Tour: Apos Audio – Topping D90SE DAC, Matrix Mini-i Pro 3, Apos Caspian Headphone, Moondrop Aria IEMs

A Treasure Trove of Audio Gear

October 2021

Apos Audio Gear Discussed in this Tour can be found here: https://apos.audio/ 

Apos Audio is an authorized retailer of new audiophile equipment from a growing but carefully curated set of brands as well as some of their own lines. As their first tour here on AudioTiers, they wanted to provide a broad selection of some of their most popular gear that will catch your attention. This assortment of gear ranges from DACs to NOON streamers to IEMs to their own Caspian headphone. This will enable you to use your own sources to hear the headphones as well as to try some new options.


While APOS Tour logistics will be discussed on this thread, please post your reviews to HEADFI and post impressions and links to your reviews on this HEADFI thread: https://www.head-fi.org/threads/apos-audio-audio-impressions-from-their-treasure-trove-of-audio-gear.961053/

Apos Audio Tour Kits

Given the size of the list, we have decided to break out the gear into two kits – a desktop kit and a portable kit. We also have full retail boxing for our tour. Below is a description of what you have in store for yourself as a tour member:

Apos Desktop Tour Kit 1:

  • Apos Caspian Open-Back Headphones ($499): Made with hand-assembled, sustainable materials, the Apos Caspian is an open-back headphone that looks timeless and sounds thrilling.
  • Apos Flow Headphone Cable ($149): Apos Flow Audio cables are made of 99.99997% pure single-crystal copper, ensuring an oxide-free, unobstructed signal.
  • Matrix mini-i Pro 3 ($1025): The Matrix Mini-i 3/Pro 3 is an all-in-one DAC/Amp that features MQA, Roon Readiness, and a beautiful full-color display.
  • TOPPING D90SE DAC ($899): The D90SE is the all-new (Summer 2021) digital-to-analog converter from TOPPING featuring a new ESS SABRE ES9038 PRO DAC chip and second-gen 16-core XMOS processor, with MQA now standard.
  • xDuoo TA-26 Tube Amplifier ($319): Go all-analog with the 500mW xDuoo TA-26 tube amplifier which goes minimal where other amps get fussy. 

Apos Portable Tour Kit 2:

  • Moondrop Aria IEMs ($80): The Moondrop Aria is a Liquid Crystal Polymer IEM with a metal-injected chassis, brass inner cavity, and a crowd-pleasing Harman Curve tuning.
  • Lime Ears Pneuma IEMs ($2160): The Pneuma is a five driver hybrid with a 7mm titanium dynamic driver for rumbling sub-bass, with four BA handling everything else from low-end punch to high-end sparkle.

Apos Audio Tour Kickoff Video

Tour Kit Pictures

Barra’s Quick Initial Impressions

The best part of managing tours is getting to hear all the great gear for myself. Here are some brief impressions from what I have heard so far between the tasks required to set up this tour:

  • Apos Caspian Open-Back Headphones ($499): This is my favorite item in the tour. There is a rich audiophile flavor with deep bass that is very seductive. The HP is light and comfortable while offering a good deal of isolation compared to other open competitors finding an optimal ratio. This headphone is great for both movies and audio listening finding an optimal spot at my desktop making my workdays fly.
  • Apos Flow Headphone Cable ($149): While I have not yet compared this balanced cable to the provided single-ended cable that comes with the HP, I have not found a reason to try anything else as it is a great match. It is well constructed and ergonomic feeling like it will last many years through any desktop rigors. 
  • Matrix mini-i Pro 3 ($1025): As a streamer that is ideal for Roon, I have not tested its full capabilities given I don’t have a Roon setup, but as a headphone amp, it works wonderfully. The key appeal for this unit is its bright-colored display that advertises your song and album art making it very fun. I Will wait to hear from some of our Roon experts during the tour.
  • TOPPING D90SE DAC ($899): This unit is impressive – a detail forward audiophile DAC with a large soundstage. In comparison to my other DACs, this one pushes forward gobs of detail that you may not hear/notice otherwise offering a new way to listen to your audio library. I really like this unit.
  • Moondrop Aria IEMs ($80): Having been spoiled for so long with constant access to the best of the best, it is hard for me to fairly judge this category, however, I have to say that I am surprised by what I experienced at this price point and it would be an easy recommendation for anyone looking in this price range. This is one that I know my wife would appreciate for look and feel, logistics of having a very nice non-tangling cable, and having the clarity and bass that she appreciates. While it will never compare to my customs priced in the thousands, I do have to admit that it is at least 80 percent of the way there for a lot of bang for the buck. 
  • xDuoo TA-26 Tube Amplifier ($319): TBD
  • Lime Ears Pneuma IEMs ($2160): TBD

Each of these tour items is impressive in its own way and will likely appeal to each participant in a different way. I am anxious to hear back from our participants to see their impressions.

Rules and Responsibilities

Most of our tours are offering 7-day auditions which you are required to ship out to the next participant on day 8. Yes, you pay the shipping to the next participant, but we organize into logistically friendly orders to minimize the shipping expense.

The tour membership rules and responsibilities are described here. The key idea is that we must be communicative to participate and to keep the tour moving and interesting. It is our responsibility to follow these rules and to ensure the ability to ship out on day 8 when our turn is over.

Signing up for the Tour

To sign up for the tour, you must be a verified tour member and have joined our new AUDIOTIERs platform. The membership qualifications and requirements are described here if you are not already a member. Whether a HEADFI tour member that needs to transfer their membership to the new platform or you are a new member looking to apply for tour membership, please follow the instructions in the GETTING STARTED box below. We are now accepting applications from both US and Canadian citizens.


NEW TOUR MEMBERS: 1) Register, 2) Subscribe, 3) Apply, 4) Join Tours

EXISTING HEADFI TOUR MEMBERS: 1) Register, 2) Subscribe, 3) Join Tours

Tour Signups for Verified Members: If you would like to be part of this tour, please feel free to post your request in the comments below.

Reviewers First Tour: This is a REVIEWERS GO FIRST TOUR, so if you would like to skip to the front of the line, please note that you would like to be a full reviewer in the request as in the sample below:

Sample Signup Request: I live in Anthem, AZ and would like to participate in the tour. I agree to follow the terms of the tour. I have emailed my required ID verification documentation to billb@AudioTiers.com. AS A FULL REVIEWER, PLEASE MOVE ME TO THE FRONT OF THE LINE.

Tour Participant Logistics

We are offering 7-days auditions to each participant. This logistics list is updated as I can to show you where we are in the order with each participant bolded to signify that they received the kit. This is where you will find the next two participants to contact when you receive the kit.

Signup Period: During our signup period, we collect the initial participants and provide them with a logistically friendly portion of the tour. This is the lowest cost portion in terms of shipping. Once this closes, we move to the latecomer portion.

Latecomer Period: Latecomers are welcome to the tour on a first-come, first-serve basis. We will continue taking latecomer requests until we run out of participants or the manufacturer asks us to end the tour.

Apos Audio US Tour Logistics

Lime Ears Pneuma plus Moon Drop Aria Tour Kit 1:

  1. Barra – Anthem, AZ
  2. REVIEWER: Jwilliamhurst – MO
  3. REVIEWER: ngoshawk – MO
  4. REVIEWER: darmanastartes – VA
  5. REVIEWER: Ike – KY

Apos Caspian with Flow Cable Tour Kit 2:

  1. Barra – Anthem, AZ
  2. REVIEWER: ngoshawk – MO
  3. REVIEWER: mochill – FL
  4. REVIEWER: jcslone – CA
  5. REVIEWER: antdroid – WA

Matrix Mini-i Pro 3 Tour Kit 3:

  1. Barra – Anthem, AZ
  2. REVIEWER: jcslone – CA
  3. REVIEWER: mochill – FL

Topping D90SE DAC Tour Kit 4:

  1. Barra – Anthem, AZ
  3. REVIEWER: jcslone – CA

xDuoo TA-26 Tube Amp Tour Kit 5:

  1. Barra – Anthem, AZ
  2. REVIEWER: Ike – KY
  3. REVIEWER: ngoshawk – MO
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US Tours
Reply to  Barra
01/25/2022 11:29 am

I don’t see my name listed for any of the tours, but I’ll request again and if you need any updated information for me PM me what you need and I’ll send a copy of it. I would like to audition the Topping DAC and the Matrix mini. I’m very interested in bluetooth streaming (both items) to me to listen to while I’m in bed and I’m looking at products like (the matrix) because I want to go all in to roon to organize my mess of flac albums.

Is this for reviewers only? If so, sorry I didn’t notice that stipulation. I see that everyone on the list is a reviewer so I’m going to guess that there’s a good chance it’s for reviewers only.

Last edited 6 months ago by hypermuteki
US Tours Reviewer
Reply to  Barra
03/06/2022 5:08 pm

I live in LA, CA and would like to participate in the tour for kit #2. I agree to follow the terms of the tour. I have emailed my required ID verification documentation to billb@AudioTiers.com. AS A FULL REVIEWER, PLEASE MOVE ME TO THE FRONT OF THE LINE.

US Tours
10/15/2021 7:10 pm

I live in Las Vegas, NV and would like to participate in this tour. I agree to follow the terms of the tour.

US Tours Reviewer
10/30/2021 1:40 am

I live in Warrensburg, MO ans I am interested in joining these tours. I agree to all terms and conditions of the tours as such. I am already confirmed. AS A FULL REVIEWER, PLEASE MOVE ME TO THE FRONT OF THE LINE.

US Tours
11/15/2021 11:49 pm

live in Porter Ranch, CA and would like to participate in the tour. I agree to follow the terms of the tour. All previously verified documentation remains current.

US Tours Reviewer
11/17/2021 4:38 am

Live in Lynnwood, WA. I am interested in joining this tour and verified reviewer. I am only interested in the APOS headphones and Matrix i3 Pro though, as I’ve owned or reviewed all the other items.

US Tours Reviewer
12/14/2021 10:45 pm

Hello. I live in platte City Missouri and I would like to review the lime ears pneuma, the matrix mini, the xduoo tube amp, the topping d90se in that order:)

US Tours Reviewer
12/14/2021 10:52 pm

I live in Honolulu, HI and I am interested in joining the Apos Portable Tour (Tour Kit 2). I agree to all terms and conditions of the tours as such. I am already confirmed. AS A FULL REVIEWER, PLEASE MOVE ME TO THE FRONT OF THE LINE.

US Tours Reviewer
01/20/2022 6:46 pm

I have received Kit 2, and sent the Caspian on to the next lucky participant.

US Tours Reviewer
07/07/2022 7:09 pm

Topping D90SE has been returned to Barra, and my impressions have been posted on Head-Fi and my blog.