While functionally N3Pro reminds me of N8 Jr, the exterior design has more resemblance with N6ii, especially around volume wheel and hardware playback control buttons. As expected, with a lot more built-in functionality, N3Pro will be bigger than its N3 brother-from-another-mother. Actually, its overall size of 115×63.5×18.9mm is closer to N5ii. With the weight of 195g it is lighter than N6ii and N8, but you still feel some heft when holding it in your hand. Its compact pocket friendly size and weight makes it very comfortable to hold and to operate in one hand and being able to easily reach across the touch screen with a thumb even if you have average or smaller size hand.
And speaking of touch screen, I assume it’s the same 3.2” IPS touch display with 480×360 resolution as used in N8. The whole top surface is glass, only 3.2” area is allocated for touch display. At the bottom, you have a round touch LED Home button which also has functionality to change LED color depending on sample rate of played file or when charging. The light could be disabled as well in Settings. The back of N3Pro seems to be glass as well, while the chassis frame is metal. There is nothing at the top, and the left side has a spring-loaded slot for micro SD card, the only internal storage option for N3Pro which you can expand up to 1TB with the latest high capacity flash cards, or you can add OTG external storage as long as it doesn’t draw more than 300mA of current.
As already mentioned, the right side resembles the design of N6ii. You will find a volume wheel at the top, surrounded by top/bottom guards. The wheel also doubles as a power button you long press to turn the power on/off and short press to turn the display on/off. Similar to N6ii, the wheel is not super tight, allowing easy control with just a thumb when you roll it up/down to change the volume. There is a click action as you turn it with every step. Below the volume/power wheel you will find 3 playback control buttons, comfortably spaced even for fat sausage fingers, where you have Play/Pause in the middle and Skip/Forward at the top and bottom. While chassis of N3Pro are all black, the volume wheel and buttons are golden, but it has a muted golden tone, not too much bling-bling in your face.
All the ports are located at the bottom of N3Pro. Multi-function USB-C port supports charging, file management, USB DAC, digital Transport, as well as embedded SPDIF Out using optional cable to bring out Coax output. Then, you have a dedicated 3.5mm SE Line Out with a selectable output voltage of 2.0/1.5/1.0V corresponding to High/Mid/Low in Settings. Next to it is SE 3.5mm Phone output which you select as either SS or Tube in Settings and change the gain between H/M/L. Tubes output is only from 3.5mm jack. And last, but not least, 4.4mm BAL output which is shared between Phone output (SS only, H/M/L gain) or BAL Line Out with also has a selectable voltage level of 4.0/3.0/2.0V corresponding to High/Mid/ow in Settings.
Under the hood.
In the heart of N3Pro you have a dual AKM Velvet Sound AK4493EQ DAC, with a playback support of all the popular lossy and lossless audio file formats, including PCM decoded up to 32bit/384kHz, handling DSD up to DSD256 and even SACD-ISO. I went back and forth switching between mp3, flac, and DSD (DSD64, DSD128, and DSD256) files, and didn’t experience any noticeable lag in the audio playback. Since no internal storage is offered, you will have to use micro-SD cards, though those are growing in storage capacity and dropping in price. Plus, you can connect additional storage via USB OTG, just make sure it doesn’t draw more than 300mA of current.
As previously mentioned, the display is similar to N8, 3.2″ IPS with resolution of 480×360, nothing special by today’s smartphone standard, but considering it’s not intended for apps or video playback, this is more than adequate. Plus, I’m not too picky about the quality of embedded artwork. Also, the viewing angle was good, thanks to IPS display, and the same with visibility in a daylight, just need to bump the brightness setting higher. Considering compact size, the battery capacity of 4100mAh (3.7V) is not bad, and you will get up to 11hrs of playback time from 3.5mm SE SS output, or up to 9hrs of playback time from either 4.4mm BAL SS or 3.5mm Tubes outputs.
The headphone output spec can shed some light about the design since 4.4mm BAL (1ohm impedance) can drive up to 800mW into 32ohm load, while 3.5mm SE (0.6ohm impedance) scales it down to 250mW @32ohm (SS) or 130mW @32ohm (Tubes). Obviously, if you need extra power to drive your more demanding headphones, SS Balanced output would be the way to go, while SS/Tubes Single Ended are for easier to drive headphones and IEMs. I will cover various IEMs/headphones examples in Pair up section of the review.
You also have WiFi support (2.4GHz band only, according to Cayin spec), so you can upload fw OTA or do wireless music file transfer. Though only a single band, in reality this is not Android DAP intended for streaming or running apps, thus single band WiFi is not a showstopper. Instead, Bluetooth plays more important role here, and BT 5.0 with a duplex operation (Rx/Tx) has a higher value. From the Bluetooth menu under Quality option I see an option for LDAC, UAT, aptX, and SBC, and while AAC is not listed, several users on Head-fi reported about being able to stream AAC from their iPhone. With a duplex BT, you don’t just pair up with wireless headphones/speakers, but also can pair up with your Smartphone to use N3Pro as a hi-res Wireless DAC/amp.
Of course, I saved the best for last. What makes N3Pro stand out from other DAPs in a similar price range is dual Timbre design of using either Solid State or Tubes. Cayin doesn’t call it SS and Tubes amplifier design because the selection between SS and Tubes is an audio buffer before going into the final Phone Amplifier stage. Thus, Cayin refers to this part of the circuit as SS Timbre and Tubes Timbre, user selectable from 3.5mm port (SS or Tube) or SS only from 4.4mm port.
The tubes used in the design are Raytheon JAN6418, vintage miniature pentode tubes, known for their low power consumption which is appropriate for a portable use. These are not considered to be very warm tubes, but have just enough to give the sound a warmth and texture which is different from Solid State timbre signal path. Also, only two matched Tubes are used to cover SE output because fully balanced design would require not only 4 matched Tubes but also doubling of the ckt around it. The compact footprint of N3Pro wouldn’t be able to fit all the ckt to a have a fully balanced Tubes output.
Cayin printed circuit board (front/back):
Just like with any real Tube, you also have to deal with microphonics effect due to vibration of the filament. For that, Cayin designed a custom silicone case, suspended inside N3Pro with a flexible PCB. This way you can move around without too much of microphonic effect, but you have to keep in mind when you tap or shake the DAP, you will hear some ringing which goes away after a few seconds when you hold it steady. Also, by default, when you switch from SS to Tubes or pause for a few minutes, you have to wait 5sec for Tubes to warm up and stabilize after being powered up. And even after this 5sec timeout, sometimes it could take another 5-10sec to fully stabilize the output sound.
Tubes by itself are not the only highlight of this design. When you switch from SS to Tubes timbre, you also have a choice of 2 Tubes modes: Triode and Ultralinear to give you more variety in fine-tuning and coloring of your sound, as part of their DOM (Dual Operation Mode which first appeared in HA-6A desktop tube amplifier). I will go over the details between SS and Tubes and Triode (TR) and Ultralinear (UL) in Sound Analysis section of the review, but as a spoiler – the difference between TR and UL is quite noticeable. So, overall, you are getting a DAP with 3 different sound timbres, Solid State, Tubes Triode, and Tubes Ultralinear.