As my Dad used to say, “the proof is in the pudding.” All the technology in the world isn’t worth a damn if it doesn’t sound good. Because this is the first ZED amp I’ve got my hands on in several years, and because it was a full range Class D design, I was really eager to get it hooked up in my reference system and listen to it. My reference system consists of a pair of high-end bookshelf type speakers, and a subwoofer system. Because of the unique attributes the Leviathan provided, I used channels 1 & 2 to drive my bookshelf system, and I used channels 3&4 and 5&6 bridged, each driving a 4 ohm woofer in a sealed enclosure.
I set the main speakers high pass crossover point to 80Hz, and the subwoofer channels were set to 80Hz low pass. The subsonic filter was set to 11Hz. After a quick gain matching of the sub channels, I sat down and began my listening with a true test for any amp running a full system, the Atlanta Symphony playing Introit and Kyrie from “Requiem Opus 48”. This track is an excellent test for how well an amplifier can reproduce complex choral voices and a full symphony orchestra at the same time. The Leviathan performed perfectly, and the result was a listening experience virtually indistinguishable from my studio reference amplifier. Needless to say, I was impressed! I moved on to more current but still difficult tunes like the soft passages and reverberance in the Cowboy Junkies “Trinity Sessions”. This recording was made with the band standing around a microphone in The Church of the Holy Trinity in Toronto, Canada. The recording captured the ambience of the room, and the ZED Audio Leviathan reproduced it with almost startling clarity! The process continued with me listening for any telltale signs of a Class D design, such as high frequency harshness, or added high frequency noise. I found nothing at all to complain about! In fact, the ZED Audio Leviathan sounds very much like my expensive studio reference amplifier in many respects. Which is to say, the ZED Audio amplifier is natural and realistic sounding, with plenty of power to handle dynamics and very quiet when it was supposed to be. All in all, the Zed Audio Leviathan is a really great sounding amplifier, regardless of topology.
On the Bench
After my listening had been completed, I connected the Leviathan to the brutally honest Cogent Audio Labs test bench, and ran my normal battery of tests and measurements. I’m happy to report the ZED Audio Leviathan exceeded its rated power at both 4 and 2 ohms, and frequency response was ruler flat from below 10Hz to over 20kHz.Signal to Noise was about average for an amplifier of this type, and crosstalk measured a very good -61dB. Distortion and noise were very low, below 0.1% at any frequency at 1 watt of power. The amplifier is well thought out, and the layout of the PCB contributes to the overall excellent performance. Of course the main benefit of a Class D amplifier is power efficiency, and in that regard, the ZED Audio design performs just as expected. Although no one generally quotes the efficiency of an amplifier at fractional power levels, the fact is, that’s where most of us use them. And that’s really where a design like this really shines, using about 50% less current than a traditional Class AB amp would draw at say, 10 watts per channel. As a result, the amp runs cooler, and places less of a demand on your cars charging system.
ConclusionI’ll admit I was skeptical when I learned this was a full range Class D amplifier, simply because I’m pretty particular about my music, and there have only been a handful of these that I actually like the sound of. Well, I’m adding the Zed Audio Leviathan to that list, because after listening to it, had I not known it was a Class D amplifier, I don’t think I would have been able to tell. The Zed Audio Leviathan sounds clean and natural, with more than enough power to drive almost any system to high SPL levels! The Zed Audio amp is well made, and the very flexible input section has been designed by someone who has clearly been in more than a few car trunks in his day. If you are looking for a reasonably priced, single chassis solution that is efficient, compact for the power it develops, and sounds great, you need look no further than the Zed Audio Leviathan.