5 mm single ended was used for a like for like comparison
- On the RU6 and for this comparison I prefer the high gain setting when using the 3.5 single ended output as I perceive this to render in better dynamics (no need for the raw power on IEMs or <60 Ohm headphones)
- The RU6 is a wonderful device with a warm and cosy timbre while maintaining sufficient detail perfect for longer non-fatiguing listening sessions in a home or office environment
- I need to buy a good R2R dap as a complement to my phone and dongle setups (my eyes are currently on the Cayin n6ii Ti)
- I need to buy a good R2R dac for my larger and very stationary home audio system (my eyes are currently on the Musician Pegasus)
Comparisons
iBasso DC05 - RU6 has a warmer timbre, not as analytical but without lacking anything in terms of details and perceived resolution. I find the DC05 to have a tad better and a tad more airy treble representation bordering to sibilance, and the RU6 has far better bass/mid bass representation with full weight and warmth. For mids and vocals I find the RU6 very natural whereas the DC05 is more forward. Overall I prefer the RU6 for longer sessions due to the warm, cosy feeling that it provides.
I would recommend the RU6 for a larger spectrum of IEMs with different timbres, whereas I would not recommend the DC05 for bright IEMs unless you are a true treble-head. Furthermore the RU6 is less sensitive to imperfect recordings. For music on the go with “darker“ IEMs the DC05 is good and inexpensive option.
THX Onyx - More similar in initial timbre. I find the RU6 a bit more warm and natural sounding, and a tad less analytical. On timbre the Onyx is a bit more mid/treble forward and shines over the RU6 when doing analytical listening sessions with e.g. electrical guitar plucking, good female vocalists and electric pop with good mixing. I find the Onyx to have a bit faster bass response and slightly better punch, but for longer listening sessions I get fatigued by the more emphasized mids/treble on the Onyx.
I would recommend both the RU6 and Onyx for a larger spectrum of IEMs with different timbres, whereas I would not recommend the the RU6 for music on the go where the Onyx is a better choice given more power (single ended) and better portability. Furthermore the RU6 is less sensitive to imperfect recordings than the Onyx.
Audioquest Cobalt - RU6 every day of the year. I don’t even like the Cobalt for some reason.
NextDrive Spectra X - RU6 every day of the year. The Spectra X was good when it was released, but time flies and today i find it a bit harsh sounding.