Direct Heated Triode
Vacuum Tube Headphone Amplifier
The Star is Reborn
Work hard and dig deep with
20 years of impeccable track record.
Pushing the envelop of tube amplification to
deliver practicality, performance and refinement.
Tube Amplifier Holy Grail
The Pursuit of Direct Heated Triode (DHT)
DHT refers to triode tubes that use the cathode as
the filament and will heat up the cathode directly.
Minimal approach, offers stellar dynamic, transient
and transparent, extremely well-received by audiophiles.
A challenge for headphone applications. Low tolerance to
shock and vibration, sensitive to hum/interference.
The Irresistible 300B
The 300B is the most renowned and sought after DHT
because of its dreamy tonal characteristic.
HA-300MK2 uses a matched pair of Gold Lion Genelex
PX300B low-noise audio triode as power output tubes.
• Endure and passed the toughest tests for reliability
• Natural, sensible and realistic sound signature
• Impressive frequency extension
Purist’s One-Way Ticket
Less is More
Single-ended Triode (SET) Amplifier uses a single triode
vacuum tube to produce amplified output without
splitting the musical signal into parts.
2-stage amplification, a pair of driver tube amplifies
signal voltage so that the 300B output tube will perform
its amplification at a very linear condition.
Simplicity circuit design. Displace the beautiful tone of
your vacuum tubes without any cancellation.
Single-ended Driver Stage
Cayin developed many 300B based SET amplifiers and
6SN7 is always the first choice for driver tube.
HA-300MK2 uses a matched pair of Tung-Sol 6SN7GTB
to complete the two-stages SET amplification.
• Low noise, high price-performance and highly reliable
• Super linear and natural sounding
• A classical tube combination adopted in many
Cayin SET amplifier implementations
Tube Regulated Power Supply
Outboard Power Supply minimize ripple effect, offer a
clean, low-noise power to amplification circuit.
Multi-stage tube regulated power supply circuit, feed
power to different amplification stages independently.
New Old Stock (NOS) Rectifier Tubes
HA-300MK2 uses 4 x NOS 22DE4 from RCA, one of the
best versions of 22DE4 available in tube market
Convert incoming power source to DC current,
provides cleanest power with minimum interference
for the amplification circuit.
• Unlike output tubes, rectifier tubes don’t involve heavy
lifting load, they can last very long without deteriorate.
• No matching requirement, replace on per piece based.
Power Supply Transformer
The outboard power supply is driven by a high
inductance high efficiency toroidal power transformer.
Cayin design and wind the Power transformers in-house.
Low leaking design for headphone applications.
Premium Vacuum Tubes
Driver Tubes: Tung-Sol 6SN7GTB (Matched Pair)
Output Tubes: Genalex PX300B (Matched Pair)
Rectifier: NOS RCA 22DE4 x 4
Balanced Driven from Single-ended Triode Amplifier
The 300B SET output drives a pair of proprietary output
transformers, support both headphones and speakers.
The secondary winding of the output transformers
provide an alternative phase and compose a balanced
output, enables balanced driven from an SET
Both single-ended and balanced headphone output are
"original" outputs from the transformers.
In-house Designed and Winded Transformers
With a pair of EI Transformers, HA-300MK2 delivers a
natural and realistic sound across the frequency range.
Cayin design and wind the all transformers in-house
because they play a vital role in our amplifiers.
• Total freedom in specifying the requirements and
• Total control on material and craftsmanship.
This Is All You'll Ever Need
Impedance Matched Phone Out
Optimized its output to handle the headphone loading
according to three headphone impedance settings
Low (L): 8Ω~64Ω; Medium (M): 65Ω-250Ω; High (H): 251Ω~600Ω.
Matching headphone impedance should produce a natural
sound with well-defined bass reproduction, it is different
from gain control of solid state amplifier.
Planar Headphones are more sensitive to impedance
matching than dynamic headphones but users can try out
different impedance settings.
Carefully Optimized Headphone Outputs
HA-300MK2 offers three headphone outputs: 6.3mm
single-ended, 4.4mm balanced, and 4-pin XLR balanced.
The XLR4 output is a full-fetched output but the 4.4mm
output is optimized for wider range of headphones,
including high sensitivity portable headphones.
• 4.4mm is level-matched, lower noise, lower power
output with the same audio performance
• at LOW headphone impedance, the 4.4mm output
delivers roughly 70% of 4-pin XLR output only.
Powerful and Effortless
Combinations all audiophiles will cherish and admired:
purity of single-ended triode amplifier, dreamy sound
signature of 300B, and authoritative dynamic and control
when called for.
With up to 6w per channel, provides all the power you
need to handle vast selection of headphones, from
portable friendly dynamics to extremely demanding
Low noise low distortion electronic controlled resistor
ladder analogue volume controller JRC MUSE72320V,
commonly used in high-end preamplifiers and streamers.
4-channel in one integrated controller offers high
precision and zero channel imbalanced.
ALPS balanced potentiometer as 41-steps encoder to
provide precise and intiuative control that we are all
Interface Facilitates Functions
Lock-on & quick-release aviation grade copper connectors.
Silver plated Teflon umbilical cable connects between
outboard power supply and amplifier circuit.
Balanced (XLR) and Single-ended (RCA) to cover a
variety of inputs.
Balanced input will go through a pair of input
transformers, the + and – half cycle will merge to
become a single-ended signal.
Users can toggle between speaker and headphone
With 8W per channel Class A output, the amplifier can
driver high sensitive speakers, or common bookshelf
speaker in a small listening area.
High quality solid brass speaker terminals.
Enhance Your Daily Usage
Anti-Interference Improves Listening Experience
Custom-made silica gel shock absorbers between critical
tube components, chassis mainframe and tube socket,
remove microphonic effectively.
Reinforcing shielding of transformers and effective circuit
layout to minimize interference.
Delay Can Be Desirable
60sec startup delay circuit.
Enhances circuit protection and minimizes pop noise
Specially designed vacuum tube shielding cage to
protect users from touching the red hot vacuum
tubes during operation.
Removing and installing with ease, safe and flexible
for different needs.
The Art of Black Finishing
13.5mm brushed Aluminum-Magnesium Alloy
front panel, added strength and corrosion
resistance to the amplifier.
The panel is black anodized, it is extremely
durable and protect the amplifier from
The Hidden Details
The chassis and transformer pots are treated by
our proprietary 14 rounds of crafting process
composed of scratch, spray, sanding and baking.
The high gross final finishing endows a refined
and delicate texture as well as protecting the
amplifier from years of long service.