With the HA-1A Mk3, Cayin offers a relatively affordable entry point into its world of vacuum tube headphone amplifiers. The single-ended Class A circuit, which operates entirely with vacuum tubes, delivers up to 2.8 watts per channel and can be adapted to headphones with impedances between 8 and 600 ohms. Via the adjustable RCA output, the amplifier can also function as a tube preamp when needed.
Two clearly visible EL84EH power tubes from Electro-Harmonix and the point-to-point hand-wiring already create the classic tube amplifier aesthetic. Technically, the HA-1A Mk3 is designed to deliver sufficient power and a low enough noise floor to drive both demanding electrostatic speakers and sensitive headphones.
One EL84 for the entire channel
Two JJ 12AU7s (also known as ECC82s) handle the voltage amplification. Power amplification is handled by two Electro-Harmonix EL84EHs, also known as 6BQ5s. In this configuration, a single output tube is responsible for the entire signal path of a single channel. This corresponds to a classic single-ended circuit.
All tubes operate in Class A mode. Unlike in a push-pull output stage, this means the audio signal does not need to be split between two output tubes. Output transformers developed specifically for the HA-1A Mk3 handle the impedance matching for the connected headphones.
Through the balanced XLR-4 jack, the Cayin delivers up to 2.8 watts per channel. Via the unbalanced 6.35-millimeter jack output, the maximum power is 2.5 watts. The manufacturer specifies the frequency response as 20 hertz to 24 kilohertz with a deviation of three decibels.
From 8 to 600 ohms
A switch on the front panel adjusts the output transformers in two stages to suit different headphones. The “Low” setting is intended for models between 8 and 150 ohms, while “High” covers the range from 151 to 600 ohms.
With this, Cayin aims to cater to both low-impedance electrostatic headphones and classic high-impedance dynamic headphones. An A-weighted signal-to-noise ratio of 110 decibels is also intended to make the HA-1A Mk3 suitable for sensitive listeners with high sound pressure levels.
A power-on mute feature prevents unwanted noise during startup. The delayed startup sequence gives the tubes about 50 seconds to reach operating conditions before the outputs are enabled.
Hand-Wired Instead of a Printed Circuit Board
The amplifier circuit is assembled at the Cayin factory using point-to-point hand-wiring. The voltage and power amplifiers have separate power supplies. A regulated high-voltage power supply is also used for the output stage.
Internal shielding between the individual functional areas is designed to reduce mutual interference. A removable protective cage, available upon request, prevents direct contact with the hot tubes without completely obscuring their glow.
The compact amplifier measures 24 x 24 x 14 centimeters, but weighs in at a hefty 8.8 kilograms due to its transformers and power supply. The maximum power consumption is 60 watts.
Side Job as a Tube Preamplifier
The Cayin HA-1A Mk3 isn’t limited to powering headphones. Via an adjustable RCA pre-out, it can also drive active speakers or a separate power amplifier. The maximum output voltage is five volts, and the gain is nine decibels.
As an analog signal source, a device can be connected via a pair of stereo RCA jacks. Cayin has opted not to include a built-in D/A converter or digital inputs. The HA-1A Mk3 thus focuses entirely on analog tube amplification.
Cayin HA-1A Mk3: Price and Availability
The Cayin HA-1A Mk3 is now available with a silver or matte black front panel. The price is 1,298 euros, including VAT.
Further information:
https://cayin.com/produkt/cayin-ha-1a-mk3
