Интегральные усилители — Esoteric F-02

The F-02 is an integrated amplifier from Esoteric of Japan that pairs a balanced dual mono preamp and phono stage with a high-power output section. Esoteric says the power stage borrows its circuit layout from the Grandioso M1X monoblock, while the line stage takes over ideas from the Grandioso C1X preamplifier.

Key specs that matter

Esoteric rates the output at 120 W per channel into 8 ohm and 240 W into 4 ohm, and 4 ohm is the minimum load Esoteric specifies. For line sources there are three RCA pairs and three XLR pairs that can each be switched to ES-Link Analog, all at 10 kohm. Phono is MM/MC switchable with loads of 47 kohm and 100 ohm. Frequency response reaches 10 Hz to 100 kHz within 3 dB, S/N is 110 dB IHF-A and THD is 0.008% measured at 1 kHz with 120 W into 8 ohm. The damping factor is given as 500 and the power amplifier gain as 28.5 dB, with up to 18 dB more from the preamp. Measured at the pre-outs with 1 V, S/N is 110 dB for line inputs, 97 dB for MM and 78 dB for MC. The case is 445 x 191 x 471 mm and 32.4 kg, and power draw is 320 W, falling to 110 W at idle.

Engineering and use context

Esoteric fits its UFA-1792 attenuator module here, giving 0.1 dB resolution over 1,120 steps. Sources are selected by FET switches rather than mechanical relays. A dedicated transformer winding and rectifier board feed the preamp, with the logic control section kept apart and linked by a photocoupler. The power stage relies on a bare-mounted 940 VA EI transformer and a dual mono supply of four 10,000 uF Grandioso-grade capacitors per channel. Bipolar transistors run in three parallel push-pull pairs with a coil-less output and minimal feedback. The front door hides a balanced headphone amp with 600 mW per channel into 32 ohm from the 4-pin XLR socket and 300 mW from the 6.3 mm socket, into loads of 16 to 600 ohm unbalanced or 32 to 600 ohm balanced. Treble, middle and bass controls work at 14 kHz, 630 Hz and 63 Hz with a range of 12 dB either way. The chassis is built from aluminium blocks and carries wave-shaped heat sinks and a top plate on a semi-floating mount. Standby draw is 0.3 W, or 0.6 W with RS-232C active, and trigger input and output jacks are fitted.

Pairing

The pre-outs, in XLR and ES-Link Analog, allow an S-05 power amplifier to be added for multi-amping, and the PS-01F external supply can power the preamp section. The option slot takes the OP-DAC1 D/A board or the OP-ESLA1 input board, and the aluminium RC-1339 remote is supplied.

Alternatives

The Esoteric F-01 is the Class A integrated amplifier in the same F Series, with a lower-power output stage.