DAPs just went down the tube with Cayin's N3Pro

A tube music player. The concept of Cayin Audio’s new N3Pro virtually sold itself before anyone had heard it. A short listen quickly convinced those a little behind of its worth. Everyone knew why they were buying it: the N3 Pro’s dual Raytheon JAN6418 segment. Not everyone knew what the tubes did.

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The expectations of tubes fueled the listening; the listening in turn put paid to the expectations. Warm sound? Not on Cayin’s little N3Pro. While sounding strongly non-digital, with a smooth sense of detail portrayed in a soundstage that bloomed far and wide beyond the confines of earphones and headphones, this little tube proved very adept at passing high frequencies. 

A close-up of N3 Pro's tubes

Tubes. You’ve known about them because of the amplifiers that were built using tubes. Which have led to certain presumptions about them.

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As output devices fronted by transformers, tubes passed the impression that they were warm, sluggish, muffled and slow in the bass. Not the sound of the tubes, though, but of the amp. Particularly old designs.

When used correctly as an input device, tubes give the N3Pro its biggest advantage over competition. Within and beyond its price bracket. Two conducting plates suspended in a vacuum, this player's tubes, like all their brethren sport vanishingly low input capacitance. The transmission path of small signals from dual AKM AK4493 chips to your earphones couldn’t be more pristine. 


The biggest challenge to implement JAN6418s in a DAP was handling the microphonic and shock treatment. We tried four different shock absorption silicon housings and six rounds of flexible PCB design, conducting lots of tests. The R&D difficulties are disproportionate to the entry-level position of N3Pro.

READ ALSO The design story of Cayin's N3Pro

Technology has moved on but the irony is that solid-state is still taking a leaf from the tube book. FETs (Field-Effect Transistors) are modern devices cherished for being, if even slightly, tube-like in layout and sound. But a V-FET and a MOS-FET can only mimic a real-to-life triode and pentode tube’s characteristics this much. 

This is after-the-fact reasoning: it’s always been clear the N3Pro's tubes are the source this Cayin’s budget entry’s effortless portrayal. If N3Pro’s sound quality infinitely scales and headroom seems unlimited, that’s also due to its tubes requiring high operating voltages: a mighty 22.5 volts. A paltry +/- 5V on solid-state counterparts seems so yesterday.


In Triode Mode, the presentation and soundstage will sound more sophisticated and elegant. When changed to Ultra-Linear Mode, transients will be enhanced and soundstage will open up. You can feel space and dimension immediately, and the music becomes lively, clean and energetic.

BUY NOW Cayin N3Pro

A trick learnt by tube gear manufacturers of yesteryear was that high voltage equals high linearity. Striving to have the output of an amplifier equal the signal at the input, linearity was prized. Entirely suitable for use in a portable function, draining little battery, generating less heat and ensuring a long-life span, the JAN6418's give the N3Pro an edge at any price.

A high operating voltage was the simple solution, tubes an easy application. When the greater part of the audio band output is linear, other nasties don’t have to be resorted to. 

Goodbye excessive use of negative feedback, goodbye harsh-sounding intermodulation distortion (IMD) and goodbye transient intermodulation (TIM). Elements that had been used to cure problems in solid-state needn't be used here, because the problems don't exist to the extent on tubes. 

'Problematic' tubes turned out to be quite the solution. Without the design budget to dot the i's and cross the t's in an extensive solid-state circuit, Cayin's N3Pro doesn't break the audiophile's bank for superior sound quality. Implemented before a proper power stage, tubes as input voltage devices in personal audio are anything but obsolete – only our thinking about them.