Einar Sound VC-01i Balanced headphone amplifier in Review – balancing and unbalancing the equation

When you’ve decided to clear your desktop, shed the headphones/turn off the speakers, and part the waves of a blistering commute to work, you insert inner earphones into your bus/train ride to work. But after a drudgered day of officing, places like your desktop, or your bed look and sound better for kicking back to relaxing music. If you cannot cajole your smarter half into saving up for a nice speaker setup, good headphone systems can be had for relative chump change. Canadian audio company, Einar Sound, offer both balanced and single-ended headphone bliss with their VC-01i, an amp which attacks sound quality and relative budget in one fell swoop. Feel free to discuss this review of Einar Sound’s VC-01i in our forums.

Input impedance: 20KΩ
Output impedance: less than 4Ω
Frequency response: 15Hz – 40 kHz (-0.5dB)
Signal to noise ratio: >97dB
THD: less than 0.001% 18mW/300Ω
Channel separation: >80dB 10kHz
Maximum gain: 12dB
Output power (balanced): 380mW/300 Ohms, 700mW/60 Ohms
Output power (unbalanced): 200mW/300 Ohms, 400mW/60 Ohms
Input: 1 Pair RCA + 1 Pair XLR
Output: 2 pairs 1/4” headphone jack +1 pair XLR
Power dissipation: less than 20W
Power requirement: 100-240VAC/220-240VAC
Dimensions: 21*16,5*5 cm
Weight: 1,86 Kb

Build and Package
I almost feel silly typing the above title simply because almost every production balanced amp is ostentatiously large and carries an Ian Thorpe footprint. Amps have to survive the bus ride to their destination and almost always do. The VC-01i is packed safely in a triple sandwich of pressure styrofoam. Other than the amp, there is nothing but a few sheets of paper – had I read them, I’d have realised than one is the manual and the other the guarantee – an overall sparse lining to an otherwise great amp. You will have to pick up your own IEC power cable and RCA/XLR input cables – an extra trip which may make it even more obvious to that sleuth who calls herself your wife that you’ve emptied part of the bank account on a new toy. Don’t worry though, Einar have a few tricks up their sleeves to help you out in your home life.

The VC-01i is hardwared by no fewer than 30 bolts which solidly fasten its 6 aluminium plates together. It is made in China, and looks like it, but it is pretty solid with a supporting inner skeleton protecting the power supply, but here is a little ‘give’ in the upper and rear plates.

Its 21 * 16,5 * 5,5 cm footprint is the size of a large netbook computer and is at least twice as thick – in other words, you won’t be hiding it. Sit your wife down with your favourite headphones, and discuss ‘new toy syndrome’ stuff while she rocks out – trust me, it is easier this way. She can even fiddle with the oddly finished volume pot, quipping about its size and off-kilter mounting – it won’t matter. It sounds good enough that you can call it an investment. Besides, that volume pot is just _so easy_ to turn, in fact the entire amp is as easy as pie to operate blindly. The placement of the ON/OFF switch and other toggles in particular is important. Thankfully, Einar have discovered the secret of success. The amp’s front is dominated by that large volume knob on the right and then decorated by the smaller circles which stretch to the left: dual XLR and TRS outputs. Between them is a tiny RCA/XLR input toggle which is easily spotted by even the blurriest of morning eyes, and at night, it is denoted by a small glowing led power indicator. The power switch is located at the furthest left position on the back and is is as easy as duck soup to switch on or off. Einar’s ergonomic are almost spot on – there is simply nothing to mix up; from the volume pot to the placement of the rear inputs and front outputs, the VC-01i is a joy to use. That said, for large-fingered oafs, removing headphones and input cables from the XLR terminals can be somewhat of an ogre’s task since there is very little vertical clearance below to the desktop or other audio component.

Finally, the VC-01i vents from the top rather than bottom which is both a blessing and a curse. Let’s start with the curse: dust collects more easily inside. It also means it isn’t wise to stack anything on top which would be big enough to block the vents, and using the amp as a dinner mat is right out. It’s not like the VC-01i gets really hot – it doesn’t. But its grill warms up nicely with good music. On the blessing side, it doesn’t shed dust onto gear below it and as heat naturally travels upward, the cooling of internal components is always physics-friendly. One other point to watch out for: the VC-01i has very small silicon feet and a large front face plate. This combination means that there is as little clearance as little as ~1 mm is all the clearance afforded by the VC-01i’s large aluminium front plate. Look out for scratches and dents on nearby equipment.

The VC-01i’s amp circuitry is what I will dub, ’hybrid-balanced’. A ‘true’ balanced amp sports dual power sources and generally, a much higher price tag. The VC-01i shares one power supply, but splits it between separate voltage regulator circuits. To be honest, other than placebo, there may be very little advantage to a real balanced circuit in the VC-01i’s chassis.

In many ways, the VC-01i is two amps in one. Firstly, it can animate any normally terminated headphone from either of its stereo jacks. Right, so there are two, but the VC-01i only outputs to one at a time and there is no provision for running balanced headphones from the dual TRS jacks. Anyway, in either single ended or balanced operation, there is a lot of power distributed into any headphone. Balanced of course carries nearly double the output power, but I’ll be damned if anyone needs more power than than what bursts forth from the stereo jacks unless they are running AKG’s K1000 ear speakers.

Whether you drive the headphones from the either of the TRS outputs, or from the XLR terminals, the amp can be fed from either RCA or XLR inputs. In other words, you don’t need to own a balanced source in order to enjoy the upgraded power, and to a lesser degree, the control which balanced in and out afford headphones.

Both balanced and single ended outputs run concurrently, so if you have another set of ears, you can share your music or movies with another person. Note, however, that the XLR outputs are much louder, so you’ll have to do the maths between headphones to decide which will eat at the XLR’s and which will plug into the TRS.

Many balanced headphone amps are noted to perform sub par in single ended mode. I have to disagree somewhat with that assumption – at least as it applies to the VC-01i – this amp sounds great in either mode with great control and incredible resolution. Balanced operation does add a new dimension in finesse and technical superiority to headphone listening, however. Just don’t expect your Sennheisers to turn into Beyerdynamics.

Audio Performance
The VC-01i is Einar’s debut amp and is very, very good. It hits the very tempting price point of 599$ which straddles right between top-of-the-line single ended solid state headphone amps and typically priced balanced amps. There are several key areas where it performs above reasonable expectations and a few where it performs a little below them.

Firstly, the VC-01i has very good balance between its left and right channels, but at very low volumes, suffers what is typical of ALL volume pot amps: imbalance. It isn’t bad; even with sensitive headphones and earphones, there is enough headroom that nearly all earphones can achieve balance without rupturing eardrums. Of course, at normal listening levels, there is no imbalance problem and the VC-01i generally operates within 0.0 – 0.3 decibels of difference between channels, the lower number denoting balanced operationi. Apropos of my experience, there are very few full sized amps which hit as good a balance between left and right channels though they advertise differential output of <0.1 decibel.

The VC-01i’s best face smiles toothily when sucking juice from a balanced signal and spitting that into the XLR of a good headphone. It is a smooth-talking amp with deep texture and very good dynamics. But it gets on with music without excess verve. It favours orderly presentation and tight instrument placement. Its stereo image is wide, but not drowningly so. It is very much like a mid-sized concert hall, and in balanced mode, gains an instant extension. Of course, I must attach the proviso that the VC-01i isn’t a hot or throaty amp; it adds very little of its own colour even to its excellent midrange.

Bass lovers, Einar’s amp will really bring alive your low impedance headphones. I’ve used a couple with the VC-01i including the K701 and DJ1Pro, and both are bloody brilliant. If you’ve not heard the bottom in either phone, you will. My DJ1Pro are single ended, and in my estimation, are ‘hard to drive’ headphones: there are very few sources/amps which bring out the depth of bass they are capable of, but the VC-01i is a very proud member of that very elite group. There is an abundance of dry, beefy, throbbing bass tones which the DJ1Pro surprised me very much with. My other favourite, the 600Ω DT880 is obviously not a low impedance headphone; neither is it sensitive. Its voice coils move wonderfully when powered by the VC-01i, but not with the same degree of transformation as the DJ1Pro. In single ended mode, its frequency response remains largely unchanged other than a slight deepening of lower bass. In balanced output, the DT880 keeps the lovely deep bass, but gains a richer left to right presentation, throwing instruments more succinctly into the newly added concert hall extension.

In some ways, this solid state amp sounds like an energetic tube amp: it is smooth, bordering on nonchalant, but always well-extended. Low percussion, strings, and bass near fibrous detail, but halt just one stop away. The VC-01i has a fit-all sound signature. Warm where it needs to be, it flatters a diverse collection of tunes without taking sides. There is very little effluence of personality inflicted on any part of the sound spectrum. Up top, there is a very small amount of roll off, but only bats would worry; for all intents and purposes, its minor roll off of ~2 decibels is inaudible to humans.

There are plusses and minuses to such a neutral sound signature. On the positive side, music will sound as close as possible to the recording and sure to please the naturalist. On the other hand, those who want a little distortion in the signal to warm up the sound or to eschew thick sound may want to look for a darker, thicker sounding amp. My opinion is that it is lovely, and especially adapted to every sort of music. It doesn’t charm anything, but it fits in any sized shoes, knows the steps to every dance, and find sure footing on all side roads.

Finally, the VC-01i has a very low noise floor. It isn’t on par with good portable amps, but as long as you can rid your audio rig of ground loops, Einar’s amp is dead silent with all headphones at regular listening levels. Sensitive earphones, however, will hiss, but with proper grounding, very little. And, Einar have also done away with ON/OFF thump which plagues sensitive headphones; music just jumps into and out of being.

Chart Disclaimer
This review’s RMAA measurements reflect the performance differences inherent in the VC-01i when loaded by a variety of headphones and when unloaded, driving pure signal. All signals are volume-matched and captured by an Edirol FA66. The following measurements reveal only input/output differences in Frequency response and stereo separation. The top two compare unbalanced RCA inputs/TRS with XLR input/output while the bottom two compare XLR input and TRS out driving a variety of headphones. For more Right Mark Audio Analyzer (RMAA) measurements, follow the same VC-01i Review thread in our forums.

Sound Conclusion
Being surprised by the performance of a 600$ dedicated amp is hardly news. It’s just that the VC-01i happens to host two output circuits: single ended AND balanced and drive each very well. Both sound great, but balanced operation edges single ended out especially in detail retrieval and stereo imaging. At its base, there is a wonderfully black background for all headphones, and just a little bit of noise for earphones of almost any shape and size.

In terms of resolution, the VC-01i is excellent. Even very low impedance earphones can’t stymie its output and the story only gets better as headphones get properly big and heavy. If you have a relatively low impedance headphone such as the Ultrasone DJ1Pro, you will be surprised by an incredible low, taught bass and as the voltage load grows with headphones such as the 600Ω DT880, the VC-01i puts out smooth, beautiful colours. There is heaps of power to be had, heaps of control, and heaps of refinement. But if you are looking for colouration, for pizzazz, you may have to look elsewhere.

My questions for Einar are dominated by the quizzical placement of two TRS output jacks when only one can be used at a time. The sight of two puts the heart aflutter with the possibilities. Sadly, there simply are none. Apart from that, this 600$ amp is a great deal. It isn’t endearingly pretty, but it earns accolades for powerful, but neutral performance and great ergonomics. If 600$ is too steep, Einar Sound also make a 399$ version of this amp which shares most of the same circuitry and function.

Headphone Amp Summary
Title: VC-01i Balanced Headphone Amplifier Developer: Einar Sound
Reviewed Ver: VC-01i Connection: IN: RCA/XLR OUT: XLR or TRS
Price: $599.99 Application: Desktop/HiFi
  • Great price/performance ratio
  • Nearly perfect ergonomics
  • Excellent audio performance
  • Concurrent use of TRS and XLR outputs
  • Not much clearance
  • Why two TRS jacks if only one works at a time?
  • Construction quality trails some other manufacturers

Headphone amps and DACs help your headphones get the most out of their transducers. Take a look through our headphone section for suggestions of good upgrade/sidegrade options, and our headphone amplifier section for suggestions on how to wring out the best performance from your beloved phones.

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