Cayin Soul 170HA

Cayin Soul 170HA

Single-ended Class A with KT170 – Cayin's big two-box amplifier for headphones and speakers

Alongside the HA-300 MK3, the Soul 170HA is the second flagship in Cayin's headphone range – and its counterpart: instead of the directly heated 300B it runs a matched pair of Tung-Sol KT170, currently the most powerful tube of the KT family, in whose development Cayin was involved. The result is a single-ended Class A amplifier that delivers up to 18 W per channel – enough not only for any headphone but also for 4–8 Ω loudspeakers.

Two JJ 6SN7 form the driver stage, two JJ GZ34S rectifier tubes in the separate power supply chassis provide the high voltage. The multi-stage, tube-regulated supply feeds each amplifier stage independently; the two-box design keeps mains transformer and signal path physically apart and improves heat dissipation – the two chassis can be stacked or placed side by side. Cayin winds all mains and output transformers in house.

As on the HA-300 MK3, the output stage switches between triode and ultralinear operation: triode for a soft, three-dimensional presentation focused on voices and midrange, ultralinear for more power, dynamics and openness with large orchestral works. An auto-bias servo circuit removes the need for manual adjustment when changing tubes; an MCU supervises start-up, operation and shutdown with several protection circuits.

Headphones connect via 4-pin XLR, 4.4 mm Pentaconn or 6.35 mm jack; a three-step impedance selector (8–64 Ω, 65–250 Ω, 251–600 Ω) matches the transformers to the headphones in use. In ultralinear mode the XLR output provides up to 18 W – ample headroom even for the least sensitive planar designs. Inputs: one pair each of XLR and RCA. Volume is handled by a 128-step system of ALPS potentiometer and JRC MUSES72320 chips, also from the supplied remote control.

The entire audio circuit is hand-wired. Amplifier (330 × 400 × 231 mm, 23.3 kg) and power supply (330 × 363 × 114 mm, 17.2 kg) weigh a good 40 kg together – a component for a permanent place in the listening room, not for the desk.

What the press says

STEREO 3/2025 – Michael Lang

„Wir müssen gestehen, wir haben noch nie zuvor derartig räumlich und emotional fesselnd über Kopfhörer Musik gehört. […] Denn wer ihn gehört hat, wird die Kopfhörerwelt und ihre Möglichkeiten mit neuen Augen betrachten und anerkennen, dass hier Maßstäbe verschoben worden sind.“

Sound quality: very good (1.2). German review – "We have to admit we have never heard music through headphones in such a spatially and emotionally captivating way. Anyone who has heard it will look at the headphone world with new eyes and acknowledge that standards have been shifted here."

Who is this for?

For anyone who wants the most powerful tube amplifier in Cayin's range – for hard-to-drive planars as well as for a second role with efficient loudspeakers. If you are after the finesse of the 300B, choose the HA-300 MK3; if you want power, dynamics and headroom, the Soul 170HA.

Technical data