Last Spring, I reviewed the HiFiMAN EF400 DAC/Headphone Amp, an impressively compact and versatile desktop unit.

The present review covers their newer, higher-end desktop model at $799; the HIFIMAN EF600 R2R & DAC Headphone Amp. It is a significant step up on several fronts as compared to the EF400:

More powerful: Max Power Output：5.12 WPC@32Ω balanced/1.8 WPC@32Ω
New DAC: It uses the new Himalaya Pro R2R DAC modules (one for each channel) with significantly lower distortion/noise and power consumption. (The power consumption is so low that micro versions of it are used in their new Svanar Wireless in-ear monitor ($499).)
New “tower case” design: 28.3 cm (H), 10.4cm (W) x 16.5cm (D) (11.14” x 4.1”x 6.5”) at the bottom, tapered to 10.4cm x 13.5cm (4.1” x 5.3” ) at the top: “The center of gravity is at the bottom, and cooling is at the top.” This design adds the convenience of using the top as a headphone stand (see photos).

The headphone out options are simplified/streamlined down to the two best: ¼’’ Single-Ended and XLR 4-Pin Balanced.
Bluetooth is now in play (for digital wireless input); just attach the included antenna on the back. (I did not use it in this review.)
More wired digital inputs (3): USB-A, USB-C, Coaxial
Analog inputs: XLR Balanced (pair), RCA (pair), for additionally connecting (for example) vinyl. (This is a significant addition.)

The EF600 retains the same Analog Outputs as the EF400: XLR (pair) and RCA (pair) for using the EF600 as a DAC only, and the same 4 Gain Settings: Low Gain NOS, Low Gain OS, High Gain OS, and High Gain NOS. (OS=oversampling, NOS=non-oversampling). Last but not least, it also contains a Voltage Selector (an orange switch on the bottom of the unit) for 115 V and 230 V: At the click of a switch, you can use the unit in most of the world.

Further specifications

Signal to Noise Ratio: 118dB（A-Weighted)
Channel Separation: 131dB±3dB
THD+N (Line out）: 0.0014%（-8dB)
Max Power Output：5.12 WPC@32Ω balanced/1.8 WPC@32Ω
Codecs (Bluteooth)： AAC/SBC/aptX/aptX-HD/LDAC
Weight: 3kg

Sleek elegance in looks and simplicity of use.

The tower design yields a modern touch expressing symmetry and elegance. With silver aluminum plates for the front and back and a smooth black curved top/sides where headphones can sit, it looks tasteful on a desk or table.

The front plate starts with the two headphone outputs near the bottom (in black), a thin rectangular volume knob a bit further up that allows continuous control, and then near the top two parallel columns for choosing the 4 gain settings and 4 input settings (USB/Coax, Bluetooth, RCA, Balanced). Each column is controlled by pressing a horizontal bar that cycles through the settings and lights up in green (for the input) and white (for the gain). The word HIFIMAN is displayed in large letters near the top.

On the back plate, the AC power connector and power switch are located near the bottom (you can use your cable), and then vertically moving up in the middle are the balanced and RCA outputs and balanced inputs. Finally, near the top are the antenna connector for Bluetooth and the other 3 inputs (USB-A, USB-C, Coaxial).

My use

I mainly used the Roon Arc App (on an iPad connected to the EF600 using a USB cable). This method allowed Qobuz, Tidal, and my home library to be accessed via my music server (located at home) endowed with a Roon core; this allowed such access from my office. I did, however, experiment with using vinyl (for analog input) and the Tidal Music App (on iPad, USB into the EF600), allowing Tidal streaming (more on these options later in this review).

Throughout this review, I used as reference headphones the HIFIMAN Audivina

Music

Peter Gabriel, I/O (December 2023) (24/96 FLAC, Qobuz).

In particular, the tracks “The Court (Bright-Side Mix),” “The Court (Dark-Side Mix),”

“I/O” (Bright-Side Mix), I/O” (Dark-Side Mix).

Hats off to Gabriel (vocals, synthesizer, rhythm programming, and composer of all the tracks) in his first new album release (December 2023) in over 20 years. His unique low-tenor voice (going back to Genesis) has admirably held up; he comes off as genuine, intimate, and thoughtful, and he chose a vast array of exceptional musicians to accompany him (from Brian Eno to the Soweto Gospel Choir). The recording quality, too, is outstanding, which the EF600 showed off with aplomb; the EF600 also convincingly illustrated how headphones can make “intimate/personal” sound even more so. The dead quiet and clarity are noticeable, and I think they demonstrated the superiority of the Pro version of the Himalaya DAC over its predecessor.

Of the musicians Gabriel chose to accompany him, I point out the remarkable conservatory-trained drummer/percussionist Manu Katché, who plays on 18 of the 24 tracks. (One might recall Gabriel’s big 1986 hit “Sledgehammer” from the album So; Katché played on that, too; he and Gabriel go back decades.) Katché’s snare and bass drums, in particular, are deftly tuned and used to effect; he seems to masterfully combine Gabriel’s desire to use electronics with the advantage of using acoustic percussion to create a natural—but highly structured—sound.

One of my preferred uses. (Photo credit: Karl Sigman).

Each of the 24 tracks is 12 pieces with two versions each (“Bright-Side” and “Dark-Side”). While I did not detect a bright versus dark spirit in the two, I did note more percussive complexity and delicacy in some of the “Dark-Side” versions of the tracks. For example, the bells atop cymbals and high hats in “I/O” or the gunshot-like sounds weaved into “The Court-Dark Side.” Parts of “Four Kinds of Horses” sounded very much, in spirit, like David Bowie’s “Lazarus” from his last album, Blackstar, about his impending death, hence “dark” in both cases. The EF600 helped make such differences evident and compelling.

Vikingur Ólafsson, Johann Sebastian Bach, Goldberg Variations. Deutsche Grammophon (2023). (24/192 Qobuz). I had already immensely enjoyed Ólafsson’s previous album From Afar, (2022), particularly the Bach Trio Sonata No. 1 in E-Flat Major; I liked how he dealt with Bach. I was excited when he released this Goldberg Variations album. He has an unusual touch and spirit, displays refined technique with creativity, and appears to take risks—resulting in a new and engaging interpretation of his own. The EF600 presented it nicely, well enough for me to enjoy in its entirety, but of course (piano is difficult), there is nothing like using speakers for this!

Back to Peter Gabriel. “Solsbury Hill” is from his first solo album, Peter Gabriel (1977). (Remastered 2002 version, Qobuz.) I have always liked that beautiful and uplifting song, with lyrics including “My heart going Boom-boom -boom.” It sounded super with the EF600, exhibiting exceptional “Boom.”

I finally listened to the remarkable cut, “Here It Is,” sung by Gabriel on the 2022 album Here It Is: A Tribute to Leonard Cohen album with his tremendously low "Cohen-like" voice; I did a double take the first time I had heard it (I had not looked to know who the singer was); I doubt Gabriel could have sung like that in 1977 when his voice was thinner sounding. Through the EF600, the sound was intimate, close-up, and mysterious, convincingly illustrating the ups and downs of life as Cohen intended.

Using the Analog input with a turntable

Some users may want to connect the EF600 with digital and vinyl input to have a complete system. I tried this out. I attached the analog output from my phono preamplifier to the XLR analog input of the EF600 and changed the front setting to “Balanced In.” It worked immediately.

For music, I chose Barbra Streisand’s Live at the Bon Soir from Impex Records (2023), one of my recent favourites. From my office, I had used the EF600/Audivina combo—as an analytical tool—when reviewing this LP (through my reference system at home) so that I could precisely hear Streisand’s banter with the audience; however, I had used it with the 24/96 digital version (Qobuz). But now (back at home), I could sit back and enjoy the vinyl version fully with headphones through the EF600, with its banter and music, and I did. In particular, the track “Cry Me A River” sounded vivid and engaging, a pleasure.

Using the EF600 when traveling

Near finishing this review, I had to leave NYC for a lengthy stay in Indonesia (where the voltage is 230V). I took the unit with me (not knowing if and how to use it there). I briefly overview how easy it was to get some music up and running.

I made sure to switch the voltage to 230V! I attached my iPad (wirelessly connected to the internet) to the EF600 the same way I would if using Roon Arc, but since I had no Roon Core (it was back in NYC on my powered-off music server), I could not use Roon Arc (yet).

I have a Tidal (and Qobuz) subscription, so I downloaded the Tidal Music App onto the iPad, logged in, and presto—then there was music! Thank you, Tidal. And it sounded great.

Note: Qobuz still needs to offer such an App, but (I am told) it will soon. Meanwhile, one could try using mConnect Player, but I prefer not to. I am now in the process of trying to transfer my home Roon Core to a new device here (then load it with my library via a small 1TB SSD drive), then using Roon Arc so that I will finally have all three using the EF600 while far away from home: My library, Qobuz, and Tidal. Easier said than done; stay tuned.

Summary

The EF-600 is an admirable new desktop unit that brings HIFIMAN second to none in this arena for $799. The several hundred dollars higher price than the EF400 is worth it if you can afford it. In addition to having even more features than the EF400, a superior “Pro” version of the Himalaya DAC, and a novel tower design that serves as a headphone stand, it yields cutting-edge distortion-free sound for a unit at such a price, is easy to use—and you can take it worldwide. Highly recommended.

Further information: HiFiMan