Ti Kan: Hi-fi Audio Multimedia

My recent DIY audio projects (that you could build too!):

The β24 fully-differential stereo power amplifier The β24 fully-differential stereo power amplifier γ3 DAC AMB γ3 high resolution DAC
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.

γ3: A high-end, high resolution desktop DAC designed to deliver extraordinary performance and features. Asynchronous USB, full complement of coax, optical and AES/EBU digital inputs and outputs. Full galvanic isolation on all inputs, selectable upsampling, dual-differential DACs, fully-differential analog output stage, with balanced and unbalanced analog outputs. Three high performance regulated power supplies with additional low noise local regulation throughout. Handheld remote control of all functions with LCD front panel display, and much more.

The α10 line pre-amplifier The β22 stereo amplifier and σ22 power supply The M³ stereo headphone amplifier The Cavalli-Kan Kumisa III stereo headphone amplifier
α10: A reference implementation of a high performance stereo pre-amplifier with precision relay-based stepped attenuator volume control and relay-based input/output selector. Handheld remote control of all functions with LCD front panel display, and many more features.

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.

: Three-channels of pure class A MOSFET power and exquisite sound. Maybe you could build one for yourself 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 Mini³ portable stereo headphone amplifier γ1 DAC γ2 DAC AMB γ1.5 miniature high resolution USB DAC + headphone amplifier
Mini³: Miniature in size and cost, but big in performance. This amplifier is rocking the DIY portable headphone amplifier scene.

γ1: A full-featured miniature DAC that's proven to be a superb companion for the Mini³.

γ2: A compact high performance upsampling DAC upgrades the γ1 and its modular concept deep into the high-end without the high cost.

γ1.5: A miniature 24/192KHz USB DAC with built-in headphone amp - uncompromising high resolution computer audio made easy.


Also see the σ11 and σ22 power supplies.

About Me

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.

Audio Stuff & Events

AMB DIY audio website - Resources for the DIY audio enthusiast.
AMB audio shop - Offering some parts for DIY audio projects.
Epique CBT36 by Dayton Audio curved line source array speaker system - My build log.
2016 San Jose headphones meet - Headphones and gear enthusiasts meet in San Jose on November 24, 2016 in San Jose, California.
2017 Burning Amp Festival - A gathering of DIY audio enthusiasts on November 12, 2017 in San Francisco, California.
2016 Burning Amp Festival - A gathering of DIY audio enthusiasts on November 13, 2016 in San Francisco, California.
2015 Burning Amp Festival - A gathering of DIY audio enthusiasts on October 17, 2015 in Redwood City, California.
San Francisco Head-fi Meet in Burlingame, California July 18, 2015.
San Francisco Head-fi Meet in Burlingame, California July 19, 2014.
2014 San Francisco Bay Area Heaphone Meet - San Francisco Bay Area headphone meet on February 16, 2014 in Redwood City, California.
2013 Burning Amp Festival - A gathering of DIY audio enthusiasts on October 6, 2013 in San Francisco, California.
2013 California Heaphone Audio N Gear fest - San Francisco Bay Area headphone/audiophile meet on February 17, 2013 in Redwood City, California.
2012 Burning Amp Festival - A gathering of DIY audio enthusiasts on October 28, 2012 in San Francisco, California.
NorCal/SF Bay Area Head-fi Meet in Burlingame, California Feb 11, 2012.
2011 Burning Amp Festival - A gathering of DIY audio enthusiasts on October 1, 2011 in San Francisco, California.
South Bay Mini-meet in Monte Sereno, California Mar 26, 2011.
NorCal/SF Bay Area Head-fi Meet in Burlingame, California Feb 19, 2011.
2010 Burning Amp Festival - A gathering of DIY audio enthusiasts on October 30, 2010 in San Francisco, California.
NorCal/SF Bay Area Head-fi Meet in Burlingame, California Feb 27, 2010.
2009 Burning Amp Festival - A gathering of DIY audio enthusiasts on October 18, 2009 in Sausalito, California.
NorCal/SF Bay Area Head-fi Meet in Burlingame, California Aug 8, 2009.
CanJam 2009 - International Head-fi Meet in Los Angeles, California May 30-31, 2009.
2008 Burning Amp Festival - A gathering of DIY audio enthusiasts on October 19, 2008 in Sausalito, California.
Let's build krmathis a beta22! - A community-donated group-build 4-channel β22 with dual σ22 power supplies.
NorCal Head-fi Meet - A gathering of headphone enthusiasts on June 28, 2008.
NorCal Head-fi Meet - A gathering of headphone enthusiasts on August 25, 2007.
Headfest 2007 - International Head-fi Meet in San Jose, California April 21-22, 2007.
San Francisco Bay Area Head-fi Meet - A gathering of headphone enthusiasts on February 25, 2006.
San Jose California Head-fi Meet - A gathering of headphone enthusiasts on August 6, 2005.
San Mateo California Head-fi Meet - A gathering of headphone enthusiasts on February 26, 2005.
San Jose California Head-fi Meet - A gathering of headphone enthusiasts on June 13, 2004.
San Francisco Bay Area NakFest - A gathering of local Nakamichi enthusiasts on March 13, 2004.
Go to my Links page for more audio-related links.

AMB Open Projects

Professionally manufactured PCBs and related parts are available via AMB audio shop:
α10 - high performance stereo pre-amplifier integrating the α20 line stage, LCDuino-1 display I/O processor, δ1 volume attenuator, δ2 input/output selector, σ22 regulated power supply and σ25 power supply.
α20 - all-discrete, fully-complementary versatile line stage amplifier/buffer.
α24 - fully-differential line amplifier for use as a pre-amp line stage, voltage DAC analog output stage/LPF, and balanced/unbalanced converter.
β24 - reference-class all-discrete, fully-complementary, cascoded, fully-differential power amplifier.
β22 - reference-class all-discrete, fully-complementary, cascoded, pure class A headphone amplifier.
- opamp-MOSFET pure class A headphone amplifier.
Cavalli-Kan Kumisa III - all-discrete, fully complementary, non global NFB headphone amplifier, originally designed by Benny Jørgensen and modified by Alex Cavalli and myself.
Mini³ - small portable headphone amplifier offering big performance.
χ1 - optional companion battery management board for Mini³ to use LiPo battery packs.
γ1 - full-featured, modular, miniature DAC.
γ1.5 - miniature high resolution asynchronous USB DAC + headphone amplifier.
γ2 - compact, high-performance DAC.
γ3 - no compromise high-end, high resolution desktop DAC.
σ22 - high performance, all-discrete, fully complementary, dual-rail, tracking regulated power supply.
σ11 - high performance, all-discrete, single-rail, regulated power supply.
σ25 - simple regulated power supply.
ε24 - power switch driver circuit with thermal sensing/shutdown feature.
ε12 - muting delay and DC offset protection circuit for headphone amplifiers.
LCDuino-1 - LCD I/O processor platform for audio and other control applications.
δ1 - relay-based precision stereo volume attenuator, part of the LCDuino-1 system.
δ2 - relay-based input/output selector, part of the LCDuino-1 system.
σ78 and σ79 - ultra low noise, high PSRR 1A voltage regulators - upgrade for 78xx and 79xx series
κDCX - upgrade analog board for the Behringer DCX2496 and DCX2496LE loudspeaker management system.
ο1 - ultra low jitter, low phase noise master clock circuit - upgrade for digital audio devices.
See the AMB DIY resources page for more.

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.

AMB θ6 speaker system AMB θ6W subwoofer close-up AMB θ6W subwoofer electronics AMB θ18 AMB θ19 AMB θ20
AMB α6 and β3 AMB α8 AMB α8 with cover open AMB β8 Various system components Nakamichi Dragon cassette deck
Nakamichi CR-7A Cassette Deck Pioneer RT-909 reel-to-reel tape deck Sunfire True Subwoofer Mk. II AMB λ1 turntable, Linn Basik Plus tone arm Systemdek IIX turntable, Linn Basik Plus tone arm Dynavector Karat 17D2 Mk.II cartridge
Ortofon Super OM-40 cartridge Hafler DH-120 and DH-220 power amps Hafler DH-100 series 2 pre-amplifier Benchmark DAC1 D/A convertor Audio Artistry CBT36 speaker system Velodyne SMS-1

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.
NAD C520 CD player, used as CD transport only
Logitech Squeezebox Touch network music player
Slim Devices Squeezebox 3 network music player
AMB γ1 miniature digital-to-analog converter with USB, S/PDIF coaxial and optical inputs
AMB γ1.5 miniature high resolution USB digital-to-analog converter with headphone amplifier
AMB γ2 compact high performance upsampling digital-to-analog converter
AMB γ3 high resolution upsampling dual-differential digital-to-analog converter
Benchmark DAC1 digital-to-analog converter
RME ADI-2 analog-to-digital and digital-to-analog converters
AMB λ1 turntable
Systemdek IIX turntable
CEC BD-5200 turntable (heavily modified), stock tone arm
Linn Basik Plus tone arm (two, one mounted on AMB λ1, another on Systemdek IIX)
Dynavector Karat-17D2 Mk.II moving-coil cartridge (mounted on AMB λ1)
Dynavector Karat 23R moving-coil cartridge (mounted on CEC BD-5200)
Ortofon OM-40 Gold moving-magnet cartridge (mounted on Systemdek IIX)
Nakamichi Dragon 3-head auto-reverse stereo cassette deck
Nakamichi CR-7A 3-head stereo cassette deck
Pioneer CT-F1250 3-head stereo cassette deck (two)
Kenwood KX-660HX stereo cassette deck
Pioneer RT-909 4-head 3 motor auto-reverse stereo reel-to-reel tape deck
Rotel RT-850A FM/AM tuner

Audio Processing

Equipment for audio processing.
Velodyne SMS-1 subwoofer management system
Behringer DCX2496 digital electronic crossover
dbx 224X tape noise reduction system
dbx 400X program route selector

Amplifiers

Lots of DIY amps, and a good collection of classic Hafler gear.
AMB α3 moving-coil pre-preamplifier
AMB α6 stereo pre-amplifier
AMB α8 stereo pre-amplifier
AMB α10 stereo pre-amplifier
AMB β3 stereo power amplifier
AMB β8 stereo power amplifier
AMB β24 fully-differential stereo power amplifier
AMB ε10 Line level summing amplifier
Sound Valves SV100 JFET stereo pre-amplifier
Hafler DH-100 Series 2 stereo pre-amplifier
Hafler DH-120 stereo power amplifier
Hafler DH-220 stereo power amplifier (two)
Dayton Audio DTA-1 "class-T" stereo amplifier (formerly Sonic Impact T-Amp)

Speakers

I had been an avid speaker builder for some time, thus the only piece in my collection that isn't DIY are the NHT speakers and the Sunfire subwoofers.
Audio Artistry CBT36K curved line-source array speaker system
AMB θ3W subwoofers
AMB θ6S satellite speaker system
AMB θ6W subwoofer (with integral electronic crossover and 100W negative output impedance amplifier)
AMB θ18 speaker system
AMB θ19 speaker system
AMB θ20 speaker system
NHT VT1 speaker system (factory prototypes)
Sunfire True Subwoofer Mk. II (with integral adjustable electronic crossover and 2700W tracking down-converter amplifier) (two)

Headphones and Headphone Amplifiers

This is an area where I've been spending a lot of time in.
Sennheiser HD800, HD600, HD580, PX100, HD410SL and HD50 headphones
The β22 stereo amplifier and σ22 power supply
The M³ stereo headphone amplifier
The Cavalli-Kan Kumisa III stereo headphone amplifier
The Mini³ portable stereo headphone amplifier
The Dynahi stereo headphone amplifier
AMB β18 stereo headphone amplifier
Millett Hybrid stereo headphone amplifier
σ11 linear regulated power supply
STEPS linear regulated power supply

Video

I am not a videophile, but I do watch Blu-Ray and DVD movies on occasion and these are more than nice enough for me as a 5.1 surround system.
Oppo BDP-83 Blu-Ray universal player
Rotel RSP-1068 Surround Sound Processor
Ölevia 242T-FHD 42" 1080p LCD flat-panel HDTV

Music Server

These are the key components integrating my home computer and LAN with the music systems. Most music files are encoded in FLAC format.
Logitech Squeezebox Server software, running on openSUSE Linux server (for the Squeezebox network music players and SoftSqueeze software players on other computers in the in-home network)
Linksys WRT54GSv4 wireless router, running DD-WRT firmware

Mobile Audio

This is the system found in my Audi S4 biturbo quattro. Most music encoded either in FLAC format (same content as on the Squeezebox Server at home).
PhatNoise Car Audio System with PhatBox and special 320GB 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.

Audio Accessories

Some audio accessories.
Decca 2+2 and Zero-ohms phono record brushes
Dynavector phono stylus brush
Discwasher SC-2 phono stylus cleaner system
Denon turntable bubble level
Radio Shack tape head demagnetizer

Test Equipment

Here are a sampling of the various test equipment I use.
Audio Precision System Two SYS-2322A Dual Domain audio analyzer, with options IMD and BUR, and filters FIL-AWT, FIL-CMS and FIL-CWT.
Nakamichi T-100 audio analyzer
Tektronix model TDS2014B 100MHz 4-channel color LCD digital storage oscilloscope
Protek model 6510 100MHz 2-channel analog cathode-ray oscilloscope
Fluke model 95 50MHz digital ScopeMeter
Wavetek 188 4MHz sweep function generator
Fluke model 187 true-RMS handheld digital multimeter
Fluke model 45 benchtop digital multimeter
Beckman HD100 digital multimeter
Circuit Specialists digital multimeter with transistor Hfe tester
Hewlett Packard 6236B 0-20V, 0.5A adjustable dual tracking / 0-6V 2.5A triple output benchtop power supply
Circuit Specialists CSI5003X5 0-50V, 0-3A / 5V 1A dual output benchtop power supply
Tangent Low Noise Measurement Preamplifier
RME ADI-2 analog-to-digital and digital-to-analog converters
E-MU 0404 USB 2.0 audio interface
M-Audio Firewire Audiophile audio interface
M-Audio Transit USB audio interface
Radio Shack sound pressure level meter
AMB headphone amplifier A/B comparison test switchbox
AMB headphone amplifier dummy load box (33Ω, 330Ω, or no load selector switch, ground-lift switch)

Misc Audio Projects Images

Building the AMB θ19 speaker system using Dynaudio drivers, and the AMB θ20 speakers using Audax and Fostex drivers.

Drivers and finished crossover network board The beautiful Dynaudio 15W75 Esotec 5" drivers, with 3" voice coil and die-cast frame Finished enclosures Finished system with grill
Finished system without grill AMB θ20 parts, with crossover already installed AMB θ20 finished, without grill AMB θ20, front and back


Me, the speaker-building wizard, back when I was only 18...

Me, the speaker-building wizard, back when I was only 18...


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Last update: 05/10/10 03:23:43