Powerful bass performance, High midrange coherence and structure, Immaculate background, Well-detailed treble, Very wide soundstage, Robust build quality
Somewhat stiff wires, Separation takes a hit, Midrange can sound too roomy on some pairings
The Copper+ is a complex and well-realised take on a copper custom cable defined by an especially wide stage, immaculate background and robust, powerful bass.
If you’re reading this review, you’ve likely come across Plussound in some manifestation. The American custom-cable maker has been hand crafting for close to a decade now and have built up a legendary reputation. The development process of any custom cable is highly empirical, thereby, requiring prodigious amounts of time to tune and perfect. As the industry’s understanding of cable design evolved, so too did the approach to design evolve. Where previously custom cables mostly entailed exotic conductors, recently we’ve seen geometry play a much larger role with a simplification of the conductor setup providing a more focused package. Christian has been hard at work developing his entry into the new trend seeking to maximize the capabilities of simple Copper. Welcome the Copper+, the company’s new exclusively copper-based flagship cable.
The Copper+ starts from $1025 USD with pricing depending on termination and cable design. You can configure one to your preferences on Plussound’s website.
I would like to thank Christian from Plussound very much for his quick communication and for providing me with the Copper+ Apollonian for the purpose of review. All words are my own and there is no monetary incentive for a positive review. Despite receiving the cable free of cost, I will attempt to be as objective as possible in my evaluation.
Behind the Design –
Using copper conductors exclusively, the quality of that material characterizes the cable. Plussound is using high-purity OP-OCC copper in a larger 24AWG thickness. This plays a larger role here due to the skin effect whereby current prefers to travel through only the exterior of the conductor. This is due to the generation of eddy currents by the alternating current produced by the source in the centre of the conductor, resulting in reduced transmission efficiency in these areas. In turn, a larger gauge represents a much larger decrease in resistance than the small jump in size may suggest due to the proportionally larger surface area available for conduction.
Christian didn’t stop there, a statement product should do just that. He’s chosen to differentiate his design using a trick new geometry that mimics having two cables in one. Where even the highest Litz configurations, considered to be industry leading, use a damping central core, the Copper+ instead has a single-twist Litz core comprised of conductors. A layer of 5-strand bundles also in a Litz configuration surround this core as you would see on a regular Type 6 Litz cable.
Shielding always plays a substantial role in cable design, some would say it is the most important component. Chris has addressed this too with a brand-new type of shielding dubbed PS Shielding which lies just beneath the outer most jacket and works in tandem with its braided construction. It is made from dense silver and has the ability to function as a ground layer as we’ve seen on some other custom cables. The company’s signature PS insulation makes a return, once again one of my personal favourites, being ultra-supple and resistant to hardening over time.
I’m a huge fan of the new unboxing which we first saw on the PPH. The buyer receives a small hard box with a premium satin black finish and gold debossed Plussound logos. Opening the top lid reveals an acrylic top lid and just below, the cable within a lovely leather Plussound pouch. The cable also comes with a premium leather button-clasp organizer strap and a microfibre cloth to keep the connectors gleaming. It provides a premium unboxing experience alongside a thoughtful selection of accessories.
I admire that Christian is always revisiting his designs; I wasn’t initially a fan of Plussound at all around their inception, but his new cables are easily among the best I’ve used. As of 2020, Plussound has started using metal connectors on all of their models. These are gorgeous metal parts with chamfered edges and customizable colour inserts. Exposed grub screws on the plug and IEM connectors are charming reminders this is a hand-made product whilst avoiding ergonomic impact. I received the Copper + in Apollonian series which has standard insulation above the Y-split and tough fabric sleeving below giving it a premium, high-performance look.
I usually find Plussound cables to be ultra-soft and conforming. However, whether due to the densely packed conductors or its silver shielding, the Copper+ is noticeably stiffer. It’s not ethernet wire, but not as soft as your average cable either. The Apollonian setup also isn’t as conforming due to its thick sheathing below the Y-split, especially compared to the poetic or EXO series. It does feels incredibly sturdy and isn’t abrasive against the skin, nonetheless. While the cable remains highly tangle-resistant and coils easily for storage, there is some memory and additional microphonic noise on this model. Accordingly, I would suggest the 6 and 8-wire versions of this cable may be difficult to live with for IEMs.
On the 4-wire version tested here, stiffness wasn’t to the point that ergonomics become frustrating, it just wasn’t as excellent as on past Plussound cables. Otherwise, small touches here ensure a sound wearing experience overall. There are no ear guides, but a gentle fold in the insulation that routes the cable comfortably and stably over the ear. The connectors aren’t prone to bending and interfaced reliably with all of my IEMs. The overall fit and finish of the cable showcases the experience of the team at Plussound, easily being some of the best in the industry. That said, just don’t expect the same softness here, the Copper+ is stiff and a little microphonic.