FiiO GIGAS 1 Desktop Headphone Amplifier - Orange

The GIGAS 1 is a compact desktop headphone amplifier built to give full-size headphones, including entry-level planar magnetic designs, far more driving power than a computer, phone or portable player can manage on its own. It is a purely analogue amplifier with no built-in DAC: connect any line-level source to its RCA or 3.5mm input, plug your headphones into the 4.4mm balanced or 3.5mm output, and the GIGAS 1 handles the amplification. It is sold under JadeAudio, FiiO's entry-level sub-brand, and is available in four finishes; this one is Orange.

Discrete Class AB Amplification

The amplifier stage is a discrete Class AB design that pairs an op-amp with a transistor current-amplification output built on four onsemi MJE243G and four MJE253G transistors. This gives high current delivery and low output impedance, which is what lets a unit this small drive demanding headphones. Headphones from 8 to 350 ohms are supported. The GIGAS series was created to partner FiiO's JT7 planar headphones, whose low sensitivity calls for more power than most affordable sources can provide, and the same applies to entry-level planars from other brands.

Output Power and Gain

Output depends on how the amplifier is powered. From a standard 5V USB supply the balanced output delivers 580mW per channel into 32 ohms, enough for most headphones and IEMs. With a 12V USB Power Delivery supply the same output rises to 4600mW per channel into 32 ohms, with 740mW per channel still available into 300 ohms. The 3.5mm single-ended output gives up to 1400mW per channel into 32 ohms on 12V. A front-panel toggle switches between low and high gain: low gain suits sensitive IEMs, high gain suits low-sensitivity planar and high-impedance headphones.

Connections

The rear panel carries a stereo RCA input, a 3.5mm line input and the USB-C power socket. On the front are the power toggle, the gain switch, a 3.5mm single-ended headphone output and a 4.4mm balanced output, and both headphone outputs can be used at the same time. The 3.5mm output supports CTIA-standard microphone pass-through, so a gaming headset with an inline microphone can be used for voice chat when connected with a four-pole cable, which makes the GIGAS 1 as well suited to a gaming desk as to a hi-fi one. FiiO advises against feeding the RCA and 3.5mm inputs simultaneously, as the two signals would be mixed together.

Power Supply

Power comes in over a single USB-C port and the amplifier automatically adapts to whatever it is given: 5V at 2A from a computer port or phone charger, or 12V at 2A from a USB PD charger. A USB-A to USB-C cable is supplied but no mains adaptor, so a PD charger capable of 12V output is needed to unlock full power. The discrete output stage runs warm in normal use, particularly on 12V.

Design

The anodised aluminium alloy chassis measures 132 x 60 x 40mm excluding feet and weighs 210g, so it takes up very little desk space. An oversized top-mounted volume knob with a warm LED ring provides the main control, with mechanical toggle switches for power and gain. Alongside this Orange version, the GIGAS 1 is offered in Black, Silver and Green.