Astrotec AM850 MK2 Review: Modern classic

Astrotec AM850 MK2 Review: Modern classic

Astrotec is one of the OG Chi-Fi brands that are persevering despite the overwhelming inflow of new brands. Despite their popularity in the old days, the brand had some time when its recognition faded away from the mainstream hype. Yet since last year, Astrotec has been taking a thorough revamp for their line-ups and gradually returning back to their past glory.


Today we’ll be talking about AM850 MK2, the new successor of the AM850. To whom may have not known, the AM850 was one of the iconic IEMs that were brought up when talking about Chi-Fi earphones. That was back in 2017, which is close to 5-6 years until the next generation is released. That’s quite a long term, particularly among the Chi-Fi market. The original AM850 still leaves me with a pleasant memory to this day. Now that Astrotec is showing better form with their products, my expectations with the AM850 MK2 are quite high. Let’s now begin the review and see how the long-awaited classic performs.




The AM850 MK2 comes with a black, pleasantly simple package. Close-up earpiece rendering at the front and brief spec info at the back. Once unboxed a pamphlet is shown with the including sitting under it. Below is the list of accessories included with the MK2:

  • Earpieces / 3.5mm stock cable
  • A leather storage case
  • 1 pair of earpiece sleeves
  • 3 pairs of tuning nozzles
  • 6 pairs of silicone tips / 2 pairs of foam tips
  • A cleaning tool / a velcro tie / some paperwork


The AM850 MK2 comes with a flawless amount and variety of accessories to accompany both the listening and user experience of the IEM. Alongside, the silicone eartips come in two different types (3 pairs each), one having colored cores and the other being plain white.


The eartips with colored nozzles are very elastic and smooth that adhere better to the ears. The other one is slightly denser in texture but still soft enough. Each type provides a different fitting and acoustic experience which adds diversity and options for preference. The included case feels nice to the touch and the magnet clamps close the case tight. The size of the case is compact but enough to store the earphone. On the inside, there is a mesh sleeve to store a few small accessories.



Earpieces – Specs and features

The design of the earpieces is artfully and pleasantly simple. Using CNC metal chassis, the AM850 MK2 is designed ergonomically that slugs in nicely to the ears without any edge that would bother the ear canal. The housing has a grey color and an iconic logo on the faceplate. The nozzle diameter is about T400-T500 and uses standard MMCX termination for the cable.

Perhaps the MK2 is the first Astrotec IEM (if not after a long time) to be equipped with interchangeable nozzles. Three types of nozzles are included, each being called Neutral, Tide, and Air. Each nozzle type has a different sound signature (노즐 소리 성향)


Summary of the driver configuration is as the following:    

  • Single dynamic driver / 10mm LCP diaphragm
  • Input: 1 mW
  • Impedance: 32 OHM
  • Max Input: 3mW
  • Sensitivity: 106dB/1mw (S.P.L at 1KHz)
  • Frequency Response: 5Hz – 35KHz


As the predecessor, the MK2 uses a single dynamic driver but with several noticeable differences in structure and execution. Astrotec introduces that the AM850 MK2 uses a new generation 10mm LCP diaphragm with quality components from Japan. Astrotec has also incorporated a delicate feature to play a major role in tuning the sound.

Called the “SQUAMA Damper Balance System”, the fine grain and patterns are etched inside the chassis, effectively reducing unwanted resonance. This contributes to offering cleaner mid-range, higher accuracy trebles, and neutral/wider soundstage.



The Stock Cable

The included cable is quite decent. It’s made of silver-plated, high-purity OFC cable with a 3.5mm plug. The cable is light in weight and soft which that doesn’t cause microphonics. It’s a 4-core braiding with a multi-strand design on the inside. The connectors and Y-split are made of metal, overall giving a sturdy feel. It would’ve been better to offer interchangeable connectors as some budget IEMs began to incorporate them as well. Of course, that could still be asking too much for its price. The MMCX connection is firm enough that the earpieces do not spin around too easily.



Sound impressions – The Lows

As a dynamic driver IEM, the AM850 MK2 does its duty for the bass response. Lows are thick and plentiful with a slightly v-shaped quantity. To be a bit more specific with the quantity, the quantity is significantly stronger flat, and mildly lesser than full-on basshead IEMs. If you’re looking for a generous amount of bass, the quantity should be sufficient.


The AM850 MK2 also has great density and tightness but is closer to a soothing type than the rigid, stiff density. Reverbs are generously highlighted but not exaggerated nor loosen density. If you’re looking for a strict density that the bass smacks as a rock with minimal reverbs, this one may not be ideal for your taste. However, great bass elasticity and warmness are brought into the AM850 MK2 while not degrading the clarity and timbre. The bass speed is average, not particularly agile but not falling behind either. It overall has quality depth and ultra-low retrieval that allows a nice headroom space.



Sound impressions – The Mids / Soundstage

Mids are mildly placed forward and make a very natural, seamless transition from the bass. The vocal timbre is also very neutral and warm, just like the original AM850. As lows and mids are similar in temperature along with the seamless transition, the division between these two isn’t cut-edge separated. The AM850 MK2 works the bass and vocals to play it out in harmony, making the music just flow – while not causing these two frequencies to be cluttered or bland. Of course, if you’re looking for balanced armature-like agility and technicality, this sound signature may not be ideal.


The mild shininess and air can be found from the upper mids which prevent the vocal to get stuffy or overly warm. Sibilance is also nicely controlled, not causing any timbre distortion or turbulence across the range. Vocals are well-bodied with appropriate thickness, approaching with good size and fullness. The soundstage is pretty large. Grand depth and scale from the bass play a major role in the headroom, along with mids and highs showing good size and 3D imaging.



Three tuning options

Different nozzles offered a noticeable difference in the sound signature of AM850 MK2.

Air (Gold nozzle): Highs get a tad clearer along with a bit extra transparency and shine on the vocals. The upper ends sure get vivid and agile. The bass quantity does not change much. However, the fullness from lows and mids would slightly decrease. It’s an ideal choice for those who seek more resolving mids and trebles.     

Tide (Grey nozzle): This is my personal favorite. This filter just sounds the most natural in terms of bringing out the max of AM850 MK2’s intended tuning. It brings out vivid bass response along with clear yet fatigue-free trebles. The Tide filter will be the default choice for this review.    

Neutral (Black nozzle): This one adds a bit more body and thickness to the mid-range, along with a glimpse of extra warmness. It’s an ideal option for those who seek to add thickness and density to the mids. The bass also gets a bit tighter and calmer with gently reduced reverbs. Other than this, the Neutral filter sounds almost identical to the Tide filter.   


Sound impressions – The Highs

While soothing warmness is a core characteristic of AM850 MK2, highs take a bit of a turn in style. Highs are agile with stronger analyticity, nicely revealing texture strands and details. Brightness is also noticeably enough brighter. These are all of course done without altering the core characteristics of how a dynamic driver would sound, so highs do not sound unnatural or in disharmony with the other frequencies. The crisps are there with clarity but it doesn’t overpower the music.


I’m pleased with the treble of AM850 MK2. Most single dynamic earphones in this price range with a bassy sound signature commonly manage to do decent with lows and mids, yet trebles always came to be a challenge. Some often had strong bass with suffocating mid and bright but unnatural treble. The other rest would have good bass but with the upper range done poorly in general. Astrotec managed to tune AM850 MK2 to have BA-level details but with crisps and timbre that matches seamlessly with the IEM’s strong dynamic driver nature. As a result, highs are well-distinguished while nicely blending into the music and with just an appropriate amount.                 



Compared to See Audio Yume

AM850 MK2 is warmer in timbre and a bit dimmer in brightness. It has a stronger bass quantity and smoother texture, overall showing a larger, fuller, and deeper bass response than Yume. On the other hand, Yume’s bass sacrifices some softness/smoothness in exchange for retrieving clearer grains of texture. Technicality is highlighted more on Yume whereas AM850 MK2 is more into dynamics and musicality.


As for the upper range, Yume has a brighter and airier presentation that highlights more clarity. The temperature is also a bit colder – but only relatively, not objectively. Mids are thicker and fuller on AM850 MK2, as well as the vocals sound more creamy. While both IEMs desire good balance, choosing between these IEMs would come down to determining if you prefer warm, lows-mids oriented sound or neutral bright, strict balance-oriented sound; the former being AM850 MK2 and the latter being Yume.



Compared to IKKO Obsidian (OH10)

The OH10 is a well-made IEM that differs in sound signature in several ways. First, the bass achieves a good extension as the AM850 MK2, yet with less body and reverbs, offering a more linear response. Since the bass quantity is lesser while achieving depth, clarity is superior to AM850 MK2 but lesser in fullness. The OH10 also has a marbly, brighter upper range that highlights stronger quantities than the AM850 MK2, which tips towards being neutral-bright. This may be rather bright for those who seek a smoother, warmer-sounding IEM while clarity seekers would find it more pleasing than the AM850 MK2.


Another significant difference is that the ups and downs of the music, or the contrasts of low-end and high-end, are very distinctive on the OH10, giving more of a rollercoaster experience in dynamics. Meanwhile, AM850 MK2 seeks a universal style that keeps stability and coherency in timbre. The OH10 may sound more fun but is also more prone to being fatigued or sounding “exaggerated” than the AM850 MK2.      




The AM850 MK2 took a similar path as the Dita Perpetua in terms of going for warmth and bass-oriented sound, as well as vividly expressing its own style of music. What’s the point of having diversity if all of them are going to sound similar in style? Although this is not a type of sound that those who seek sounds that aggressively focus on details like recent IEMs do, yet the MK2’s firm sound identity nicely follows up with the beloved analog sound of AM850.


Giving a gear with a Chi-Fi tag usually implies a cost-effective impression – the performance being just about decent considering the price of it. However, I believe the AM850 MK2 does not deserve to be stuck in such a boundary. Instead of just randomly seeking maximum cost-efficient, the AM850 MK2 is a well-made earphone that knows its tuning concept and style, and I’ve found this uniquely warm sound signature to be appealing. If you’re into a fatigue-free, classic dynamic driver sound but also don’t want that typical, boring bassy sound, the AM850 MK2 would be one of a kind. As a side note, I’ll just say I enjoy this earphone even among the flagships I own.        



Player: Questyle QP2R

Eartips: Stock tips / Tide Nozzle Filter



Tribrid Flagship (2nd gen): Astrotec Phoenix 6

Tribrid Flagship (1st gen): Astrotec Phoenix    

Mid-range 1DD: Astrotec Volans

Mid-range 5BA: Astrotec Delphinus 5    

Have thoughts or questions? Leave a comment below!

Astrotec AM850 MK2
Bass-oriented but charismatic sound
Warm and full while having crisp enough details
Great comfort
Nozzle tuning feature
Ideal for those who seek classic/analog tuning but with fun
Not ideal for those who seek aggressively resolving details
Not meant for those who seek flat/linear sound signature
The difference brought by nozzle tuning isn't too significant