Current testing methodology is v1.2
September 8, 2022
$35.00
1.76 oz
4.13 x 2.95 x 1.34 in
The 7HZ Sevenhertz 71 is a headphone amplifier digital-to-analog (DAC) dongle made by the same company behind the highly acclaimed 7Hz Timeless, Salnotes Dioko, and Zero.
With predominant releases being earphones, you could say that it’s the brand’s first foray into the dongle scene.
Interestingly, the Sevenhertz 71 uses the same AK4377 chip found in the venerable Lotoo Paw S1, which costs five times more even in today’s arena of highly efficient dongles.
Will the 7Hz Sevenhertz 71 impress? Let’s find out!
7Hz Sevenhertz 71
A DAC dongle that can power up almost any IEM.
Image Gallery
Click to view gallery
TL:DR;
The 7Hz Sevenhertz 71 is a warm neutral DAC dongle that employs the musical and smooth AKM signature.
It has a slight boost on the low end, warm neutral mids, and an extended treble that’s resolving as it’s sweetly done. What you feed it is what you get, but it generally maintains the original nature of a song with just a little more engaging low-end and a smooth presentation throughout.
Technicality-wise, it can perform a lot of fundamentals equally well, making for a very competent and well-rounded skill set. With its signature paired with solid technical ability, it places itself in a good spot in the budget realm of affordable quality dongles.
For the budding audio enthusiast, I don’t see why it wouldn’t be a good idea to get a taste of the classic AKM signature after having tried a couple of ESS Sabre chips. The 7Hz Sevenhertz 71 won’t disappoint.
The Specs
- DAC Chip: AK4377
- THD+N: -108dB/0.0004%@32 ohms
- Output Power: 70 mW@32 ohms
- Output Voltage: 1 Virms@32 ohms
- Sensitivity: 106 dB
- Frequency Range: 20Hz – 40kHz
- Noise: <0.9 μV
What’s in the Box?
- 7Hz Sevenhertz 71 Dongle
- User manual
Stuff I like
- Slight low-end emphasis
- Smooth note presentation and natural soundstage dispersal
- Good resolving power
- Drives low impedance IEMs really well
- Minimal power usage which helps preserve battery life
Stuff I like less
- LED light can be too bright, probably needs diffusion
Where to get it
Comparable products to consider
At $45, the Shanling UA1 is a highly compact and portable DAC from the Shanling Digital Techno.
First Impressions
The 7Hz Sevenhertz 71 on my first testing went well without a hitch.
I found that it can juice up my earphones with little to no effort – and quite loudly for that matter. I just snap the volume to about 4% and my in-ears are driven fully.
They’re advertised to perform at 1vrms or 70mw/32ohm load, so initially I was thinking they had less driving power than my Shanling UA1. Curiously enough, the Sevenhertz 71 didn’t need as much volume gain as the Shanling UA1 did.
Using the same songs, I’d go with as much as 40% with the UA1 while the 7hz Sevenhertz 71 only needed about 4% or 7%.
Thermals were also better with almost little to no warming on its shell even after long use. The UA1 can get quite toasty after a while so I guess another point goes to the praise of the Sevenhertz 71.
And while it’s only much later that I’ve been able to describe in detail the sound signature of the Sevenhertz 71, I found it to be analog-sounding with a good touch of warmth. Compared to the UA1, it does sound a little heftier in its delivery of note weight.
Although it stays neutral, I can’t help but notice that it’s more suited for warm-sounding IEMs than more neutrally-tuned ones. The body it gives probably makes warm-sounding IEMs sound thicker and lusher.
In terms of amplification, it can handle all my single DD in-ears with ease. I tried my hybrids, and they were driven with ease as well. My planar headphones managed to get driven to about 80% of the way and while the 71 does perform quite admirably, I don’t think it’s made to drive planar sets.
Build Quality
The 7Hz Sevenhertz 71 is a chic-looking dongle. It’s black and mostly matte but weirdly becomes glossy towards its USB C termination.
I appreciate uniformity and parallelism in design and while I do praise bold and outlandish style choices, it would’ve been better if they made the build matte all over.
The Sevenhertz 71 is the epitome of compact and solid. Its rigidity is amazing, and I don’t think a lot of hissy fit throws are going to put a dent in it – although I wouldn’t recommend you vent on a dongle.
The build is robust and very likable although I’m somewhat itching to paint the termination a matte black just to satisfy my OCD tendencies.
Sound Signature
The 7hz 71 sounds mostly analog.
It took quite some time before I can sort out its difference from my other dongles but I think it’s because it remains mostly neutral, making me slightly short-circuit in trying to find the thing that’s readily apparent.
The bass has a noticeable boost that gives punch to the low end. I find it gives extra girth and meat to bass notes, making the bass guitar all the more enjoyable.
The best thing about the low end is that it doesn’t sound like an iFi Hip DAC’s X-bass. It’s natural and doesn’t overwhelm the senses.
The mids, for the most part, sound very neutral. I think you’d have a higher chance of getting a colored sound with the IEM or headphones you’re using than with the Sevenhertz 71.
What you feed it is what you get.
While being modestly good at neutrality, it isn’t as analog as the VE Megatron, which at times can sound stale. The notes are full and have a good glaze of warmth to their articulation.
As for the treble, the 7hz Sevenhertz 71 sounds pretty extended without any grainy peaks and dips. Since it uses an AKM chip, the treble, albeit with its good extension, will have a wetter sound to it compared to something that uses an ESS Sabre chip.
This means that transients will sound moist and more rounded on the edges rather than dry and sharp. The keyword here is smooth. And while some prefer the analytical nature of ESS Sabre chips, AKM is all about smoothness and musicality – which is very hard not to like.
Technicalities
The 7hz Sevenhertz 71 has a pretty good overall signature.
Realistically though, what got me to keep it among my growing dongle collection was its matching technical ability. Its amplification is excellent, being able to power all the IEMs I tested on it with ease.
I tried juicing up my planar HE400SE on it and it performed admirably with just a couple of notches of volume left to go in terms of being fully driven.
Other technicalities are also competent performers with sound separation and transient response being two good attributes immediately after staging, layering, and imaging.
The soundstage is depicted with good space in its reproduction of width, depth, and height. While it’s by no means the cavernous levels a desktop setup can produce, it succeeds in being spacious and natural in delivery.
The layering is done smoothly – it cleanly merges the registers and instruments without losing fidelity or sounding congested.
The imaging lets you place instruments within the soundscape with ease. Again, while not a TOTL pin-point accuracy type of experience, it lets you enjoy music with accurate instrument positioning.
The sound separation is done well with thresholds placed cleanly within their boundaries, making vocals, instruments, and percussions distinct and able to perform on separate planes.
The transient response is swift in its attack and decay with a smoother presentation that still manages to be dynamic and engaging.
Conclusion
Out of the box, the 7Hz Sevenhert 71 was pretty modest being the sole contents of the box along with a user manual.
Like all portable dongles though, the real contents are what’s inside the dongle itself, and what it has is a whole lot of awesome.
With the boosted low-end, the warm neutral mids, and the smooth treble – seriously, what’s not to like?
Although I would’ve liked a balanced termination, that would change the dimensions and perhaps the internal circuitry to accommodate for more power. Naturally, this would also affect the thermals, which the Sevenhertz 71 does an excellent job at keeping very low.
I do think it has plenty of power – it’s just that I like having more options when it comes to outs. In any case, the 7hz 71 doesn’t do anything wrong here.
Factoring build quality, signature, and technical chops into the price, I think the price is very well-placed at $35. I
love how someone can get a taste of the AKM signature for a change, considering AKM dongles are lone fishing boats in a sea of otherwise ubiquitous ESS Sabre chips.
If by some chance you’re looking to pair your warm IEMs with a glossy analog source that keeps things groovy and lush, I think the 7hz Sevenhertz 71 is a great choice.
Smooth is the name of the game and you’ve been hit by a smooth criminal.
Gavin is a college student who has a lot going on. From collecting IEMs and modding mechanical keyboards, to different hobbies like digital drawing, music mastering and cooking. It is safe to say he is a complete multi-faceted geek (and he's kinda cool too)
This post was last updated on 2023-11-28 / Some images from Amazon Product API & some links may be affiliate links which may earn us a commission from purchases.