ZMF Aegis

ZMF Aegis

Transformer-coupled tube amplifier with cathode follower – the first collaboration between ZMF and L0rdGwyn

The Aegis started life as a DIY amplifier: Keenan McKnight, known in the headphone community as L0rdGwyn, designed it for home builders in 2022. Zach Mehrbach of ZMF heard the DIY version at CanJam SoCal 2022 and, together with Keenan, turned it into a production model. The design comes from ZMF; the Aegis is built by Cayin.

Technically, the Aegis is a transformer-coupled tube amplifier with a cathode follower: here the tubes mainly provide current rather than additional voltage gain. The result is a low output impedance and a high current capability – a good basis for headphones of very different impedances. ZMF explicitly includes hard-to-drive planars such as the Hifiman Susvara. Depending on the load and impedance setting, output power ranges from 1 to 2.5 W, averaging 2 W (calculated by ZMF for headphones from 8 to 300 Ω).

A three-position switch on the front selects the output impedance, separately for the two main outputs: 5, 11 or 31 Ω at the 6.35 mm jack, 11, 28 or 85 Ω at the 4-pin XLR. This lets you match the Aegis to each pair of headphones and to your own taste. The 4.4 mm socket has a voltage divider with an output impedance of 2 Ω; it is intended for very sensitive headphones and IEMs and is used in the “Low” position.

The Aegis is built for tube rolling. From the factory it runs on tubes from JJ Electronics: two EL34 in the output stage, two 6SL7 at the input and one GZ34 as rectifier. The output stage also accepts 6V6, 6L6, EL37, KT66, KT77, KT88 and 6550, the rectifier position 5AR4, 5V4/GZ32, 5R4, 274B, 5Y3 and 5U4G. This means the sound can be shaped over a wide range through your choice of tubes.

The styling draws on cockpit instruments and classic equipment from Chicago such as Zenith: two illuminated VU meters with the ZMF logo, a walnut faceplate, chassis and transformer covers in the “Foundry Copper Vein” finish, plus volume knob, accent plate and power button in copper. The source connects via a pair of RCA inputs (20 kΩ); the Aegis has no preamp output. At 36 × 29 × 20 cm and almost 21 kg, it needs a sturdy, permanent place.

We supply only the 230 V version with CE marking for European mains. The photos show the Aegis with ZMF’s optional TAD tube set (KT88, 6SL7, 5U4G); it is delivered with the standard JJ Electronics tube set.

What the press says

Hi-Fi Pig – review by Oscar Stewart (July 2026)

“The ZMF Aegis is a cracking headphone amp; it works well with a huge range of headphones and delivers an engaging and spacious sound. […] Its ability to work with sensitive dynamics, all the way up to hard-to-drive planars, is brilliant.”

Headfonics – review by Marcus (December 2024)

“It has a beautifully smooth but weighty tone, awesome gear flexibility including IEMs, and looks the ‘ZMF business’ as only a ZMF piece of gear can.”

Who is the Aegis for?

For anyone looking for one tube amplifier for many different headphones – from sensitive IEMs on the 4.4 mm socket to high-impedance dynamic headphones and power-hungry planars. And for anyone who enjoys tube rolling: the Aegis accepts a wide range of output tubes and rectifiers.

Technical specifications