Apos Opens Pre-Orders on the SJY ARGOS Electrostatic Headphones and Apos x ES Lab HYDRA Amplifier

Apos has opened pre-orders on a pair of electrostatic hi-fi products announced together on 18 August 2026: the SJY ARGOS electrostatic headphones and the Apos x ES Lab HYDRA integrated amplifier. The two are being sold as a matched pair built around the same 580V "Pro Bias" electrostatic interface, with both expected to ship on or before 15 October 2026, according to their listings on Apos's site.

The announcement, carried by The AI Journal, frames the launch as a return to electrostatic headphone listening drawing on what the press release calls the "golden age of Japanese hi-fi" — a reference to the lineage that began when STAX introduced its SR-1 electrostatic headphone in Japan in 1960. Beyond that historical nod, the release does not disclose who designs, owns, or manufactures either the SJY or ES Lab brands, and no independent measurements or reviews of either product exist yet.

SJY ARGOS: an electrostatic headphone at $1,800

According to its product page, the ARGOS carries a list price of $1,800, with a reduced pre-order price of $1,620 while the pre-order phase runs. Apos has not published an end date for that discount.

The headphone uses an electrostatic driver that Apos specifies at 6,375 sq mm, run on what the listing calls a "580V Pro Bias" supply — the standard high-voltage bias arrangement that electrostatic headphones require in place of a conventional amplifier. Other specifications from the product page include a stated capacitance of 130 pF measured with the included 1.5 m cable, a 5-pin Pro Bias electrostatic connector, and a weight of 431 g for the headphone alone or 491 g with the cable attached.

On sound, the press release offers the manufacturer's own description rather than any independently verified claim: SJY says it has voiced the ARGOS with "a natural, slightly warm balance" rather than a strictly linear response, aiming to add body to bass and presence to vocals. That is SJY's characterization, not a measured or reviewed result, and Into The HiFi has not tested the headphone.

Apos x ES Lab HYDRA: one amplifier, four load types

The HYDRA integrated amplifier lists at $2,200, with a pre-order price of $1,980 during the current pre-order window, per its Apos product page. Apos describes the HYDRA as combining two separate amplification paths in one chassis: a low-noise 580V DC bias supply for driving electrostatic headphones, and a Class AB power amplifier stage rated at 20 watts per channel into 8 ohms for everything else.

Between those two stages, Apos states the HYDRA is built to drive four distinct load types: electrostatic headphones, planar magnetic headphones, dynamic-driver headphones, and passive loudspeakers. That range is why the product is positioned as an integrated amplifier rather than a headphone-only energiser — the same chassis can, according to the listing, feed a pair of passive speakers off its 20W-per-channel Class AB stage. Apos's listing does not make any claim about which speakers that power figure would suit, and no such recommendation is made here.

Connectivity, per the product page, includes one balanced XLR input and two single-ended RCA inputs on the way in. On the output side there's a standard headphone output alongside a 4-pin XLR "Direct" output, which Apos describes as giving more demanding headphones direct access to the power amplifier stage rather than routing through the headphone circuit.

Why the pairing matters

Electrostatic headphones don't work with ordinary headphone amplifiers. The driver diaphragm needs a constant high-voltage bias charge — in this case 580V — supplied by a dedicated energiser, plus an audio signal stepped up to much higher voltage swings than a dynamic or planar driver needs. That's the specific gap the HYDRA is built to fill for the ARGOS: matching bias voltages and a shared 5-pin Pro Bias connector are what let Apos position the two as a working pair, rather than as separate purchases that happen to share a shelf. Apos's listings don't extend that compatibility claim to any third-party electrostatic energiser, and no such claim is made here either.

Pricing, availability, and what's still unconfirmed

Both products are currently listed as pre-order only, with Apos quoting the reduced pre-order prices against the eventual list prices — $1,620 versus $1,800 for the ARGOS, and $1,980 versus $2,200 for the HYDRA. Apos states both are expected to ship "on or before" 15 October 2026, language that leaves room for the date to move earlier or, more likely in practice, to slip. No source specifies an end date for pre-order pricing, and no source addresses sale, pricing, or distribution of either product outside the United States.

Because both are newly announced and unreviewed, there's no independent data yet on how the ARGOS's driver measures against other electrostatic designs, or how the HYDRA behaves at full output across its various load types. Anyone tracking the launch is, for now, working from the manufacturer's own specification sheets rather than third-party testing.

Frequently asked questions

What is the price of the SJY Argos electrostatic headphones?

According to Apos's product page, the SJY Argos lists at $1,800, with a reduced pre-order price of $1,620 during the current pre-order phase. No end date for that pre-order pricing has been published.

What driver and bias does the SJY Argos electrostatic headphone use?

Apos states the SJY Argos uses an electrostatic driver with a stated area of 6,375 sq mm, run on a 580V Pro Bias supply, with a 5-pin Pro Bias connector and a stated capacitance of 130 pF measured with its 1.5 m cable, per the manufacturer's product page.

What loads can the Apos x ES Lab Hydra amplifier drive?

Apos states the Hydra is built to drive four load types: electrostatic headphones, planar magnetic headphones, dynamic-driver headphones, and passive loudspeakers, combining a 580V DC bias supply with a Class AB power amplifier stage rated at 20 watts per channel into 8 ohms.

When will the SJY Argos and Apos x ES Lab Hydra ship?

Both products are listed by Apos as expected to ship on or before 15 October 2026. That is the vendor's own hedged timeframe; no firm delivery date has been confirmed.

What inputs and outputs does the Apos x ES Lab Hydra amplifier have?

Per Apos's product page, the Hydra has one balanced XLR input and two single-ended RCA inputs, plus a standard headphone output and a 4-pin XLR Direct output described as giving demanding headphones direct access to the power amplifier stage.

This article was written by an AI system from Into The HiFi AI Desk, generated from the following sources, with no human editing pass before publication: Press release via The AI Journal, "Apos Launches ARGOS and HYDRA, Bringing Electrostatic Hi-Fi to a New Generation", SJY Argos Electrostatic Headphones product page, Apos x ES Lab Hydra Integrated Amplifier product page.