HifiMan Susvara. Five amps. No witnesses.

by Dawid Grzyb / February 3, 2020

HifiMan Susvara isn’t an ordinary headphone product. The word on the street is that it actually enjoys company of proper speaker amps more than regular headphone decks. This subject got me interested enough to conduct my own investigation, enabled by several devices deemed as fit for the job. Enjoy!


Even though today’s article isn’t a typical HFK story, it was on my to-do list for months. Not only this, even though it should originate as a regular journo assignment strictly related to headfi, it didn’t. Far from it. My privy track record with headphones is quite uncomplicated. Many enthusiasts roll with multiple costly cans, amps and the lot, which labels my own rotation in this sector as anything but crazy in comparison. In spite of familiarity with a fair share of expensive headphones over more than a decade, I’ve always owned just one primary model with one main amp. Let’s call it my personal bias towards keeping things simple in this realm. It all started form Sennheiser HD 800 purchased shortly after its official release and then paired with the no longer manufactured Audio-gd Phoenix balanced amp. This setup gave me lots of joy and was the first serious one I’ve built. At some point Sennheiser’s open-backed game changer got stomped by Fang Bian’s about three times as costly HE-1000v1 model, which to my ears did most things substantially better and was less fussy about associated hardware.Perfect happiness achieved with the planar HE-1000v1 flagship truly got me into thinking that things couldn’t get any better. Simply put, at that time sonic level reached was high enough to leave any craves for more performance at the door. No experience with cans located upper in the food chain rendered me clueless about what the word ‘better’ could actually stand for back then. As per usual, it was just a matter of time for this to change.In July 2017 I got my hands on HifiMan’s freshly launched HE-6 successor Susvara, no less notorious due to the very same inefficiency reason. Back then two headfi amps – Pass Labs HPA-1 and iFi audio Pro iCAN – allowed me to understand how much better HifiMan’s latest specimen was versus my HE-1000v1. In spite of the newcomer’s superiority on every count, its sticker beyond my reach pushed me towards the latter’s better version two instead. This transition left me quite satisfied for some time, but withdrawal symptoms past Susvara’s departure grew stronger and stronger one day at a time. Subconsciously I knew that this chapter was far from over. Finally, along with my cohort Matt the Forza AudioWorks guy, we managed to finance HifiMan’s flagship planar model together. As two chaps fully aware of Susvara’s usefulness in our daily struggles, we did the wire with no regrets.Now let’s fast forward to January 2019 and the article about Bakoon AMP-13R. In short, if I had to point my journo finger at a single best-sounding amplifier I’ve heard in controlled environment thus far, this marvel would land the top spot easily. Not a hair but a fair bit below it I’d position Thöress F2A11 alongside Trilogy 995R/915R. Of course all listed items sport their own unique sonic flavours, vary in topology and are meant for different loads. Nonetheless, the smallest and most affordable of the group, that would be the Bakoon, on sonic exquisiteness and overall excellence is second to none, not even to far more powerful, intimidating, phenomenal by my standards and almost ten times costlier Trilogy’s three-piece set. Now let that sink in. Done? Good, let’s carry on then.Even though both HifiMan Susvara and Bakoon AMP-13R reviews started as regular assignments, each quickly morphed into an unforgettable experience that doesn’t let go easily. Just as I knew I had to have HifiMan’s top planar model sooner or later, the feeling towards the Bakoon was very much alike. Upon its return several months later, I already had Susvara nearby and wasn’t afraid to use it. What was off the table during the first AMP-13R rodeo, now became possible. These two extraordinary products (both awarded with my ‘Victor’ badge) under one roof at the same time, eventually introduced the ‘what if?’ question. Let’s say that curiosity pushed me to map their conjoined service. Alas, no dice, the petite deck ran out of juice, most music it served at SPL far below party level. ‘Aw shucks’… or so I thought.Then Bakoon’s main man Soo-In Chae stepped in to inform me about the AMP-13R’s adjustable gain feature. That gorgeous red knob pushed for several seconds granted me access to the machine’s handy sub-menu, wherein I happily unlocked 22dB of gain for its 6.3mm out driven by the same posh circuit. Now this socket was of power output on par with speaker terminals just across the enclosure, which spelled 25wpc into 8Ω… for headphones <a maniacal laughter emoji goes in here>. Upon asking Srajan about the super-secret gain option, I could almost see his virtual chuckle. The man told me that he actually tackled this subject in his own Bakoon writing, but clearly I had skipped this bit. ‘Works awesome’ was how he described the AMP-13R/Susvara combo in one of his mails, whereas yours truly was blown away by it enough to pen today’s story. But there was more to it still.A number of proud Susvara owners feed these cans via regular power amps, supposedly with nice results. Several such machines available plus the Bakoon and two regular headphone decks, all led to today’s skirmish, additionally fueled by my own desire to know what’s all the big fuss about these cans and full-sized speaker devices. Multiple questions demanded answers. Was a 100wpc hardware really a necessity for Fang Bian’s inefficiency bastard? Or an overkill driven by the latest fad propagated among headphone communities? Perhaps something of smaller power output would still grant me access to the aural heaven? And where regular headphone decks would land in all this?


The methodology was utmost simple. My fidata HFAS-S10U sent digital music to the Lampizator Pacific DAC (KR Audio T-100/Living Voice 300B + KR Audio 5U4G Ltd. Ed.), which then fed one of several products; Bakoon AMP-13R, Kinki Studio EX-M1, Thöress DFP, Trilogy 925 and lastly iFi audio Pro iCAN. GigaWatt PC-3 SE EVO+ plus GigaWatt LC-3 EVO and several LessLoss C-MARC cables handled power, whereas iFi audio’s 3x Mercury3.0, iGalvanic3.0 and micro iUSB3.0 were on the USB duty. HifiMan Susvara connected to each amp separately via Forza AudioWorks Noir HPC MK2 headphone cable, terminated with a handy 4-pin male XLR. At this junction it bonded with one of two separate pigtails, finished with either a regular 6.3mm jack by Furutech or four BFA-styled banana plugs. This meant driving this report’s load from listed integrated amps’ speaker taps directly, whereas regular headfi decks were operated as per usual. What could go wrong?Five machines on standby required some planning. All this hardware split into two smaller groups seemed to be the most reasonable approach. At first Susvara cans were used exclusively with three regular integrated amps, just to flesh out the best companion for this notorious specimen. Once that base was covered, my top pick was then put up against the remaining two headfi decks. Here’s what went down.It’s worth to point out that neither integrated product sported a separate headfi route inside, not even the Bakoon. Their main circuits daily used to drive speakers, this time around were engaged for headphones. This clearly worked to my advantage, simply because each product was already reviewed at these pages, hence well-known. All products used on multiple occasions with various speakers led me to thinking that, at least with a specimen as tonally balanced as Susvara, I should’ve heard three core flavours as distinctive as they were familiar. Not only I wasn’t wrong, but on this count today’s comparison was over well before it even started. Involved amps’ potency in driving this story’s key load could’ve been the only caveat, but in reality it wasn’t. The Bakoon AMP-13R’s volume knob fixed at 35/59 and high gain, Trilogy 925’s locked in at -30/63dB and the EX-M1’s at 80/255 and low gain, all resulted in quite similar SPL and there was still plenty headroom left in each case. Put shortly, all three machines fed Susvara very effortlessly, with authority and to deafening levels upon demand.The key disparity between integrated decks narrowed down to their sonic quality exclusively, nothing more and nothing less. Each behaved accordingly to its profile already mapped by yours truly. To make it short and understandable, the Trilogy 925 was the most gravitational and round, Kinki Studio’s EX-M1 emerged as the most chiseled and slim, whereas the Bakoon AMP-13R secured the position of the most balanced hardware of them all, but stood far closer to the Chinese than the Brit. It’s safe to say that three different voicings clashed and each worked truly well with Susvara, but one particular product was far superior versus the remaining two on sheer refinement and seasoning.The AMP-13R put up against the EX-M1 invoked a major déjà vu. At first glance these two specimens seemed voiced as alike with Susvara now, as they were with floorstanders months ago. Both amps hit like a truck, went impressively low, were explicit, fit, accurate, smooth and tonally very linear. Still, important disparities emerged once the accommodation phase settled in. The EX-M1 was slimmer and rendered all virtual outlines more chiseled. The Bakoon the same job executed in texturally less pale more complex fashion and easily was as articulate whilst doing so, plus its upstairs decayed longer, was of finer grade and felt more substantial. It was also less icy, more muscular, tangible and organic, but at no cost. On the contrary in fact, this petite marvel is a resolution monster capable of extracting even tiniest dust particles out of its hauntingly black background like it’s nothing. But most importantly, its delivery is exquisite enough to shift one’s focus from single bits bluntly magnified to the far more important elegance and charm; two major attractors of this particular machine.Over the years I’ve learnt that top shelf resolution is subtle by nature. It doesn’t seek attention but simply occurs supportively alongside everything else. It just is. In this context, the EX-M1 did well but had a fair bit of that ‘in your face’ flashy attitude, tension and excessiveness, whereas the AMP-13R materialized even more virtual dots more effortlessly, tastefully enough to keep detail overload at bay and also felt more substantial. This alone made a helluva difference in how both amps spread their word out, but major disparities between them didn’t end there.The EX-M1 with Susvara was exceptionally snappy, stunningly immediate. Rapid string plucks and hand claps this team literally shoved into my ears with no apologies. Thunderous strikes appeared out of nowhere, invoked major scares and faded as swiftly as they appeared. Quickening of this sort with regular floorstanders is a very rare thing, but Susvara fed by the Chinese deck had this plenty of. Many ears not adjusted to such bravado would most likely find it intimidating at first. But several tracks in, the at first hostile sensation naturally flourishes into exciting addiction, which leads to music intake very much alive and driven. This virtue alone is a very potent motivator to rediscover one’s playlist one track at a time, yes, in search for those refreshing lightning strikes rather felt than heard.Headphones naturally remove our listening rooms from the equation, thus are less prone to bass boom or wobble; two culprits responsible for smear in the upper band and clarity loss. The EX-M1/Susvara hit squad didn’t even know what that meant. It just kept going and going accordingly to SPL increase and remained perfectly clear regardless. When my ears screamed ‘ouch’, naturally I went no further, but the fact that this was possible with no drawbacks, was damn impressive. The Kinki’s internally slim posture and agile attitude boosted the already extremely speedy experience. At this point I wondered; how many Susvara owners have heard these cans this wild and capable of stunts this bold? And then, the major twist came.In spite of far lower power output, the Bakoon easily scored as equally high notes on torque, air propulsion and thunderous jabs as the EX-M1 did, but pushed even further. The former’s key advantages resurfaced in form of grander more alive spatial landscapes, even lower reach and more civilized approach manifested via outlines as equally explicit, yet filled with finer, costlier, posher and more humane pigment. Put shortly, the Bakoon had all the EX-M1’s best skills and some of them it in fact had surpassed. However, on refinement, maturity and ability to showcase music from utmost fetching side, Soo-Inn’s deck had the far upper hand; it was happily obedient towards repertoire in demand of calm meticulous touches instead of wild slams and crack. The more nervous and juvenile EX-M1 wasn’t to the same extent. Minimalist acoustic guitars, celli, double bass or sensuality encapsulated in gentle female vocals, very easily showcased the gap that formed. Several hours in, the Kinki yet again struck me as a product which would very much like to be as tastefully voiced and posh as its rival, but it simply couldn’t. Just as it was the case with these two amps on duty with floorstanders months back, this time around different refienment tiers clashed yet again. One was clearly better.I can’t say that the Kinki Studio EX-M1 got beaten enough to be viewed as inferior, not at all. The team it formed with Susvara was far too good to jump to such conclusions. Nonetheless, the AMP-13R was at least one step ahead of the Chinese on every count I could think of, which is why the latter had to step down and make room for the next contestant – my Trilogy 925. During this fight several things happened I truly didn’t see coming. The British integrated served with dozens of different speakers, DACs, cables and many other products. Until recently I naturally thought that my knowledge about this machine’s virtues and limitations was an investigation closed for good, but Susvara proved me wrong.Trilogy 925’s profile lists the following descriptive measures; roundness, authority, calmness, on-stage presence, spatial generosity, gravity, moisture, textural earthiness and tonal balance a fair bit below the middle. This list can be also narrowed down to the 925’s voicing quite opposite to the EX-M1’s flavour. These two machines seriously are not alike, their only common ground would be potency on filling my crib with large virtual landscapes. The Trilogy’s personality is very expressive and enjoyable, although always strong, at least that’s the usual status quo with multiple speakers. But most interestingly, Susvara toned down the 925’s own input substantially, the notion of these cans in control over this deck struck me from the get-go. Early on I didn’t quite recognize my trusty integrated as it sounded far more fit, fresh and alive than it normally does. The new experience was as new as it was entertaining.I got my senses back past transitioning from the 925 to AMP-13R for the first time. The latter was quicker, a bit stiffer, spatially grander, more explicit, insightful, open, less dense and not as round. Naturally the Brit felt slightly veiled, enclosed, darker and less shiny still. It emphasized textural warmth and chunkiness, whereas the Bakoon did the same job in more organic and moist fashion; less syrupy but very much complex and alive. If the 925 was a person hitting the gym one to two times a week habitually, then the AMP-13R would be a fitness fanatic who’s been doing that three times as much for a decade or so. Picture a healthy muscle-to-fat ratio versus each muscular fiber visible under paper-thin skin and nearly all fat burned off. Let’s not even go to different commitment levels towards the same workout.The 925 was milder and calmer versus its more immediate opponent, which of the two pushed more air within created virtual spaces. But here’s the kicker; although perfectly sensible, the difference between both products wasn’t of night and day on quality. With Susvara, the 925’s own voice toned down translated to the effect more balanced than it usually is with this amp. The Brit sounded gloriously smooth, gentle and soothing, but also more effortless, lighter and upon demand significantly snappier than it does normally.The 925 exploited as a headfi deck morphed from a very much situational product in need of carefully matched companions, to a proper do-it-all headphone case of top shelf quality and age. If used like so it was still expressive and focused on pleasure more than hi-res, but also with most its drawbacks left at the door, which substantially elevated my privy listening experience. Its voicing tamed this much with Susvara netted grand overall sonics, that was the bottom line. Guilty as charged, I’d still easily pick the more balanced and technically quite unbeatable Bakoon, however disparities between both products involved more apples and oranges than anything else. But most importantly, as much as I enjoyed the EX-M1’s shove, crack and torque, the sportier than ever and more humane 925 had the upper hand on aspects related to music itself and its beauty, which my ears favoured more.At this point my to-do list included Pro iCAN as a spot on reality check tool, plus Thöress DFP line stage used solely as a headphone device. Both products already fought against each other with Susvara and two other cans thrown in the pit. This story you can find here. The important bit now is how the DFP did versus the Bakoon, which is a bit complicated.In general classification the DFP is tastefully executed stunning headfi amp; very energetic, nimble, airy, silent, with surprisingly feisty and tight bass, smooth, tangible, exceptionally clean, generous on harmonics and not overcooked in any way in particular. By cutting distance to the closest virtual sound sources, and then locking them all in artfully presented generously oxygenated bubble inside of a listener’s head, the DFP renders spatial images not quite comparable to any other product in this report. With Susvara connected the sensation’s a tad odd at first, but past short accommodation phase my ears got nothing short of joy out of it.On refinement and overall completeness, the German machine had its sonics dressed in a suit sharp enough to score as many points as the AMP-13R did. If I were driven exclusively by these criteria and forced to pick just one of the two, I’d be truly torn apart. However, the former’s power output wasn’t sufficient enough to land the effect as easygoing and fully developed in the lowest octaves as this report’s other heavyweight products, let alone the Bakoon. Yes, in case of minimalist recordings with say two string instruments and one vocal line, the smallest integrated had to make some room on the podium for the DFP. But a substantial chunk of my daily music intake includes artificially generated downstairs slams, that’s my guilty pleasure. With such repertoire I could push the German’s volume knob all the way up at times, yet the appetite for more was still there, which didn’t happen with any other product in this report. I look forward to the day when Reinhard Thöress decides to make a headphone amp capable of driving anything out there on the market. He might.The Pro iCAN subject wasn’t exactly straightforward and abundance of options this multi tasker provides was the reason. It’s fair to label iFi audio’s TOTL headfi deck as a chameleon type of a product, which doesn’t sport just one universal sound profile. Once set as a sole transistor, this machine approached the EX-M1 and AMP-13R on speed, crack and soundstage size, but wasn’t quite as nimble, untamed and complex as these two. It didn’t move as much air and wasn’t as liberated, but sported mild tension. Figuratively speaking, the Pro iCAN shifted all its gears capably enough to drive Susvara to the destination place without bumps along the road, but did so not as swiftly and fluently as its opponents.The Pro iCAN’s valves fully engaged (the Tube+ mode) extracted its inner expressiveness potently enough to land overall voicing somewhere in the ballpark of the DFP. But again, on evenly dosed harmonic content, articulation and background silence, the former wasn’t quite there. It reached very high given its ask, but not this high. Still, all battles listed here are of minor relevance in the grand scheme of things. The Pro iCAN’s compliance with Susvara is factual, this versatile amp drives this notorious load even in spite of lesser fit with it versus other devices. But shifts from any of these to iFi’s top shelf headfi deck invoked no pain, none was able to render today’s jack of all trades as inferior and that’s the key takeaway. I honestly couldn’t complain with it set in the Tube+ mode and fed from my quick and resolving Pacific DAC. Many seasoned headphone veterans would be surprised how well this setup sounded.


Today’s rather specific subject had sound quality set as top priority, which is why neither I cared about price tags of involved components, nor their size, topology or primary functionalities. I’ve decided to use every measure viewed as feasible for HifiMan Susvara and I’m happy I did. The idea of say a line stage or muscular class AB amp on the job with these headphones might seem debatable, if not unreasonable and/or plainly sketchy, but past all conducted triangulations I beg to differ to quite an extent.

Big, heavy and hot 100wpc+ amps are the ticket for compliance with Susvara, but not necessarily the golden one. Although the correlation between this product’s bass potency and power output was clear, it wasn’t quite as important as many people would think. This report’s notorious load didn’t care about stout power feed as much as it enjoyed its quality, that’s the fundamental lesson for today.

Of all devices used, only the Thöress DFP fell short on sheer drive with Susvara, which was not that surprising considering what this preamplifier’s circuit also tailored for headphones really is. Even though iFi audio Pro iCAN (14wpc into 16Ω) positioned itself below all other devices on sonics, this versatile all-rounder is fit for Susvara and every other planar/dynamic/IEM product on the market as well. Individuals in possession of multiple cans and this report’s specimen as one of them, should at least investigate iFi audio’s machine. That’s my sincere advice. Let’s draw the line here and move to the big guns.

Kinki Studio EX-M1 (215wpc/8Ω, full transistor, class AB) emerged as a gem of an amp for speakers months ago, and now as a fabulous companion for HifiMan’s planar top dog. I’ve found this combo as impressive as it was synergistic. Highly. If I hadn’t had mapped performance of the remaining two devices with Susvara, the EX-M1 on the job with this model would be my very easy top pick. If you’re short on cash, Kinki Studio’s integrated stands out as a great bang-for-buck match for it with no strings attached.

Although it seems silly to pursue Trilogy 925 (135wpc/8Ω, valve-transistor hybrid, class AB with class A envelope up to 10wpc) to handle Susvara, these two products’ performance surpassed my early expectations by the proverbial country mile. The effect of their effort rang my privy bells in just the right way and was entertaining enough for the 925 to secure the second place on the podium.

I had multiple reasons to award the Bakoon AMP-13R (25wpc/8Ω, a current-driven class AB power amp with lightning-fast true variable gain) with our ‘Victor’ badge one year ago, but today this petite deck pushed me towards stretching the red mark for it as a can amp. I’ll need to investigate it with other headphones and regular competitors to know more, which is a story for another time. What’s relevant now is performance the AMP-13R and Susvara delivered as a package. To my ears it’s the closest to sonic perfection to date. Neither I’ve heard a headfi team more exquisite, emotionally loaded, involving, alive, complete and balanced all at once, nor I think I will anytime soon. ‘Works awesome’ indeed…

Associated Equipment:

Retail prices of listed components in EU (incl. tax):

  • HiFiMan Susvara: €6’000
  • Bakoon AMP-13R: €6’000
  • iFi audio Pro iCAN: €1’999
  • Kinki Studio EX-M1: €1’840
  • Thöress DFP: €9’900
  • Trilogy 925: €13’999