Интегральные усилители — Rega io

The io is the smallest integrated amplifier from Rega Research, a Class A/B design built in England that uses the same amplifier stage as the Brio, here set up to run at 30 W RMS per channel into 8 ohm with both channels driven. It includes a phono stage, a headphone output and a mini remote control in a custom chassis.

Key specs that matter

Three RCA inputs are fitted - input 1 is the phono stage, and inputs 2 and 3 are line level. Phono sensitivity is 2.1 mV at 47 kohm in parallel with 220 pF, with a maximum input level of 100 mV. Line sensitivity for inputs 2 and 3 is 210 mV at 47 kohm, and the line inputs accept up to 10.25 V. Line frequency response runs from 12 Hz at the -1 dB point to 43 kHz at the -3 dB point. The phono path spans 15 Hz to 40 kHz at -3 dB or 27 Hz to 20.5 kHz at -1 dB, and its RIAA accuracy from 100 Hz to 10 kHz is within 0.4 dB, typically better than 0.3 dB. The case measures 180 x 68 x 290 mm and weighs 2.9 kg, and power consumption is 135 W at rated output, dropping to 0.0 W in off mode.

Engineering and use context

Sanken output transistors, an Alps volume potentiometer and a linear power supply form the core of the design. The front 3.5 mm headphone socket is driven from the power amplifier stage through relays, and inserting a plug turns the speakers off automatically. Rega quotes headphone output of 8 V with no load, 1.6 V into 32 ohm, 2.4 V into 54 ohm and 5.7 V into 300 ohm, with a source impedance of 109 ohm. Fold back short circuit protection guards the output stage against shorted speaker leads and sits outside the audio signal path. A grounding nut on the back panel serves third-party tonearms with a separate earth lead, while Rega turntables ground through the phono lead. Inputs are chosen with a small button that lights the selected number in red, or from the remote, which also handles mute. The volume setting is kept between sessions rather than reset, and the remote's two AAA alkaline cells are supplied.

Pairing

The phono input suits moving magnet cartridges and, according to Rega, specifically high output moving coil types. Rega advises loudspeakers with a nominal impedance of 6 to 8 ohm. Speakers down to 4 ohm can be used, but continued high level use into that load may push the case above 40 degrees C over ambient. Fuse ratings are T1.6AL for 230 V and 220 V mains and T3.15AL for 115 V and 100 V. Rega also sells the io as part of System One together with the Planar 1 turntable and Kyte loudspeakers.

Alternatives

The Rega Brio is the integrated amplifier whose power stage the io shares.