Apos Gremlin Headphone Amp — Class A, Fully-Balanced Tube Hybrid

Meet the Gremlin: Apos's compact Class A, fully-balanced tube headphone amplifier

The Gremlin is a compact, beastly-sounding headphone amplifier that pairs a Class A buffer with a hybrid tube design. With 1250 mW of output at 32 ohms, it has enough muscle to drive a broad range of headphones while keeping a warm, musical character. Its small, minimalist chassis hides a big-sounding personality, delivering lush mids and rich harmonic texture without overwhelming the rest of your desktop setup.

Hybrid warmth and precision come from the blend of tubes and transistors. The pre-amp stage uses vacuum tubes to flood the signal with harmonics, while the solid-state elements preserve detail. The result can feel both intimate and expansive, depending on your source and headphones.

Balanced design for cleaner signal

The Gremlin uses a fully-balanced architecture from input to output. Balanced XLR inputs and balanced 4.4 mm / 4-pin outputs help reduce hum and crosstalk, which is especially helpful with sensitive headphones or high-end rigs.

Key specs include a low noise floor of 100 dB and strong channel separation of 104 dB. It supports headphones from 8 ohms up to 600 ohms, making it a versatile desktop amplifier for many setups.

Tube pairing and swap potential

Out of the box you get a matched pair of Ray Tubes CORE 12AU7, chosen to deliver signature tube warmth. The Gremlin also supports 12AU7 or 6922 tubes, new or vintage, so you can roll tubes to tailor the texture and response.

For listeners who love experimentation, consider upgrading to the SELECT version to access both matched pairs and a broader range of tonal options.

Why readers choose the Gremlin

Real-world listening notes emphasize engaging tonal balance, detailed mids, and a sense of space in the soundstage. The compact form factor makes it a practical companion on a desk or in a small home studio. It’s designed to be a flexible starting point for exploring tube texture without a high price tag.

• Class A operation provides a consistent signal path with minimal switching distortion, according to design goals.
• Fully-balanced interface helps keep interference low for clear, precise playback.
• Swap-friendly tube compatibility invites listening experimentation and tonal shaping.
• Wide headphone compatibility covers a large impedance range for most headphones.

Note that while the Gremlin aims to offer a refined listening experience, results depend on the rest of your chain and headphones. This description highlights possibilities rather than guarantees.