Review: Schiit Audio’s all-tube Valhalla headphone amp and pre-amp†
A hot-running, heavy box with magic inside
I have owned my Schiit Audio (https://www.schiit.com) Valhalla headphone amp for a couple of years, though it seems like longer. It has become an integral component in my stereo system. It works as both a single ended-triode, output transformer-less headphone amp and as a pre-amp. First, it only takes one stereo input, through two RCA jacks, so a balanced configuration would require a different amp. Schiit has plenty to choose from if you’re interested. I haven’t tried any balanced pre-amps.
My first two advances beyond base-level audio ($100 headphones plugged into a phone via USB—Edifier headset for gaming, though I wasn’t using them for gaming but for work meetings) were the Valhalla paired with the Sennheiser HD650s I write about here (https://open.substack.com/pub/hanscox/p/first-good-headphones). For a source I think I was using the bargain basement and surprisingly good Surfans F20 DAP, a small, rudimentary hi-res music player that provides many of the same basic functions more expensive DAPs do, such two-way Bluetooth (DAC and sink modes), USB DAC mode, microSD card slot, a screen, and separate single-ended headphone and single-ended line-level jacks. I was excited, and they all sounded so good together, I knew I needed to keep them despite concerns about the expense (for the record, these are not high price point items, but they aren’t free, either).
Right now, I’m listening to a recording of jazz trumpeter Woody Shaw and his group performing at the Village Vanguard, coming from my Rega Planar 6 turntable with the Ania Pro moving-coil cartridge and a Rega FONO MC phono pre-amp, using a pair of Sennheiser HD6XX over-ear, open-back headphones (which I review here https://open.substack.com/pub/hanscox/p/review-sennheisers-hd6xx-open-back). The great thing about an analog amp/pre-amp is that I can plug any source with a line-level output, into it. Some DAPs (all I’ve tried) only accept digital inputs and so they can’t accept a turntable phono stage’s output. All the Village Vanguard jazz recordings I’ve heard have a similar sound, whether it’s this Woody Shaw album, a Kenny Burrell album, Joshua Redman’s Vanguard album, or Brad Mehldau’s Vanguard albums. The right side of the sound stage extends farther right than with any other recording type I can remember, and the left extends far left. This comes through clearly now, through the HD6XX’s.
The record as a source is providing lots of highs and lows that challenge headphones; constant cymbal crashes, snare hits, and acoustic-bass tones come through well on the Valhalla. And, even with a 300-Ω pair of Senns, I have the volume dial turned to about eight o’clock, full-down being around six-thirty or seven o’clock. The gain switch on the back of the Valhalla is in the “hi” position, for high-impedance headphones. I have a pair of the Sendy Peacock planar magnetic headphones, and the amp powered them to my satisfaction. Their nominal impedance is about 50 Ω, not far off that of the HIFIMAN HE1000 V2’s specified nominal impedance of 32 Ω, in case you were wondering about planar support with the Valhalla tube amp.
I listen now to the same turntable, with the same phono pre-amp and the same Valhalla as headphone amp, but this time I’m wearing Focal Clear MG open-back, over-ear and lovely-as-can-be headphones. The sound stage on these is very wide, especially with this 2021 reissue of pianist Bill Evans’ Trio ’65 LP. Here we have the demand of many audiophiles, that of having acoustic instruments. How are they rendered? The recording is comparatively old (and I will play newer music in digital format), but the fidelity is high. The piano is center left, the drums are close right, and the bass is to the left. Even this 1965 recording allows the acoustic bass to hit low on low notes. And the kick drum on the drum kit is solid and low. Every tiny sound of Larry Bunker’s brushes is rendered clearly by the Valhalla. If you want analytical, I’d say you get some ability to listen that way. If you want to get lost in the music, I’d say you can do that. I have the volume to where I estimate a live performance in a small venue, seated close to the piano, would place things. The Valhalla’s knob is at almost ten o’clock.
Switching to my Sennheiser 820 closed-back reference headphones, and, turning the volume so I can hear loud piano notes as almost uncomfortably loud (about 10 o’clock), the bass seems a bit woodier and rosin laden—the sound of stretched contrabass strings pulling on delicate wood bridge, top and internal bracing. The sound stage is deeper. I am a bit farther from the bass and drums. The piano sounds close. It is a more open feeling, and I feel more relaxed, having a respectable distance from the performers, in the sound stage shape. Chuck Israels’ bass is clearer than with the Focals. There is less low-end weight to it. Larry Bunker, using drum sticks, gives the snare some rapping and sends the cymbals spinning with sizzle, and all is crisp. Due to the age of the recording, Evans’ piano sounds as if it’s muddy and distorted compared to the usual sound of a newer recording of an acoustic piano. Notes sound smeared together. What does all this have to do with the Valhalla? Let’s compare the findings so far with some listening to some digital media with newer music.
Streaming the Tingvall Trio’s album, Birds, through the Cayin N7 DAP using Qobuz (https://www.qob.uz), the difference in the sound of the piano is immediate. Chords sound as they should, as groups of notes—melding together, yes, but not smeared across each other. Single notes sound richer and less like a honky-tonk piano (sorry Bill Evans, you were a great artist). The bass is deeper and still woody. With the volume knob at ten o’clock, the music is loud (these are sensitive Senns, 103 dB) and I hear the vocalizations of the pianist on my right. The sound is clear, undistorted. Turning the knob still further, to twelve o’clock, I hear more reverberation in the wood block(?) struck by the drumstick, and the piano begins to show some distortion on the loudest notes of a loud passage. The music is very loud, but I am comfortable, perhaps because I feel the depth of the sound stage puts the instruments a bit far away from me compared to the Focals.
Turning to Nirvana’s Nevermind album, with “In Bloom,” the clean guitar is every bit as soft lovely as I remember it from when I first heard it—only now I am hearing it, really hearing it clearly, for the first time. The overdriven guitar is the wall of sound that suffuses the senses with pleasure, that once shocked my world. But these reference headphones are not doing it for this type of music, that has such a personal history with me. They put too much distance between the music and me. Yes! As I suspected, the Focal Clear MGs brought the music closer to me, and provide a more solid, full-bodied low end. This is how “Smells Like Teen Spirit” is supposed to be heard through headphones. The band sounds much more musical than with the Sennheiser 820’s. I’ve never heard this song, playing at an over-sampled rate of 192 kHz, in such high fidelity. Perhaps the reason many people said they had trouble understanding Cobain’s vocals was due to poor equipment. No, I’m joking. I remember that moment in music history well. I think Cobain deliberately played on ambiguities in the sounds of phrases, and I think Radiohead’s Thom Yorke did that in his “Idioteque,” for example. At eleven o’clock, with the Focals (50-Ω magnesium drivers), the music is over-powering and I turned it down almost immediately. The Valhalla can drive most headphones louder than is healthy for one’s hearing.
I have read people who’ve said a tube amp puts “more air” into the sound, separating instruments more, or that it creates an “airier” sound. What I’ve found after spending some time with three pairs of headphones, is that the Valhalla, used as a headphone amp with the Cayin N7 DAP in class A mode, as source, creates a depth to the sound stage that is not there when listening straight out of the N7. Focusing on the beautiful, overdriven and effects-laden guitar solo in “Smells Like Teen Spirit,” straight from the N7, the guitar sounds flat; heard coming through the Valhalla, it has a third dimension—depth. The Sennheiser reference headphones are closed back, which I’ve read have a deeper, less wide sound stage. Putting the music through the Valhalla deepens the sound stage further, making Nirvana sound as if it were “like a patient etherised upon a table”—it makes it sound as if it’s being sacrilegiously mishandled with surgical tongs. With the open-back Focals and the open-back Sennheiser HD650’s this time, the already-wide sound stage gets more depth without placing the music too far away. The distance added to the solo guitar in “Smells Like Teen Spirit” creates more of an impression of being present for a performance than the flat, two-dimensional sound coming straight from the Cayin N7.
My favorite indie band is See Through Dresses.
Admittedly, I don’t listen to a lot of indie music. I’ve been told they sound like CHVRCHES, but I like See Through Dresses better because they’re more down-beat, more lofi, and more moody, less poppy, and they have gorgeous singing (two vocalists who take turns on successive tracks, one man and one woman—my apologies, I cannot find their names at the moment); and synths, drums, bass, and guitars. What more could I want in an indie band? Their “Diamonds,” a gem from their album Horse of the Other World, sounds like a wall of strung diamonds jingling together in a shimmer of sound. The guitar sounds are out of this world, and the synth is like a heart that has been beating for a million years, leaking its lifeblood in forsaken love. That’s Horse of the Other World in a nutshell, and one of the reasons I love See Through Dresses. Their tape came with a digital download code! And I got their LPs. But anyway, I’m listening to Horse of the Other World in digital format, on the Cayin N7, through the Valhalla headphone amp, with the Focal Clear MG’s. The volume knob is at 9 o’clock, and things are happily loud. The Focals have the wide sound stage, and the Valhalla adds depth and “air”—yes, I’ve come to think that a good tube amp does put some air into the mix and helps separate sounds that are separate. It gives a third dimension to guitars, as it did in “Smells Like Teen Spirit.” Clean, chorused and reverbed guitars, especially, benefit from the added depth and air of the Valhalla. “Pretty Police” on Horse is a great example of this and features the female vocalist (again, my apologies for forgetting names!).
That’s it for now. The Valhalla will likely make appearances in future writings. Schiit Audio (https://www.schiit.com) make great stuff. My stereo has…let’s see…six Schiit components including the Valhalla…including, also, three of their Aegir class-A (sort-of, yes, that’s how they put it – or something like that) power amps. They’re for my active tri-amping setup. But that, as it is said, is another story. I recommend the Valhalla for a desktop headphone amp. Just remember. It gets warm, very warm. This has been a discussion of its virtues as a headphone amplifier. I use it mainly as the preamplifier for my home stereo system. That is something I’d like to cover in another article. What do you use for a pre-amp? Do you use an integrated amp? Maybe I’ll write up something about the Dayton, hybrid tube, integrated amp I started with. It’s been a lot of swirling water under the bridge since then, and here it sits, a testament that humble and relatively casual beginnings can lead to quasi-obsession.
†This post is posted early in memory of my friend, Rob, who recently left this stage. I’m reminded to do things while they can still be done, so why delay this post’s publication?