Lynx Hilo 2

This updated version of Lynx’s mastering converter offers a much improved touchscreen, a host of new filtering options — and the best D‑A converter performance we’ve ever measured!

When launched in July 2012, Lynx’s Hilo converter established a new benchmark level of performance that has endured for over a decade. Now, the company have raised that bar once again with a new, substantially updated version: the Hilo 2. At first glance, aside from a fashionable dark‑grey colour scheme replacing the original silver, and the 2 suffix being added to the name, the new model is visually indistinguishable from the old. But much has changed beneath the skin, all aimed at eking out even higher technical performance and delivering enhanced usability and functionality.

Overview

Users of the original Hilo will immediately feel at home, as the operation and connectivity are largely unchanged. This remains a two‑in, six‑out, mastering‑grade A‑D/D‑A converter, combined with an internal 16x16 digital routing matrix. The front‑panel touchscreen provides direct control and display functions, but a Mac/Win computer app can be used for remote control.

The front panel remains very minimalist, with just a standby on/off button, assignable rotary volume control, and quarter‑inch headphone socket. As before, every aspect of the machine’s configuration and operation is controlled through a large, colour touchscreen, but this 480x272‑pixel display is a major upgrade: now an IPS (in‑plane switching) type with capacitive touch‑sensing, it has been totally redesigned to be more responsive to touch, brighter, and with improved off‑axis viewing.

In my review of the original Hilo (https://sosm.ag/lynx-hilo) I noted that “my only difficulty was with the touchscreen interface, where my podgy fingers only needed to be slightly off centre of the relatively small virtual buttons on the routing pages to either get no response or activate the wrong source”. I had no such difficulties with the Hilo 2, which responded quickly, precisely and reliably to my every prod without my even thinking about finger placements. So, this new screen is a very worthwhile upgrade!

The new touchscreen is a significant improvement over the one used in the original Hilo.

As far as I can tell, the Hilo 2’s current firmware (v1.3, released August 2024) is derived from the most recent version for the previous model (v8.13), and the core functionality and graphics appear almost identical. One useful key difference that I spotted early on, though, is that the new converter hardware can be configured with a wide range of different linear‑ or minimum‑phase filtering modes. The excellent, 70‑page manual explains these different modes well but, as a quick overview, the minimum‑phase options mimic ideal analogue filters, complete with their potential for ‘time smearing’ and altered waveshapes due to different phase‑shifts versus frequency.

The linear‑phase options maintain the phase relationships between different frequencies (and thus preserve waveshapes), but introduce pre‑ringing to the impulse response (ie. the filter creates an output before the wanted signal arrives, which isn’t something that can happen in nature!). Some people argue that pre‑ringing is audible and accounts for the difference in perceived sound quality between analogue and digital systems. For those who subscribe to this view, the availability of minimum‑phase alternatives will be appealing.

Both ‘fast’ and ‘slow’ options are available for both types of filter, referring to the steepness of the filter slope. The fast filter modes essentially provide a slightly wider and flatter signal bandwidth, while the slow options start to roll off a little earlier but much more gently, and the impulse response ringing is of shorter duration and reduced amplitude as a result. Interestingly, there’s also a linear‑phase mode with an ‘apodising filter’ setting (see the ‘Apodising’ box).

Inputs & Outputs

Other than the front‑panel headphone socket, all I/O connections are made on the rear panel and are identical to the previous model. Stereo line‑level electronically balanced analogue connections are on XLRs, with monitor outputs on a pair of quarter‑inch TRS sockets. As with the original version, the analogue line input and output reference levels are adjustable, reaching 0dBFS for signals between +18 and +24 dBu to match professional equipment, or 0 to +6 dBV for consumer gear. The monitor outputs are also configurable for a maximum level of either +24 or +10 dBu.

The expansion slot accepts USB, Thunderbolt or Dante cards, with USB being the most affordable option.

Digital audio in and out is either via XLRs for AES3 or RCA phonos for S/PDIF. Both formats are active simultaneously for the outputs, but only one can be selected at a time for the digital input. A pair of Toslink optical ports is also...