β24:
All discrete, fully differential, fully complementary, cascoded topology
with JFETs, BJTs and power MOSFETs. A reference class power amplifier
of no compromises, and a sight to behold both inside and out.
β22 and
σ22:
Brawn and finesse taken to a new height.
All-discrete, fully complementary, cascoded pure class A topology
with JFETs, BJTs and power MOSFETs -- the ultimate headphone amplifier
and a superb low-power amplifier for speakers, and an equally capable
companion power supply too.
Cavalli-Kan Kumisa III:
An all-discrete, fully complementary, no global feedback
headphone amplifier that belies its modest cost and size,
delivering sound that is simply sublime.
The
M³:
Three-channels of pure class A MOSFET power and exquisite sound.
Maybe you could build one for yourself too?
The
Dynahi:
Big, bold and hot, this pure class A discrete amplifier exudes
Kevin Gilmore's mantra that too much is not enough.
The
Mini³:
Miniature in size and cost, but big in performance. This
amplifier is rocking the DIY portable headphone amplifier scene.
The
γ1:
A full-featured miniature DAC that's proven to be a superior companion
for the Mini³.
The
γ2:
A compact high performance upsampling DAC upgrades the γ1 and its
modular concept deep into the high-end without the high cost.
The
β18:
A modified SDS Labs MOSFET amplifier originally designed
by Sheldon Stokes. This one started my headphone amplifier
infatuation.
I am a hi-fi audio enthusiast and hobbyist, and enjoy designing, building,
tinkering and listening to music systems. Those who read Chinese and have
similar interests may remember me as the author of a couple of regular
columns in the Audiotechnique monthly magazine (音響技術) from Taiwan
in the 1980s.
The β24 - A reference-class all-discrete,
fully-complementary, cascoded, fully-differential power amplifier.
(PCB and parts available)
The β22 - A reference-class all-discrete,
fully-complementary, cascoded, pure class A headphone amplifier.
(PCB and parts available)
The M³ - An opamp-MOSFET pure class A
headphone amplifier.
(PCB and parts available)
The Cavalli-Kan Kumisa III - An all-discrete,
fully complementary, non global NFB headphone amplifier,
originally designed by Benny Jørgensen and modified by
Alex Cavalli and myself.
(PCB and parts available)
The Mini³ - A small portable headphone amplifier
offering big performance.
(PCB and parts available)
The γ1 - A full-featured, modular, miniature DAC.
(PCB and parts available)
The γ2 - A compact, high-performance DAC.
(PCB and parts available)
The σ22 - A high performance, all-discrete,
fully complementary, dual-rail, tracking regulated power supply.
(PCB and parts available)
The σ11 - A high performance, all-discrete,
single-rail, regulated power supply.
(PCB and parts available)
The σ25 - A simple regulated power supply.
(PCB and parts available)
The ε24 - Power switch driver circuit with
thermal sensing/shutdown feature.
(PCB and parts available)
The ε12 - A muting delay and DC offset protection
circuit for headphone amplifiers.
(PCB and parts available)
The LCDuino-1 - A LCD I/O processor
platform for audio and other control applications.
(Coming soon)
My Audio Equipment Collection
Below is a sampling of the audio gear in my collection.
All components designated below as
AMB
brand are designed and built by myself.
A high quality analog turntable still feature prominently in each of my
systems because there is a certain magic
in a good quality analog LP and many of my record albums are
not available on CD. I built
my own turntable and
I also have the ne plus ultra
of analog cassette deck technology: the
Nakamichi Dragon and
Nakamichi CR-7A.
Contrary to what some might think, audio technology has not advanced
all that much in the past couple of decades, and some of the famed old
gear can still stand head and shoulders above much of the new stuff.
This is the reason why I still have several classic pieces
in my collection.
For the systems listed below, click on the lightbulb icon
[]
to see further details about each component.
Source Components
A broad mix of old and new, featuring several analog turntables,
cassette decks, CD player and Wifi network music player with
separate DAC, and high performance computer sound interfaces.
I had been an avid speaker builder for some time, thus the only piece
in my collection that isn't DIY is the Sunfire subwoofer and the
Velodyne subwoofer management system.
These are the key components integrating my home computer and LAN with
the music systems. All music files are encoded either in FLAC or
Ogg Vorbis formats.
Logitech
Squeezebox Server software, running on
openSUSE
Linux server
(for the Squeezebox 3 network music player and
SoftSqueeze
software players on other computers in the in-home network)
All music on the iPod are encoded either in FLAC or Ogg Vorbis format
(same content as on the Squeezebox Server at home),
playable only with the Rockbox firmware running on the iPod.
Apple
iPod Video 5.5G 80GB black, modified to 120GB with a Samsung HS122JB
disk drive, running
Rockbox firmware
Sony Discman portable CD player with ESP
Sony Walkman portable cassette player with FM/AM tuner
Mobile Audio
This is the system found in my Audi S4 biturbo quattro. All music
encoded either in FLAC or Ogg Vorbis format (same content as
on the Squeezebox Server at home).
PhatNoise
Car Audio System with PhatBox and 80GB DMS
(Audi version, interfaces with Audi Symphony radio)
Cables
Cables are a necessary evil. The best cable would be no cable at all,
but that is not feasible especially in a high-end system where there
are many separate components. On the other hand, I do not believe in
the snake oil and voodoo magic touted by many premium cable
brands to justify their lofty prices. To that end, I use all home-built
cables for component interconnect, and put good quality connectors on
the ends.
For audio interconnects, I use
Belden
8451 or 9452 dual conductor BelfoilTM
shielded cables. The shield wire is connected to the "ground"
conductor on the output end only, which means that the cable is directional.
The choice of these cables is for their superior shielding characteristics
and excellent sound.
For digital coaxial and composite video interconnects, I use
Belden 9221 or 8216 shielded coaxial cables. These cables are
characterized by very low capacitance and is thus suitable for use
in high frequency applications. I also use these cables as audio
interconnects where long runs are a necessity and where induced noise
interference is not a major problem.
All of these Belden cables I use are slim and flexible, making cable
routing very easy. In addition, they all feature very thin stranded
copper conductors. I am very pleased with their performance as used
in my system and I don't think high-end cables costing 100 times as
much as I spent on these would offer any further advantage.
For speaker cables, I use
Monster Cable
products. I believe that minimizing the cable impedance (and maintaining
a high effective amplifier damping factor) is of paramount importance.
The heavy gauge Monster Cables, with their copious thin strands and
flexible jacket fit the bill nicely. All my speakers and amplifiers
use gold plated banana plug connectors, which offer good contact surface
area as well as being easy to plug/unplug.
Power Surge Suppression, Line Filtering & Outage Protection
Each system is connected to the AC mains via high quality outlet strips
with surge suppression and overload protection breaker. In addition,
System 1 uses a NewPoint 2030 Joule AC/cable/phone surge suppressor and
AC line filter unit. The System 3 computers are protected by
APC
Back UPS 650 and Back UPS 600 uninterruptable power supplies.
Audio Accessories and Test Equipment
Here are some of the audio accessories and a sampling of
the various test equipment I use.