Today we review one of PlusSound’s new flagship IEM, the PlusSound Allegro, which costs around $3,499 USD.
Disclaimer: PlusSound provided the Allegro free of charge for this review. PlusSound is not a site advertiser and is not affiliated with Headfonia.
PlusSound
PlusSound is an American company seated in Los Angeles that specialized in aftermarket cables but has also dipped its toes into the portable amplifier and IEM markets. 
PlusSound made its debut in early 2012 and has gained a lot of respect and interest for its outstanding products from the community. Ordering from PlusSound is pretty neat and easy. You can go to their website, select the type of cable you want and customize the materials, terminations and even the Y-splitter and chin-slider.
We have covered many different products by PlusSound in the past, and if you’re interested to learn more, follow this link.
PlusSound Allegro
PlusSound lately announced their new flagship IEM, the PlusSound Allegro. Although PlusSound is an aftermarket cable company in its heart, it’s nothing surprising for them to release a universal IEM. They’ve done that before with a handful of models and we even reviewed them in the past.
Allegro is a sophisticated universal IEM, as all the flagship tribrids have been so far. The Allegro contains two 10mm dynamic drivers, six balanced armature drivers, and four electrostatic drivers. The total driver count is 12, so that’s quite a configuration. These are all placed in a 3D-printed chamber inside.
Internal wiring of the Allegro is done by using PlusSound’s own Copper XS wires (Type 6 UP-OCC). The actual cable that comes with the Allegro is Copper+ with the launch edition, but you can choose another cable exclusively. Just contact PlusSound before ordering. Our sample comes with the Hybrid+, which is an excellent cable on its own.
Aside from the inside of the shells, the external design is also very impressive. The Allegro’s shells are made from aluminium, with a 7-axis CNC machinery. There’s a dark bronze polygonal faceplate and gloss black diamond pattern body on the inside.
Package and the Leather Case
The Allegro comes with the same packaging they use with delivering their new Exo cables. It arrives in a black and copper-coloured box. Inside, you’ll see a plexiglass window that informs you that the IEM was designed and handmade in LA, California.
Inside, you’ll see a brown PlusSound leather case, which I’ve mentioned in the Silver+ cable review. This case has wonderful quality and design, and you can get it separately from PlusSound, basically for whatever audiophile need of yours. The case is still on our Best Accessories page. This is genuine leather with a smooth surface and a great touching experience and great zipper quality. Inside is from soft material and you also have a wheel to wrap around your IEMs (removable). You have a polyester pocket to store SD cards, etc.
Under the soft storage compartment, you can find ear tips and a PS sticker. There are three types of tips here. Standard silicone tips, Comply foams, and Symbio W Hybrid tips. A good selection overall.
Build Quality and Design
The build of the Allegro, thanks to the full aluminium material and CNC process, is excellent. The best part of the design is that the aluminium is pretty sturdy and solid, but the IEM is lightweight. So you have a great build and lightweight shells combined. Overall a worthy design and build which is expected from the price.
Design is always a subjective topic, but I liked the new Allegro with a nice copper-coloured faceplate with sharp angles. That is coupled with great diamond-shaped inner shells. No doubt a very special and premium design from PlusSound.
Cable-wise, well, this is a cable company first and foremost. They use custom hardware for connectors and plugs, and in this case, the cable has fantastic quality. It is nicely braided with good consistency. The hardware, on the other hand, is incredibly good. My set came with black/silver accents with a 4.4 mm termination. The 2-pin connectors have to go with logos facing inwards, as the screws have to go out, contrary to many other manufacturers.
The 4.4m plug is the highlight of the cable to me, as it fits any 4.4 output snugly. The quality and the finish are excellent. Also, there’s no visible heat shrink from plastic or any other flexible material. Instead, the 2-pin connectors and the plug are finished with aluminium rings, so the cable looks very sharp and clean. The Y-split and chin slider on the cable is also silver-colour and the material is aluminium. Overall the cable is fantastic in terms of build and design. The black/grey colour may not be your cup of tea though.
Page 2: Fit, Sound
Page 3: Technical Performance, Comparisons
