Усилители мощности стерео — Schiit Audio GJALLARHORN F

The Gjallarhorn F is a small Schiit Audio stereo power amp aimed at desktops, nearfield monitors and small rooms. Design and build are American, with chassis from California, boards from California or Nevada and assembly in San Antonio, and it sells for USD 299 with black and silver finishes and an optional Forkbeard module. Gjallarhorn is Heimdall's horn in Norse mythology. The chassis is the same size as the Schiit Asgard, Jotunheim and Bifrost 2.

Key specs that matter

Rated output is 10 W RMS per channel into 8 ohms and 15 W into 4 ohms in stereo, or 30 W into 8 ohms when bridged to mono. Frequency response is 20 Hz to 20 kHz within 0.01 dB and 3 Hz to 500 kHz within 3 dB. THD is below 0.004% and IMD below 0.005% CCIR, both at 1 V RMS into 8 ohms. SNR exceeds 117 dB unweighted referenced to full output, the damping factor is above 100 into 8 ohms and crosstalk is better than 80 dB. Gain is 10 times (20 dB), and input impedance is 20 kohm on RCA and 40 kohm on XLR. The amplifier draws up to 80 W, measures 229 x 152 x 64 mm and weighs 3.6 kg.

Engineering and use context

Schiit made the gain circuit fully discrete, fully complementary current feedback, with -3 dB above 1 MHz before the input filter, and the whole path is DC coupled, free of signal capacitors. Every channel carries two pairs of 10 A output transistors, one pair forming the Continuity S stage for better transconductance linearity. The linear internal supply uses an 80 VA toroidal transformer with 30,000 uF of main-rail filter capacitance plus 13,200 uF for separate discrete regulated boost rails feeding the input, voltage gain and driver stages. Those boost rails are ground-referenced rather than stacked so that each channel works independently. Over-current and over-temperature sensing and a DC servo protect the amplifier without active devices or current limiting in the signal path. The board has four layers, and the design uses neither Class D output, a switching supply nor a fan. The Forkbeard module adds app readout of instant power output, health alerts and remote standby.

Pairing

Stereo input is through L and R RCA jacks, and a single XLR input drives a channel in mono, so two units fed from a fully balanced preamp output work as monoblocks. Schiit suggests pairing with the Saga 2 preamp, controlled through the same Forkbeard app, or with any Schiit headphone amp.

Alternatives

The Schiit Vidar 2 is the larger stereo power amplifier in the Schiit range with a similar gain stage and linear supply.