HiBy R4

For an entry-level player, working with high open-loop performance before feedback is applied is no mean feat ... not to mention being able to handle considerable current and provide actual power into low-impedance IEMs.

Distortion always remains low when you're listening, helped by its amplifier's Class A operation. 16 output transistors are fully biased to achieve their most linear open-loop operation, ensuring an accurate reproduction of your music without the excessive use of negative feedback. 

This means that the increasingly low impedances of modern IEMs will be dealt with adequately. R4's output devices are truly capable of handling current and outputting up to 525 milliwatts of power – it's not a player that will lose composure dealing with loads from Empire Ears and Vision Ears.

Picking this HiBy up quickly on the go does not mean sacrificing fidelity. Using op-amps would have been too easy, and HiBy firmly stick by their discrete amplification guns even at R4's price of entry. It's a level of detail that's paid off in natural, accurate sound, reproducing the detail its quad of ESS ES9018C2M DACs are capable of.

The attention paid to R4's digital decode extends beyond its DACs, its FPGA and dual crystal oscillators – it's in HiBy's desire to split its quad array of chips into two pairs. One pair decodes PCM, and the other DSD. By recognising the completely different requirements in decoding each format, R4 keeps impressing us below the surface.

Specially configuring a pair of its DACs, and their ensuing analog low-pass filters (LPF), means HiBy are in a much better position to bypass DSD's problems and decode the format purely.

R4's DSD decode path benefits greatly from its LPF's stronger rejection of ultrasonic noise, in particular preventing single-rate DSD64's noise problems from contaminating the subsequent signal path.

HiBy might have gone in all in on the consumer market with R4, but that never stopped these innovators from respecting their audiophile roots. It then backs up that distortion and noise performance with all the luxuries that a modern music lover counts on.

Android 12 and Google Play Store's apps run smoothly thanks to a Snapdragon 665 CPU, for up to 11 hours on a single charge.

Seasoned audiophiles needing a compact and rugged travel companion will not find themselves missing their reference DAPs very much at all, given how high R4 gets you up the tree in performance. Similarly, newcomers will be treated to the full audio experience very quickly – and in painless financial manner.

If you've graduated from R4, be sure to check out HiBy's other marvels here too, or view all our other music players here.