Disclaimer: The H1 in this review is on load directly from COS Engineering. The H1 goes for around €2,500. You can find out all about it here: COS Engineering H1.
Finding an integrated DAC / headphone amp as restrainedly designed as the H1 isn’t easy. Finding one as restrainedly designed that also performs can be a bugger. Which, of course, makes getting excited about the majority of modern integrated DAC/headphone amps another bugger. Lynx’s HILO has spoiled me. It’s spoiled me because it converts everything digital to analogue, and converts everything analogue to digital. No questions. After a short evaluation I ponied up. Gladly. Its warmish, rich-ish headphone output is reminiscent of an iPhone 4. For me at least, that means lights out for practically every mains DAC that comes across my desk.
The H1, however, is an anomaly, in some ways evoking HILO’s best DAC bits, in many ways tripping beyond them.
COS designed an easy-reading manual that explains basically everything in simple, clear English. Better yet, its hardware interface follows suit. A long press of the oversized attenuator wakes the H1. Another long press puts it back to sleep. Hard OFF/ON is controlled from the rear. Rotating the attenuator ups or downs the volume by jumps of 0,5 dB. As far as digital attenuators go, it is one of the best I’ve tried: easy to turn, wobble-free, smooth. It is also impossible to miss. Attenuators this large, this ergonomic don’t exactly grow on trees.
In fact, because it is so damn big, you can be stumbling drunk and still use it. Strangely, the H1 can skip a half step in favour of a round number, 1dB instead of 0,5dB. The H1’s only other notable anomaly is the nomenclature behind its digital input menu. It goes something like this: USB, OPTICAL, RCA, XLR. It should be: USB, OPTICAL, COAXIAL, AES/SBU. USB can be switched from 1,1 to 2,0, and appears to perform flawlessly when plugged into my MacBook Pro, but, like so many USB devices, triggers my 2012 iMac. Measurable performance between the two differs by as much as 20dB SNR and 10dB DR.
By the way, check out how thick its chassis is. I measure almost 4mm, or almost twice as thick as the HILO’s chassis. It is the most solid integrated chassis in a mains DAC/headphone amp that I’ve yet tried, which is a testament to the effort COS put into making the H1 solid, tough, and engineering it for the long haul. Its flat feet fit solidly on proper desks, and its rear input array sits in a reinforced, recessed well. That makes it nice to photograph, and protects cables in systems jammed up against the wall.
The H1 is a tank. Unlike a tank, it gets along with civilian life.
Digital Input Sampling Rate
Total Range Accuracy
USB x1, Asynchronous 1.0/2.0; SPDIF x 1; TosLink x 1; AES x 1 Optical / RCA / XLR: up to 192K PCM 24 bits & DSD64 (DoP) USB 1.0 – up to 96K PCM 24 bits
USB 2.0 – up to 384K PCM 24 bits & DSD64/DSD128 (DoP) 24-bit DAC x 1 (up to 192Ksps, 24-bit)
192 steps by 0.5dB/step 96dB
Within ± 0.1dB
Supports 2 unbalanced headphones or 1 balanced headphone
Frequency Response THD+N
Headphone Impedance Full Scale Output
Frequency Reponse THD+N Signal-to-Noise Ratio Full Scale Output
Disply Weight Dimension Power
+ 0dB, – 0.5dB (20Hz ~ 20KHz)
< 0.001% (- 100dB)
(192Ksps, 24-bit, 20Hz ~ 20KHz, A-weighted, 16 ohm load, 2Vrms) > 110dB
(192Ksps, 24-bit, 20Hz ~ 20KHz, A-weighted, 16 ohm load, 2Vrms) 16 ohm and up
Unbalanced : 6 Vrms; Balanced : 12 Vrms
+ 0dB, – 0.5dB (20Hz ~ 20KHz)
< 0.001% (- 100dB) (192Ksps, 24-bit, 20Hz ~ 20KHz, A-weighted) (192Ksps, 24-bit, 20Hz ~ 20KHz, A-weighted)
128 x 64 pixels white OLED
260 mm (W) x 250 mm (D) x 60 mm (H) (boot is not included) 100 ~ 240VAC
Normal Operation < 20W
Standby 0.5W (typical)
Sound and more after the jump: