The Well-Tempered Computer, an introduction to computer audio

Tuesday, March 29, 2011

Berkeley Audio Design announces The Alpha USB Interface

Based on Gordon Rankin's Streamlength asynchronous USB transfer code, the new box converts USB into S/PDIF and outputs digital signal over 1 x RCA and  1 x AES/EBU.  It features a carefully designed power supply with a $1,695 expected retail price.

More details at

Berkeley Audio Design was founded by ex Pacific Microsonics veteran, most notably Michael “Pflash” Pflaumer, who co-headed the development of the HDCD process and the Pacific Microsonics Model Two, still considered one of the best professional ADC and DAC ever made.

The Berkeley Audio Design Alpha DAC was their first product and the new USB interface box is to bridge the gap between the excellent DAC and computer playback.

Monday, March 28, 2011

Sonore Music Server

The Sonore Music Server is a minimalist, Linux based computer audio playback system which rips CDs and DVDs, store audio data into a large internal storage drive with embedded tags and cover art. You can control playback of the stored audio content with any web browser on the home network, or with a free iTouch/iPhone/iPad/Droid App.  No screens, no keyboard.
  • Compatible with aiff, wav, flac, alac, mp3 and other popular formats without DRM
  • Control of music playback with a free iTouch/iPhone/iPad APP MPoD from Katoemba 
  • Control of music playback with web interface from any computer on the home network 
  • Automatic ripping and tagging of your CDs with cover art finder in flac format
  • Automatic ripping of your DVDs to MKV format
  • Includes solid state drive for operating system and 2TB harddrive for music storage
  • Shares and stores your music collection for use on the home network (iTunes compatible)
  • Fanless design
  • OPTIONS: Silver or black faceplate, 3TB hard drive for music storage

Lindemann USB DAC 24/192

The Lindemann USB-DAC 24/192 is a digital to analog converter which supports USB Audio Class 2 via special drivers for PCs (native on Macs).  The USB-DAC 24/192 features an additional, active jitter reduction circuit based on a digital PLL and memory buffering of the digital stream. The remaining overall jitter of the signal below 50ps. 

One particularly interesting feature is the use of "minimum phase apodizing digital filter" which replaces unnatural pre-ringing of traditional linear phase filter with a more natural impulse response - which eliminates pre-ringing and aliasing distortion, as well as reduces post-ringing.  This type of filter is based on Peter Craven's 2004 AES presentation and is currently used by a small group of digital audio manufacturers including Meridian, dCS  and Ayre (see white paper for more details.)  With the exception of Wolfson's WM874x chip family, apodizing filters are not standard in most of today's off-the-shelf DAC chips, so companies had to resort to customized DSP solution.  

While it does not say how exactly Lindemann executed digital filtering in the USB-DAC, but quoting from its top of the line 825 CD player "...To maximize resolution, the digital signal is processed by a Blackfin DSP. The code used is a Lindemann proprietary further development of the well-known Anagram Sonic 2.  In addition the original linear phase filter has been replaced with a much better sounding minimum phase filter with “apodizing behaviour”. This type of filter effectively suppresses time domain artefacts (including those present in the recording) by replacing the original impulse response with a new one with virtually no pre-ringing..."

The fully balanced, ultrafast output section with current feedback exhibits virtually perfect time domain behavior (But why no balance output?.) The output stage also features low negative feedback, the first-order analog filter and the lack of OpAmps.

Sunday, March 27, 2011

Classe CP-800 preamp/processor

Classe Audio of Canada recently announced a new stereo preamp/processor which seems to be the jack-of-all-trades. As a purist preamp, it has a pure analog pass-through that bypasses all the digital circuitry over its five analog inputs (2 x XLR, 3 x RCA).  For us digital buffs, there is also a DAC (using Wolfson WM8741 32-bit/192kHz chip), with asynchronous USB input (up to 24/96). For computer audiophiles, it can stream music via Ethernet with uPnP and DLNA protocols. For the kids, theres an iPod digital connection. There are of course the usual comprehensive digital inputs (coax, Toslink, AES/EBU) and also an HDMI 2-channel input. That's not all - it has parametric EQ, bass management with digital crossover, multi rooms, multiple outputs capabilities over its balanced and unbalanced outputs. It even has a dedicated headphone preamp for late nights. Available now for US$5,000 which is pretty darn good judging from everything it does along with its classy designs and seemingly excellent ergonomics.

The Classe CP-800 Stereo Preamplifier/Processor is said to be the first of a new generation of stereo preamplifiers designed to take full advantage of today's high resolution digital sources. The CP-800 offers new digital processing features including optimal asynchronous USB and full support of Apple's iPod®, iPhone® and iPad® range of products.  
In addition to accommodating legacy analog and digital sources, Classe announced that the CP-800 can also optimize playback from computer audio files and portable devices like iPods via USB using asynchronous techniques and proprietary clocking circuits. A storage device like an iPod or computer can contain all the data of the original recording, so it has the potential to be an audiophile source. The challenge is to clock that data into the D-to-A converters at precisely the right time, which the CP-800 achieves through newly-developed recovery and clocking technology.

A new power supply design optimizes the electrical environment for the audio circuitry inside the CP-800 and benefits associated equipment sharing the same AC power. PFC (Power Factor Correction) technology ensures the most efficient operation of the power supply while maintaining a constant load on the AC Mains. The benefit, according to Classe, is that the preamp/processor does not modulate the AC mains as would a conventional linear power supply without PFC. Other system components won't even know it's there.

In addition to superb performance as a digital-to-analog converter and stereo preamplifier, Classe says the CP-800 boasts features like bass management and parametric EQ that heretofore have been lacking in stereo preamps. There is a subwoofer output and two configurable auxiliary channels that can be used to drive additional subs, bi-amp the L&R channels or feed into another room.

Classe points out that a properly implemented subwoofer (or two) is at least as beneficial to stereo playback systems as it is to home theaters. Placing the Left and Right speakers for best stereo imaging rarely delivers ultimate bass response at the listening position, no matter how well those speakers can reproduce low frequencies. One or more subwoofers avoid this compromise. Parametric EQ enables further tweaking of the low frequency modes to achieve the best overall system performance. As with Classe SSPs, the subwoofer(s) may be configured for use with some inputs and not others or engaged with different crossover frequencies/slopes as desired.

An updated 16x9 touchscreen and graphical user interface give the CP-800 a fresh new look to match its advanced feature set.  

It didn't sound like that at the shop...

Free digital audio test tracks from Nuforce

These uncompressed WAV/FLAC/WMA/Apple Lossless format tracks may be freely download and distributed in its entirety only with attribution to Nuforce. The album art file must be included with the distribution.

Track list
  1. Drum Dynamics, 4608 Kbps / 96KHz.
    This track demonstrates a largely misunderstood term: dynamics. Any boombox can play loud. A good stereo’s dynamics range from feather-soft to thunder-clap loud. The metal and drums (skins and rims) reveal a system’s ability to convey lightning-swift transients.
  2. Cello Tonality, 4608 Kbps / 96KHz.
    Good stereo allows you to appreciate this 300-year-old cello’s unique timbre and rich resonance.
  3. Piano Tonality, 4608 Kbps / 96KHz
    This intimate yet remarkably powerful recording is especially revealing of the Fazioli piano’s percussive attacks, overtones and decays, and most especially, of its soul-stirring middle and lower range.
  4. Jazz Plucked Bass, 4608 Kbps / 96KHz
  5. Classical Plucked Bass, 4608 Kbps / 96KHz
    Apart from both instruments’ rich fundamentals and warm overtones, can you detect differences with respect to their individual character?
  6. Vocal Tonality, 4608 Kbps / 96KHz
    Her sibilants should have a natural rather than “spitty” character. You should also have a sense of the singer’s physical body – lips, tongue, throat, lungs and chest. The human voice via good stereo can be very seductive.
  7. Asian Flute, 4608 Kbps / 96KHz
    A brilliant yet distant, soulful and spacious sound, the result perhaps of applied reverberation?
  8. Binaural Tonality, 4608 Kbps / 96KHz
    You should experience a strong sense of left-right separation in an intimate setting yet with no sense of a hole in the middle of the soundstage.
  9. Complex Tonal Resolution, 4608 Kbps / 96KHz
    In contrast to the above, the flute and guitar appear to occupy the space between the speakers in yet another intimate setting.
  10. Outdoor Ambience, 4608 Kbps / 96KHz
    Does the band seem to be playing in an acoustically ideal space? – a well designed performance shell perhaps? Pay particular attention to location within the soundfield.
  11. Outdoor spaciousness, 4608 Kbps / 96KHz
    Have you a sense of the trumpets’ knife-edged brilliance playing into the open air?
  12. Harmonic Group Unity, 4608 Kbps / 96KHz
    Here we have an excellent example of a fully occupied, harmonically luxuriant soundfield. Our table in this jazz club isn’t very far from the band.
  13. Tonal Delicacy, 4608 Kbps / 96KHz
    Note the swift attacks and the harmonics they produce. Our proximity to the guitarist permits us to hear this beautiful instrument’s every intricate aspect.
  14. Complex Tonal Purity, 4608 Kbps / 96KHz
    Do you hear this performance as entirely natural or artificially enhanced? You should be getting better at this.
  15. Ensemble Power, 4608 Kbps / 96KHz
    A hard-driving performance you can almost feel in your chest. Does the band seem to be indoors or outdoors?
  16. Exotic Percussion, 4608 Kbps / 96KHz
    A perfect demonstration of sharp attacks, rich overtones, authoritative bass, and long, elegant fades into space.

Friday, March 25, 2011

Nuforce DAC-9 launched

Sneak previewed in our earlier post, the Nuforce Dac-9 has been launched.  The DAC-9's six digital inputs offer compatibility with all existing digital sources. Thanks to its defeatable volume control, the DAC-9 can be used without a preamp as a purely digital device (when switched to Fixed Output, the volume control circuit steps aside in order to provide a simpler, cleaner signal path.) 

An innovative output filter and minimalist analog output stage that requires no negative feedback permit the DAC-9 to preserve phase coherency and musical subtleties while simultaneously maintaining an excellent transient capability. The absence in the signal path of an oversampling filter and sample-rate conversion circuit further contribute to the DAC9's excellent performance characteristics. In addition, a toroidal transformer with multiple stages of voltage regulation provides tight, low-impedance power and should be able to drive any power amplifier directly.

The DAC-9's USB input supports 44.1, 48, 88.2, 96kHz 176.4, and 192kHz (Editor: correction. 192kHz option will be provided at a later date) from PCs and MACs.

For added convenience, the DAC9 includes a high-performance headphone output with independent volume control.

  • 6 inputs: USB, AES/EBU, RCA/BNC, RCA, toslink via 3.5mm mini Toslink optical
  • Outputs: Balanced XLR, un balanced RCA, 3.5mm and 6.3mm headphone output, the headphone output and optical input share the 3.5mm optical Input
  • Two ESS 9018 DAC chips working in current mode
  • Touch panel control
  • Digitally controlled defeatable analog volume
  • Remote control: volume, input select, dim, mute
  • Volume and sample rate display
  • List price US$1,695 
(April 13th 2011) More details on the DAC-9

  • Plug-in USB module/interfaces provide for upgradeability to higher bit rates
  • Minimal processing and the shortest possible signal paths
  • A pair of high-performance, non-over-sampling DACs offer up to 24-bit/192kHz (24bit/96kHz for USB) conversion of digital audio data. Extensive testing and listening tell us that up-sampling and sample-rate conversion do more harm than good, as does negative feedback. Consequently, no form of sample-rate conversion is ever employed. (Doesn't sound like 9018 to me??)
  • Summing the output of two DACs increases the signal-to-noise ratio to near-theoretical limits
  • An innovative Passive IV Digital Output Filter assures lifelike musical reproduction. The DAC-9’s passive circuit employs no negative feedback of any kind, thus providing a ripple-free response wherein high-frequency phase coherence is always maintained.
  • The converted signal passes on to the analog preamplifier stage, which also adheres minimalist design principles
  • Shunt-regulated linear power supply provides. With its multiple regulation stages, the power supply allows the DAC-9’s digital and analog circuits to operate to their fullest potential

Thursday, March 24, 2011

Chisto CD treatment products

Well...never say never until you really have tried it. We have tried all kinds of silver disc treatment products over the past two decades.  Green pens, disc demagnetizers, rubber mats, cleaners, etc. Some worked and some didn't. Let just say that the ones that do were like magic, which leaves you with "wow.." and then "...but how!?!".  We believe it's much to do with laser and reading errors where material science can actually reduce them, and produce a cleaner signal with better timing before feeding the digital to analog converter.  Remember, in music - timing is everything and errors just do not help.

Chisto is a specialist based in the Ukraine and we have been hearing good things about their Disk Analoguer and Black Analoguer.  Hifi-world magazine said "'s easy to use, treats a great many disks and using it can produce a smoother sound."   

We are planning to get a sample to try out, may be in a shoot-out of some sort.  Below are from their website...

  • Makes CDs sound analogue, DVDs show in full colors and sound, and absolute must for BLU-RAYs due to its data density. 
  • Application is simple. Spray from bottle on disk surface and wipe off with included Evolon® cloth until dry. 
  • Magic? No. Because even new disks are dirty and covered with MRA (Mould Release Agent) . So reading errors, so extra stress on your DAC, so digital artifacts and irritating sound. So simple. So big result. Your system become to sound more analogue. So strange... We still wonder. Try.

  • A perfect companion to the Disk Analoguer 
  • For application on the label side 
  • Reduces static charge and makes CD, SACD disks sound analogue, DVD show in full colors. 
  • Application is simple. Spray from bottle on label side and wipe off carefully with included Evolon® cloth until dry. 
  • Magic? No. Disk drive electronics are very sensitive and any small improvement here will benefit. 

Tuesday, March 22, 2011

Cambridge Audio NP30 network music player

Cambridge Audio’s new NP30 network music player streams music stored on any computer or network storage device enabling premium quality 24-bit playback across your home using your existing hi-fi or home entertainment system.

Using UPnP (the simplest way of sharing digital music files), the NP30 instantly connects to your home network with minimal set-up for instant access to of all your digitised music. But best of all, connection is completely wire-free since the NP30 supports all types of wi-fi networks including the latest N standard.

Add fast and easy access to a roster of over 20,000 trusted Internet radio stations, plus computer-free connectivity to your favourite music streaming services and you have a network music player to be reckoned with!

A breeze to use with its clear display, the NP30 can also be controlled using the amazing new free UuVol Remote App.
  • Simple no-hassle playback from any UPnP equipped laptop, notebook, PC, Mac or NAS hard drive
  • 24-bit/96kHz playback allowing the streaming of studio quality 24-bit WAV, AIFF, AAC, OGG Vorbis, MP3 and FLAC 
  • UuVol online music service enables fast and easy selection from over 20,000 Internet radio stations
  • Wolfson WM8728 DAC chip 24-bit/96kHz capable
  • S/PDIF coaxial and Toslink optical digital output

Monday, March 21, 2011

AMR CD-77 CD player / DAC

UK-based Abbingdon Music Research's CD-77 is probably the most advance and elaborate CD/DAC that is based on the vintage Philips TDA1541A chip, considered by some - the absolute best DAC chip ever made.  

The unit comes with several different sampling approaches from AMR's proprietary Digital Master non-over-sampling filter to oversampling to upsampling, which are user-selectable.  Digital Master I and Digital Master II were developed by AMR and are exclusive to the CD-77 and its brother CD-777.  

All internal clocks are synchronized to the exceptional military-grade temperature compensated master clock module to avoid the creation of unwanted beat frequencies, reduce overall digital noise and resultant jitter.  The CD-77's OptiReg® digital power supply circuit has 14 specifically designed regulators, most of which are two or three-stage. Its transport mechanism is an in-house design based on the high-precision, reliable Sony K-series laser pickup mated to the musical Phillips CD-18 servo system along with a proprietary high-torque direct-drive motor. This is all housed in a very substantial CNC machined aluminium CD well with an extra-stable CD spindle and a CNC machined aluminium CD clamp. 

CD-77's power supply transformers have been designed in-house and are individually hand-made. They are some of the most advanced double C-Core transformers available. AMR claims that they surpass even the impressive R-Core transformers used in many high-end components and comprehensively outclass traditional EI and toroidal transformers used in many peer group products. 

Other high quality parts including Ultra High Speed RF, military-grade design printed circuit boards, German-made premium film capacitors, AMR's own power supply polypropylene film Music Capacitors, zero noise schottky rectifiers and FEP Teflon insulated cable with silver-plate copper conductors for chassis wiring.

OptiBus® USB digital input accesses the vast library of music from a computer, allowing it to be enjoyed to a far higher level than conventional personal computer audio systems.  OptiValve® analogue stage is a thermionic electron valve circuit. Using no negative feedback, with high gain, very low distortion and low output impedance together with new old stock thermionic electron tubes.


Operation modes: 

  • Direct Master I; no digital or analogue filter
  • Direct Master II; no digital filter, anti-sin(x)/(x) analogue filter
  • Oversampling 2X, 4x
  • Upsampling 96KHz, 192KHz ( I am at a loss to understand why, since TDA1541 only does 16-bit/44kHz TDA1541A can accept sampling rates of up to 192kHz - 8x oversampling from 48kHz base data - without problems, albeit at 16bits resolution)
Digital Audio Inputs: 
  • 1 x USB interface, 1 X S/P-DIF Interface (optional)
Analog Outputs: 
  • 1 x RCA; 1 x XLR per channel
Digital Outputs:: 
  • 1 X S/P-DIF Interface (optional)
Thermionic Electron Valves: 
  • ECC81/12AT7 (NOS): amplification stage
  • 5687/6900 (NOS): output buffer stage
  • EZ80/6CA4 (NOS): rectifier stage

How about the price? If you have to ask - you probably can't afford it.

Saturday, March 19, 2011

Bladelius USB DAC

Swedish Bladelius Design Group, makers of ultra high end and stylish audio equipment, is launching a smallish and competitively priced USB-only DAC (rumored to be priced around $500).
Photo credit:
Key features

  • Up to 24-bit/192kHz (Burr-brown DAC chip)
  • Asynchronous USB transfer
  • Low jitter crystal osciallator
  • Powered by USB bus
  • Galvanic isolation between USB and analog circuits
  • Super low noise power supply with mutistage regulation and filtering
  • Low order modulator to filter out of band noise
  • Minimum phase (low pre-ringing) digital filter 
  • High power analog output stage via high quality RCA outputs

ESI U24 XL portable DAC/ADC and USB converter

ESI Audio's U24 XL is an extremely small (10cm x 9cm) and portable audio device offering total flexibility of an external USB device and pure digital quality, coupled with true high quality 24-bit support on the 2 analog input and 2 analog output channels.


  • 2 x analog input and 2 analog output channels (1/4" TRS connectors)
  • one output connector usable as headphone output
  • S/PDIF digital in and out available via optical (Toslink) and coaxial (RCA) connectors
  • 24 Bit AD/DA converter
  • realtime input monitoring for incoming signals
  • drivers for Windows 7/Vista/XP with ASIO support with low latency
  • Core Audio support under Mac OS X 10.4 and higher
  • dimensions: around 10 cm x 9 cm
  • bundled with Steinberg Cubase LE 4 for PC and Mac
  • US$179 list ($130 street)

Friday, March 18, 2011

Hegel HD20 DAC and HD2 USB DAC

HD20 is Hegel of Norway's new top of the line DAC. It offers both USB inputs as well as regular coaxial and optical spdif inputs and incorporates jitter reducing and impedance matching technology.

With the remote control (supplied) you can switch between the different inputs, dim the display or adjust the volume level. The HD20 has a high performance digital pre amplifier, fully capable of driving a high end power amplifier.

A rather unique functionality in the HD20 is that you are able to remote control computers that are connected to the USB port. If you start a play list you can use the HD20's remote control to start/pause and browse around in your play list. No installation is necessary, and it works on both PC, MAC and most different types of media players. Including most streaming services like Spotify or Rhapsody.

The HD20 has a high resolution 24 bit / 192 kHz D/A-Converter inside, and can play native 192 kHz from it's coaxial and optical inputs. It also has the capability to stream high definition 24 bit / 96 kHz audio files over USB.

  • 24bit / 192 kHz multilevel sigma-delta DAC
  • Signal output: 2,5V RMS
  • Digital inputs: 1 x USB, 2 x coaxial and 1 x optical spif
  • Line outputs: 1 pair of RCA unbalanced, 1 pair of XLR balanced
  • Frequency response: 0 Hz to 50 KHz
  • Phase response: Linear Phase Analogue filter
  • Noise floor: Minus 140 dB
  • Distortion: Typical 0,0007%
  • Power supply: Built-in torodial transformer, 30.000 uF capacitors
  • Dimensions/weight: 6cm * 21cm * 26 cm (H*W*D), 2,8 Kg
  • US$2,000
Hegel also offers a USB-only strip-down version which is the $350 HD2. Same underlying technology but with a 24/96 USB input with internal 24/192 (upsampled) and RCA analog output and a digital coaxial output - in case you use it as a stand-alone USB to SPDIF converter.

Thursday, March 17, 2011

Turtle Beach Micro II USB adapter

Turtle Beach's Audio Advantage Micro II USB sound card is the cheapest way ($25) to add a stereo analog and optical digital output to a Mac or PC.  The stereo output drives powered speakers, headphones or an external recording device. A built-in amplifier delivers crisp, clear sound on headphones or ear buds. 

The included mini Toslink optical jack adapter plugs into the mini headphone output and can output digital signal to DACs and digital capable home theater systems, digital speakers and other digital audio devices. This digital connection lets you enjoy DVD or streaming digital movies on your Mac or PC in high-quality, pure digital format.  
Mac users please note that newer Macs already output Toslink digital over its 3.5mm headphone output, so this product is geared towards PCs.
By installing an optional driver, the digital output can also send 5.1 channel Dolby® Digital or DTS™ surround sound as an encoded digital audio stream to your home theater system. (Only available on the Windows platform.)

Wadia W171i Transport

The original Wadia 170i transport was the industry’s first certified “works with iPod” dock to offer pure, bit-perfect digital output, allowing the iPod to perform as a high-end media server. Now the 171i is the first with a certified "works with iPhone".

“Our new 171iTransport does the neat trick of turning both the iPhone and the iPod into the ultimate media servers,” says John Schaffer, President, Wadia Digital. “Listeners who value high-end sound can get the full musical benefit out of their portable music collections, with all the storage advantages and the great user interface. It’s really the perfect marriage between convenience and performance.” 
High-resolution video signals are also passed cleanly through the dock’s component video connections. The cast aluminum chassis reduces unwanted resonance through its vibration absorbing isolation cones. A new power supply indicator is included as well.  A new feature-rich infrared remote control allows convenient navigation through Playlists and Albums. The 171iTransport will recharge either an iPhone or iPod when either device is docked to the iTransport.
"We taken the already amazing 170iTransport and improved its performance with the 171iTransport. We started by upgrading the internal power supply and circuit board. We improved the clocking for lower jitter. We added a TOSLINK digital output for DACs that do not have a coax digital input. The coax digital output was improved with an audiophile grade connector. There is also the new iPhone/iPad adaptor that allows for universal connectivity."

Wednesday, March 16, 2011

Aesthetix Pandora tube 24/192 DAC

Aesthetix's owner and cheif engineer Jim White was key designer/engineer of several legendary Theta Digital products back in the 1990s.  He then turned his passion to analog reproduction and created some of the best tube preamplifiers and phono stage of this decade.  Jim is now back to his roots by releasing two very promising digital audio products, The Pandora DAC and the Romulus CD player, promising analog sound from digital music.  The gorgeous Pandora tube DAC can do 24/192 (via flagship Burr-Brown PCM1792) with asynchronous USB input licensed from Wavelength.  Digital filter is proprietary using a separate DSP chip.  The tube output stage is no negative feedback with fully balanced configuration.  Judging from their electronics and analog reputation, these units are likely to sound stunning!

Pandora DAC's features:
  • Card-based DAC with three digital input slots.
  • AES/EBU, RCA Coax, Toslink standard on digital input 1 slot.
  • USB standard on digital input 2 slot.
  • USB capable of class 1 audio (96KHz, 24bit) and class 2 audio (192KHz, 24bit).
  • 2nd USB input optional.
  • Asynchronous transfer mode for USB input, licensed from Gordon Rankin / Wavelength Technologies.
  • Asynchronous transfer mode allows for jitter levels over a hundred times lower than previous USB solutions.
  • DSP based digital section using Motorola DSP56362 for digital filters.
  • DAC section based on Burr-Brown PCM1792A.
  • Analog section featuring four vacuum tubes in differential configuration.
  • Zero global feedback.
  • Balanced and single-ended outputs.
  • Volume control optional, allows DAC to drive a power amplifier directly. Switched resistor design.
  • Remote control of all functions.
  • Multiple stainless steel Faraday cages isolate critical digital, analog and power supply sections.
  • Two transformers, one for digital circuits and one for analog circuits.
  • All aluminum chassis construction.
  • RS232 control.
  • 12v trigger.
  • Unit Weight: 35 Lbs
  • Dimensions: 18" width x 4 3/8" height x 18" depth
  • US$5,000

Saturday, March 12, 2011

Furutech Alpha Design Labs GT40

Furutech, leader in performance cabling from Japan, electronics division Alpha Design Labs has launched the unique GT40 which is a high performance 24-bits/96kHz USB DAC plus a phono stage and headphone preamp.  The GT40 features a low-latency USB 2.0 audio driver that plays and records at 96 kHz. A likely first for this category, the GT40 includes a built-in low-noise MM / MC phono preamp, so you can record your favorite vinyl to hard disk via the USB output. 

  • High performance 96KHz/24bit USB DAC and ADC IC chip 
  • External power supply: while a USB-powered device might be convenient, it won’t develop the power required for high resolution playback
  • Headphone Amplifier: It contains a high performance headphone amplifier with ample drive for good headphones 
  • Analog-to-Digital Converter: The GT40 sports a high-performance ADC IC chip for high resolution recordings via analog inputs including phono, AM/FM radio, or other analog signals. 
  • Phono Preamplifier: A first for this class, the GT40 features a phono equalizer for recording your precious LPs. Switch between Moving Magnet (MM) and Moving Coil (MC) or Line input 
  • Highest Quality Parts: The GT40 features a high quality amplifier and condenser supporting its high performance analog circuit 
  • High End Audio Grade Connections: The GT40 is equipped with gold-plated Teflon-insulated RCA jacks with an extremely high quality aluminum chassis and machined volume knob

Thursday, March 10, 2011

Senior speakers

Northstar Design USB dac32

Italian-based Northstar Design is one of the first to offer true 32bit asynchronous USB high speed connectivity. Its USB dac32 has a full range of inputs including USB, coaxial, toslink, AES/EBU, and i2S (S/PDIF are handled up to 24-but 192kHz). Custom USB drivers for PC and MAC os X allows bit perfect transfers between the computer and the DAC. This incoming data are redirected to a FIFO memory and re-clocked with a high precision clock then to an asynchronous sample rate converter (Cirrus CSB421 chip) which upsamples all signal to 192kHz/32-bit. The digital section is completed by a pair of TI Burr-brown PCM 1795 converters in balanced mono configuration. There are two separate power supplies; one dedicated to the digital section and one dedicated to the analog section.

  • Hi-Speed USB2.0 192kHz-32bit digital input
  • COAX, TOSLINK, AES/EBU, I²S, USB digital inputs
  • Very low jitter 192/24 Cirrus CS8416 digital receiver
  • High stability on board master clock
  • Separated toroidal transformers for digital and analogue sections
  • Fully Balanced Analogue Stage
  • Analogue output on gold plated XLR an RCA

Wednesday, March 9, 2011

The Lampizator Transport

The legendary Lukasz Fikus just launched the new Lampizator Transport, full details on his website soon.

From what we know so far is that it is a transport based on the Logitech Squeezebox Duet and will be housed in the same chassis as the Lampizator DAC.  Lukasz built a new dedicated power supply and replaced stock capacitors with highest quality Oscons.  New MR superclock mk2 with its own transformer is installed. The key element that sets it apart from any other transport (well..except the stratospherically expensive Audio Note CDT Five, whose output stage is actually based on his design) is the Digilampizator buffered tube output stage, not for analog outputs since it does not have any, but for the digital S/PDIF output signal (Digital+Lampize+ator - get it?) 

The concept of Digilampization is quite refreshing.  We all know that a clean square wave signal with perfect timing is what needed from a transport. We spent time and money tweaking cables, re-clockers, isolation devices etc. to get closer to that.  Is there a better way?

From Lukasz' writing:

"....I analysed over 25 schematics and I reached the conclusion that all these player's digital trace and all schematics of outputs look bad. Some of them better than others, some - so-so, and some just plain bad.
What particularly annoyed me is that the signal trace is so sensitive to small changes of the load - resistance, capacitance and inductance. That's why digital cables sound different from one another - because the transmitter is not optimized. It is weak. Its output impedance is 10 times too high or even more.
if all the problems which distort the signal on the way to the DAC are arising from too weak generator, why not make what an engineer should and add a buffer. The chip will be happy working into virtually no load at all, just the grid. The square will be perfect as hell. Then the tube will have infinitely better output impedance (single hundreds of Ohms) and it will send the signal nice, pure, sharp , stiff and indifferent to cable and plugs. The quality means sending a proper signal not deploying voo-doo and mythology.

I took the tube which is good for high frequencies - the Russian 6N14P, which has a frequency response good till 200 MHz. Our signal needs circa 20 MHz bandwidth so the tube is ten times "too good" for the job. Any other radio tube is good, The parameters like amplification etc. do not matter because it is a cathode follower. The audio tubes are no good because the frequency range is too low.
Tapping of signal to output tube buffer  Credit:Lukasz Fikus
The resulting square wave is PERFECT. It beats the stock signal without sweat. The difference on the scope is night and day. There is no ringing, no roll off, all is just excellent. I have yet to see the output trace as clean as this one! The MR super clock also helps reducing jitter - data timing problems, as well as it eliminates the high frequency modulations of signals, power supplies and earth in the player...."
Before Digilampization  Credit: Lukasz Fikus
After Digilampization  Credit Lukasz Fikus
The LZ Transport's output tube also has a dedicated tube rectifier power supply. There is also provision for an i2s output in a proprietary arrangement (3 RCA outputs: clock, LRCK, and data). Music can be streamed via Wifi/LAN from any computer running Squeezecenter server software. There is also a memory buffer a-la Genesis Digital Lens, so that's even better.  The included Squeezebox Duet's remote has a screen which is highly usable from listening position.

All sounds very tempting.  Projected price is around EUR2,000.  Discussions about the new Lampizator transport over at Lampizator forum here.