PlusSound Allegro

The tempo of PlusSound next movement!

PROS: balanced sound tuning with a clear detailed tonality, powerful DD bass response, vivid sound presentation, big soundstage, beautiful all metal shell design, premium cable, and accessories.

CONS: price, the fit.

The product was provided to me free of charge for the review purpose in exchange for my honest opinion.

Manufacturer/product website:  PlusSound.


2022 was a busy year for Christian and his PlusSound Audio company, celebrating 10-year anniversary with releases of new “+” series cables.  But apparently, he saved the best for last, literally before the end of the year making a big announcement about their flagship IEM.  It’s no longer shocking to see a cable or a DAP company release IEMs, and PlusSound already dipped their toes in the water back in 2017 with a set of budget-friendly IEMs, Spectrum, Prism, and Gamut.  What made this announcement more of an unexpected surprise was PlusSound stepping up with a release of a multi-kilobuck flagship, Allegro, entering a market already filled with a stiff competition among other established IEM brands.

It was definitely a bold move because this is no just about throwing together a handful of drivers that look good on paper, but actually having to tune it to be worthy of a flagship status and a price tag.  After the announcement, the first production run was offered in 3 limited editions, 10 units of Special Edition that included Hybrid+ cable, leather earphone stand, and TWS-C wireless adapter, 25 units of Limited Edition with Hybrid+ cable, and Launch Edition with Copper+ cable.  Special and Limited edition were sold out pretty fast, while low quantity of Launch Edition is still available.  I spent the last few weeks listening to Allegro which I received for review along with Special Edition add-ons, and now ready to share what I found.

Unboxing and Accessories.

The product I received for review arrived in two small boxes.  One was a retail packaging of their Leather Stand, and another one had Allegro, TWS-C cable with a charging usb-c cable, and other accessories.  I have reviewed Copper+, Hybrid+, and Silver+ already, so there was no need for another set of cables or leather cable band organizer.  And the same with a leather storage case, since I reviewed it already and there was no need for another one.  Everything I received was included as part of Special Edition package, and Leather Stand and TWS-C cable can be purchased by itself directly from PS.  A leather storage pouch, cleaning microfiber cloth, cleaning tool, and round sticker were included as part of additional accessories.  Plus, you get 3 sets of eartips in S/M/L sizes, one was a set of brand name Symbio W hybrid eartips, another was a set of Comply foam eartips, and also a set of PlusSound own silicone eartips which you can buy from them separately.

The design of the leather storage case is very straight forward.  It’s a rectangular case with a heavy-duty gold-plated metal zipper and exterior dimensions of approximately 5” x 6” x 2” and internal storage space of about 3.75″ x 5.5″ x 1.75″.  The exterior material is a real genuine high-quality leather with a stamped PS logo on the top cover.  The case is available in 3 leather finishes which you can purchase separately.  The one I received was brown.  Inside, the case is lined with a soft felt material to keep everything protected and scratch free.  Under the cover you have a large polyester pocket, a bit tight, though with enough room to store microSD cards, cleaning cloth and a cleaning tool.

Inside the case there is an insert, lined with the same felt material.  Instead of having adjustable or fixed partitions, the insert features 2 semi-enclosed corner pockets for either IEMs or CIEMs.  The pockets have plenty of room even for large custom shells, and allow for the cable to remain attached while letting it extend down to wrap around the organizer wheel/spool below it.  There is more than enough room for a thicker 8wire cable and a large 4.4mm connector, keeping it away from the shells.  As an optional accessory, PS also offers a Leather Stand based on the design of the insert, but made out of leather, the same premium material as the case.  The stand features a cutout for IEM nozzles and a kickstand to use it standalone without a case.

As already mentioned, arrived with my review sample was PlusSound new TWS-C Bluetooth wireless cable with 2pin connectors.  It was included with Special Edition package and can be purchased directly from PS.  While it does carry “TWS” name, it is not exactly a true-wireless-stereo adapter but rather a true-wireless cable which has a bonus functionality of USB DAC.  Yes, you can charge it with included usb-c cable (no need to deal with micro-USB like some other adapters), and you can also connect it with usb cable to your laptop which turns TWS-C into USB DAC.  Its wired control unit is designed to be worn like a pendant with attached left/right cables and PS signature style chin slider and 2pin connectors.  The TWS-C I received had Hybrid+ cable wires, but when purchased separately you can pick and choose from a selection of other PS wires.

It does support most of the Bluetooth codecs, except for LDAC.  And, in addition to USB DAC functionality, it also packs other features, like 7-preset EQ which you can activate by pressing all 3 buttons at the same time.  Everything is controlled through these 3 buttons to Play/Pause ‘O’ in the middle (single click), to skip next/prev using + and – (double click either one), fast forward/back (press’n’hold +/-) and change the volume (single click +/-).  You will also need to press both +/- to remove all pairing and to enter the pair up mode.  I have tested TWS-C with my phone and many different DAPs.  The only thing I found in pair up with my Galaxy S22 was while changing the volume it also fast-forwards/back in 2sec increments.  Surprisingly, it only happens with my S22 and no other DAP I tried.  Otherwise, it’s a solid performing adapter that turns your IEMs into wireless.


PlusSound Allegro has a tribrid design with 12 drivers per side, featuring 2x 10mm DD drivers (covering sub-lows and lows), 6x BA drivers (covering lower mids, mids, and upper mids), and 4x EST drivers (covering highs and super-highs).  The drivers are partitioned across 6-way crossover network and arranged inside of the 3D printed acoustic chamber.  Exterior design is beautifully crafted and features polished, anodized, and cryogenically treated aluminum faceplate with a copper finish, multi-faceted inner side of the shell in black finish, and a short wider nozzle with a lip (to secure eartips) and 3 bores at the tip.

I looked closely but didn’t find any separate pin-hole vents.  But there was one long slit-vent on the back, most likely for DD drivers, and still a decent sound isolation and no driver flex.  Also, 2pin socket is partially recessed, but not all the way down to hide the 2pin cable connector.  According to PS, the 2pin connector is their own in-house designed cryogenically treated 0.78mm rhodium plated with PEEK insulation.  The internal wiring is also custom, their own in-house designed cryogenically treated Type 6 UP-OCC wires with proprietary insulation.  Based on all these PlusSound customizations, it is clear to me that we are not dealing with some blindly rebranded design.

Of course, all that above is just a description of building blocks, inside-out, which must add up to a sound tuning that going to resonate with audiophiles, something I will talk in more details in Sound Analysis section of the review.  Aesthetics and durability of the design are very important factors as well, which brings me to a topic of the fit.  Sound tuning is up to a personal preference while the fit is up to your individual ear anatomy.  In my opinion, the combination of a bulbous shape of inner side of the shell and a short nozzle could be a problem for some ears.  It took me a little while to find the right set of eartips in order to extend the shell a little bit further out of my ears, thus I advise to spend extra time and go through all the included and your own eartips to achieve the comfortable fit.

The fit (uni).



Since different editions of Allegro feature different versions of their “+” series cables, I’m sure you can contact PlusSound while placing the order to request a specific one you want to be included.  These new “+” cables are not your typical Type 6 litz wires that feature bundles of twisted wire strands.  Here, in addition to multiple twisted litz bundles, there is also a secondary twisted litz wire bundle used as the core with a more durable dampener to support outer wires.  Also, each strand still has enamel coating to prevent oxidation and crosstalk.


In order to keep the overall wire size of the new cable close to other PlusSound cables, a new unique shielding using a silver layer between the insulation and wires was implemented.  This new shielding is two-sided and in addition to protecting the wires from outside interference to eliminate EMI, could also serve as a ground.  And the secondary silver wire at the core could be either grounded or conduct a signal separate from the litz bundles around it.  In a way, the cable has a coax-like structure with two wires in one, allowing more design flexibility.

As a result of the updated design, the wire is approximately 15% larger in size and a little stiffer in comparison to a standard Type 6 litz.  Furthermore, these new “+” cables are available in Exo series (4wires), and feature a rhodium plated 2pin, rhodium plated 4.4mm, and new outer insulation, as well as PS signature design y-split and chin slider.

Page 2 – Sound analysis and Eartips selection.
Page 3 – Cable pair up and Source Pair up.
Page 4 – Comparison and Conclusion.


One thought on “PlusSound Allegro

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