John Darko
Cayin’s German distributor has this week announced the RU9, a portable DAC and headphone amplifier designed for smartphones, tablets and laptops. Inputs number two: USB-C (UAC 1.0/2.0) and LDAC/aptXHD Bluetooth. Outputs also number two: 3.5mm and balanced 4.4mm, where a switchable ‘DC mode’ (read: external power) promises up to 1 Watt into 32 Ohms. In between, a DAC circuit built around a pair of AKM4493SEQ laid out in a dual mono configuration handles the D/A conversion.
Now comes the wrinkle: the amplifier section is loaded with a Gen 5 6P1 Nutube that permits three user-selectable operational modes — the NFB-off “Classic”, the NFB-on “Modern” and the (tube off / op-amp only) “Solid State”. Volume control is handled by a knurled wheel inset into the RU9’s body with a nearby display showing volume level, incoming sample rate, headphone connection type and battery level. The RU9 sucks not on the host device’s battery but its own 2000 mAh lithium bank that Cayin rates as good for 4.7 hours between charges. So, just over half the Chord Mojo 2‘s runtime.
How to attach the RU9 to a smartphone? Cayin knows that rubber bands block access to the screen, so the rear of the unit’s CNC-milled aluminium housing has been magnetised. The RU9 weighs 150 grams but Cayin’s strapline, “the new age of dongle”, looks a little optimistic when we see its size: 100 × 70 × 15mm. A leather case is included in the box.
The supplied press shots show a USB-C-to-USB-C cable with right-angled plugs, presumably for easier pocketability. With the headphone sockets sitting nearby, let’s hope your headphones have the same.
Price? €598 or US$499.
Further information: Cayin
