Headphones amplifiers — Schiit Audio FULLA 2

The Schiit Fulla 2 is a USB-powered desk unit combining a DAC with a headphone amp, made by Schiit Audio in the USA. Launched at USD 99, it replaced the first Fulla, which was a small dongle, with a larger box closer in form to a shrunken Magni 2 and aimed at desk use rather than portable listening. A later Fulla 3 kept the same basis and added a microphone input, which the Fulla 2 does not have.

Key specs that matter

Digital conversion is handled by an AKM AK4490 chip followed by a filter stage based on a TI OPA1662. Amplification is dual mono, with one TI LMH6643 per channel. The USB input accepts PCM from 16 bit and 44.1 kHz up to 24 bit and 96 kHz and needs no drivers on Windows, Mac, Linux and Android. Schiit rates the maximum output at 360 mW per channel into 32 ohm and 40 mW per channel into 300 ohm. Power comes from USB at 5 V and 500 mA, and repairs are covered for two years.

Engineering and use context

Two separate micro-USB ports are fitted to the unit - one carries data and power from a computer or mobile device, and the other accepts power only, so a separate USB charger can supply the amplifier while a phone or tablet provides the signal. The front panel carries a 6.3 mm headphone jack and a 3.5 mm analogue input, which lets the Fulla 2 work as a plain headphone amplifier for an external source. At the rear there are two 3.5 mm outputs - a fixed-level line output taken straight from the DAC that bypasses the amplifier, and a variable-level output for powered monitors or amplifiers without a volume control. Volume uses an Alps analogue potentiometer turned by a knob on the top panel. Taken together, this set of connections allows the one small box to act as a USB DAC, a headphone amplifier and a basic preamp for active speakers.

Pairing

The power available into low impedances suits most low and medium impedance headphones, while the much lower output into high impedance loads is a limit to keep in mind with such models. Schiit notes that the Fulla 2 cannot deliver the same power as a Modi 2 and Magni 2 stack, so demanding headphones are better served by separates. The variable output can drive active desktop monitors directly. When a phone or tablet is the source, any USB charger that meets the power requirement can power the unit through its second port.

Alternatives

For a dedicated amplifier without a built-in DAC, Schiit also makes the Vali 3 headphone amp.