Cayin Soul 170HA

Massive EI core output transformers plus dual power transformers for the high and low voltage sections are designed and wound in-house, to Cayin's exact spec. These allow Soul 170HA to take total advantage of its choke-input power supply, transferring pure potency to your giant flagship headphones.

But don't let such raw power scare you, your sensitive Focals, ZMF Headphones ... or even your IEMs. Soul 170HA retains the sensuality that has defined Cayin alongside brute strength. This behemoth on its XLR outputs turns delicately tactile on its alternative 4.4mm output – 18 would-be watts usefully reduced, to a maximum of just 4 watts.

It is this Jekyll-and-Hyde nature of Soul 170HA – enabled by the different taps on its output transformers – that means Head-Fi should take this flagship very seriously. A JRC MUSES72320 volume control shows up, proving how Cayin meant for more than just Susvara, Abyss Headphones and Dan Clark Audio owners to enjoy this do-it-all amp.

These resistor ladder electronic volume parts preserve signal-to-noise ratio and channel balance down to the ALPS-controlled encoder's lowest level – perfect for however much, or little, travel you need. 

Not a one-dimensional bull in a china shop, Soul 170HA still adds all the fidelity and finesse you can reap from the whole world of flagship equipment that can be enjoyed today – gear that's easy to drive, including IEMs, is certainly not exempted.

Cayin naturally provides all the fidelity, and power, the Susvara Unveiled needs. But when that speaker-amplifier level of power's not needed, Soul 170HA has more than enough fidelity to stand upon that alone and make its case. Built to work in single-ended Class A, Soul 170HA preserves the all-important even harmonics that tube enthusiasts crave.

Certainly none of those push-pull, odd harmonic nasties that's a painful shortcut to easy output power yet a route to non-linearities in the process. With Soul 170HA's huge, regulated power supplies, Cayin have ensured its single-ended KT170 pair sit in their sweet spot of bias and operating voltage, while outputting their huge power.

Said power supply is perfectly designed to lavish New Sensor Corp's 2021 wonder tube's great plate dissipation and robust cathode. Housed in a separate chassis, comprised of dual toroidal transformers – one for the massive voltages of tubes, and a different one for the low voltage sections to avoid contamination – Cayin tagged these to a huge choke input. 

This choke operates in tandem with a capacitor bank and regulation to ensure Soul 170HA enjoys vast power reserves. Soul 170HA's reservoir is unleashed into impossible loads during big transients via dual umbilical cords connecting the two chassis, so that neither feed contaminates the other.

Cayin's protection from interference is yet another factor that adds up to Soul 170HA's fidelity – and the resulting point of owning one. Soul 170HA will undisputedly improve any transducer you use, whether or not you require all 18 watts off its 4-pin XLR, or barely approach the limit of its ubiquitous 4.4mm's max 4 watts.

Soul 170HA can attribute that claim to its excellent linearity in the open loop. What enters comes out the same, not relying on the excessive use of negative feedback. Without counting on common-mode rejection, its achievement of 110dB signal-to-noise ratio is a great feat and testament to thorough, good old-school engineering.

A point-wired, simple tube circuit guarantees purity. Custom-built AudioCapX MultiCap coupling capacitors in Soul 170HA's signal path are ideal for passing low frequencies and extending bass down to 10Hz.

Phase reproduction in the audible human hearing range remains stellar as a result, with taut dynamics and impactful bass slam – not the wooly affairs of yesteryear's transformer amps.

Helped by huge output transformers, with enough inductance to reproduce sub-notes low, plus Cayin's hand-wound EI shape to allow high frequencies through, Soul 170HA performs very satisfactorily in moving drivers full-range ... and is even capable of transferring its full 18 watts of ultra-linear power out into high-impedance, high-sensitivity speakers through taps on the rear.

Again the reasons for Soul 170HA's range of highest possible output power, to delicate and soft playback, surface clearly: to reproduce its magnificent KT170 tube fidelity into any kind of load possible.

Buy Cayin's champion now, and rest forever assured you have the best foundation for flagship tranducers – present and future – to perform. But if space and weight are a constraint, however, look towards Cayin's own HA-300B and HA-6A in more compact form factor for Susvara-driving power still.

And, when on the go, bring out one of Cayin's DAPs here, as you browse the rest of our desktop equipment here too.