Integrated amplifiers — Ypsilon Electronics Phaethon neo

The Phaethon neo is the second generation of the hybrid integrated amplifier from Ypsilon Electronics, the Greek company headed by designer Demetris Baklavas, who winds the transformers by hand in Athens. The first Phaethon appeared in 2014 in a copper-wound standard version, a silver-wound SE version and a low-gain two-stage version for horn speakers. The neo keeps the hybrid layout of that model and reworks the circuit details, and it was first shown at the Vienna audio exhibition.

Key specs that matter

Ypsilon rates output before clipping at 110 W RMS into 8 ohm and 180 W RMS into 4 ohm. Bandwidth runs from 11 Hz to 75 kHz at -3 dB, gain is x60, output impedance is 0.5 ohm and input impedance is 47 kOhm. There are three RCA inputs and one XLR input, and Ypsilon lists both kinds as unbalanced. At idle the amplifier draws 125 W. Its case is 400 mm wide, 185 mm high and 425 mm deep, and the amplifier weighs 35 kg.

Engineering and use context

Three gain stages make up the signal path. A valve input stage comes first, and in the neo it is followed by an ultra-high-voltage solid-state driver device that replaces the double-triode driver of the original Phaethon, where one 6H30P or 5687 double triode served both the input and the driver stage. A purpose-designed interstage transformer, not a capacitor or a direct connection, couples the driver to the output stage. That output stage is a bridged single-ended circuit in which semiconductors of the same polarity handle both phases, it is biased in class A, and the neo uses three pairs of new output devices. The valve section and the output stage draw on separate power supplies, and the chassis holds five supply inductors, two mains transformers and four signal transformers. Lucas Baklavas, now a partner in the company, developed the new microcontroller and the high-resolution display, whose character colour the owner can choose. A remote control covers all functions.

Pairing

The neo holds up as the load falls from 8 to 4 ohm, so typical 4 ohm floorstanders are within its reach, while very inefficient speakers that ask for several hundred watts per channel are a poor match for this class A amplifier. Every input takes line-level signals, so a turntable reaches the amplifier through a phono preamplifier of its own. A source with XLR outputs plugs straight into the XLR socket.

Alternatives

Ypsilon makes no integrated amplifier outside the Phaethon family.