ЦАПы — Aries Cerat Ithaka Digital

The Ithaka is an R2R converter in the Ianus series of Aries Cerat, the manufacturer from Cyprus. Its recommended retail price is EUR 82,000. It combines a large R2R ladder converter with a TriodeFet output stage strong enough to drive a loudspeaker directly.

Key specs that matter

Conversion uses 24 AD1865N-K R2R ladder chips per channel, arranged in two banks of 12, with no digital filter. The I/V conversion is transformer-based, and an internal Super Clock provides the timing. The output stage is a third-generation TriodeFet in single-stage, single-ended Class A with 1 A of idle current. Output impedance is 1 ohm on both balanced and single-ended outputs, output level is 30 V peak to peak, or 10 V RMS, at 0 dB, and the minimum load is 3 ohms. The stage can deliver 12 W into a loudspeaker. Inputs are USB up to 24 bit and 384 kHz, AES/EBU, S/PDIF and BNC. Outputs are two pairs of floating RCA with a switchable ground and two pairs of balanced XLR. The power supply uses two 500 VA toroidal transformers and more than 4 F of capacitance. The unit measures 540 x 580 x 165 mm and weighs 160 kg unpacked.

Engineering and use context

An R2R ladder converts each digital word into a voltage using a network of precision resistors, and using 24 chips per channel spreads the conversion across many devices. Without a digital filter, the samples are converted without oversampling. Transformer I/V conversion turns the current output of the chips into a voltage through a transformer instead of a resistor or op-amp. The TriodeFet is Aries Cerat's own output device, and with its high idle current and low output impedance the stage can drive power amplifiers, long cables or even speakers. The floating RCA outputs with switchable ground can help avoid ground loops. With this power capability, the Ithaka can also act as a small single-ended amplifier for efficient loudspeakers.

Pairing

Its low output impedance and generous level let the Ithaka feed a power amplifier straight away, with no preamplifier in between, provided level control is handled elsewhere, and its balanced XLR outputs suit long cable runs to the amplifier. It suits Aries Cerat's own amplifiers and other high-end systems with USB, AES/EBU or S/PDIF sources.

Alternatives

The Aries Cerat Ithaka Minor is the smaller version, using 12 R2R chips per channel and a first-generation TriodeFet stage with the same low output impedance.