The Well-Tempered Computer, an introduction to computer audio

Saturday, April 30, 2011

Musiland MD30 DAC/Headphone amp

China's Musiland has gained quite a following especially in the headphone enthusiast circles.  Its MD10 is considered one of the best in terms of price/performance ratio.  Its new DAC/Headphone amp, the MD30 features USB2.0 high speed asynchronous interface at up to 32bit/192kHz.  At its core, a FPGA audio processing technology promise lower jitter and more accurate sound.  Also new is an asynchronous high-speed cache and DDS re-clocking scheme via is 1ps high precision programmable clock.  Its headphone section features "Energy Headphone Amp Level-III" technology provides a comprehensive headphone drive capability than competitors. 

1. Digital input:
  • USB 2.0 High Speed ​​Interface: 16, 24, 32Bit sampling depth up to 192kHz 
  • Coaxial RCA, BNC coaxial, fiber optic, AES: 16, 24Bit sampling depth up to 192kHz. Support MMDI instruction
  • MULINK high-definition digital interface (proprietary i2s): 16, 24, 32Bit sampling depth up to 192kHz. Support MMDI instruction.
  • Clock jitter (44.1kHz): S/PDIF less than 30PS, USB, MULINK less than 20PS
2. Line output
  • XLR balanced and RCA unbalanced
  • Dynamic range: greater than 120dB
  • SNR (A weighted): greater than 120dB
  • Total harmonic distortion: less than 0.0005%
  • Frequency Response (20Hz ~ 20KHz): +-0.2dB
  • Max Level: RCA Line 2V rms; XLR line 6V rms
  • Output Impedance: 10KΩ
3. Headphone output
  • Max Level: 4V rms
  • Impedance: 10Ω
  • Power: 260mW/RL = 300Ω

Focal The Bird 2.1

French loudspeaker specialist Focal's new The Bird 2.1 is compact system composed of mini two-way satellites connected to the “Power Bird,” which serves as a amplifier, 24-bit/192kHz upsampling DAC, and subwoofer in a single box. Supplied with a wireless dongle, Bird 2.1 interfaces with the Apple iPhone, iTouch, and iPad, providing uncompressed wireless audio. An optional USB dongle ($99.95) expands wireless connectivity to include any computer with a USB output. The user-friendly system includes a unified remote control and will accept a variety of analog and digital connections, both hardwired and wireless. The units can be positioned horizontally, vertically, or even mounted on a wall

  • High performance - utilizes Focal's world-class design and engineering leadership
  • Cutting edge -- uncompressed wireless audio, 24-bit /192kHz upsampling DAC, in a stylish subwoofer/electronics housing
  • Flexible - accepts wide array of analog and digital connections hard-wired and wireless. Can be positioned horizontally, vertically or even mounted on a wall.
  • User-Friendly - compact lifestyle design is stylish, simple to install and easy to operate
  • US$995

Friday, April 29, 2011

CI Audio VDC•9.0 and VDC•SB power supply upgrades

Channel Islands Audio's VDC•9.0 (US$279) is the perfect upgrade for Slim Devices/Logitech Squeezebox Duet, and the Wadia 170i/171i Transport. When used with either device, the upgrade eliminates noise caused by the standard switching supply, which can contaminate the internal digital and analog circuits.

The design utilizes a low noise/high current transformer, with discrete Schottky diode bridge rectifier, AC line filter, precision voltage regulator circuit, and 13,600uF of filter capacitance. Available in 120 or 240v input. Cables for Logitech Squeezebox Duet and Wadia 170 iTransport included.

Another version, the VDC•SB (US$259) is the 5v upgrade for Logitech Squeezebox Touch and the Classic SB3

Thursday, April 28, 2011

Firestone Audio ILTW 24/192 USB DAC

Firestone Audio's I Love Taiwan 24 Bit / 192 kHz Asynchronous-capable USB DAC delivers audiophile quality music via USB with performance capabilities up to 24 Bit /192 kHz.  At the heart of the ILTW is the highly regarded Wolfson's WM8740 DAC chip set with a host of other high quality components makes the ILTW DAC an outstanding value at just $367.

The ILTW DAC is capable of performing in both Adaptive and Asynchronous USB transfer modes with Adaptive as factory default setting.  An internal jumper setting switches between the two modes and Asynchronous mode requires special drivers.  Upsampling selectable to 96kHz or 192kHz.  Additional i2s over RJ-45 also provided.

Wednesday, April 27, 2011

M2Tech Young DAC photos

Got the M2Tech Young back with new board and firmware version.  Armed with new Mac OS X drivers.  We will post a review soon with comparisons with Calyx DAC 24/192, Weiss DAC 202, and Theta Compli Blu.

Tuesday, April 26, 2011

Light Harmonic DaVinci USB DAC

A new start-up, Light Harmonic's first product is the US$12,000 space-craft shaped USB DAC called the DaVinci which claims to be the world first "true" 384khz capable with best in-class technology, all discrete components, no negative feedback, fully balanced design. Its proprietary USB module is patent pending with a buffer layer to deal with jitters and controlled by a separate audio processor chip with 64-bit precision.  

We have seen other manufacturers quoting the 384kHz number but Light Harmonic points out that they are either non-asynchronous, requires proprietary drivers hence not true USB2.0 compliant, or in some cases resamples down to 192kHz before sending to the DAC chip.  

(We at digital audio blog has been beta testing a 32/384kHz firmware for XMOS-based asynchronous USB equipments with great results.  No need for custom drivers and the DAC chip is definitely 32bit/384kHz capable although XMOS does reduce resolution down to 24bits.  The Davinci DAC is also 32bit capable over USB.).  

There are some other engineering features, some of which are very interesting if proven:
  • Patent pending jitter-free three layer buffer asynchronous USB protocol
  • No drivers needed for Mac OSX
  • Duet Engine: analog interpolation to effectively doubling 44.1kHz sample rate using sophisticated aligned timing algorithm.  (Light Harmonics says that this is NOT over/up sampling nor noise shaping)
  • 3 x Clocks: one each for USB, 44.1k family and 48k family
  • 64-bit precision volume control
  • No "Ring" Architecture: Minimizes pre and post ringing
  • 8 discrete shunt regulators for digital, 2 nano volt regulators for clocks, 12 high precision regulators for USB module, 4 high current shunt regulators for analog
  • Option to disable low pass filter so no filters all the way to 100kHz when playing a 192k or 384kHz file where one does not have to worry about aliases and noises
  • 1 x USB 2.0 input
  • 1 x SPDIF input
  • 24-bit, up to 384kHz
  • SNR 111dB unweighted
  • Available Fall 2011
Real pictures here at Audiograb's coverage of Axpona 2011.

Monday, April 25, 2011

Aqvox USB 2 D/A MKII

German made Aqvox USB 2 D/A MkII is fully balanced USB 192kHz/24bit capable DAC with quite a unique set of features including USB input/output, defeatable asynchronous upsampling to 192kHz, integrated audiophile headphone amplifier.  The USB input/output is compatible with Windows98SE, Windows 2000, XP, Vista, Linux, Mac OS with included ASIO driver.

  • 4 x digital inputs: AES/EBU, Coaxial, Toslink and USB (USB1.1 48kHz/16bit without drivers, with optional USB2.0 upgrade - 192kHz/24bit with custom ASIO driver)
  • 2 x analog outputs: balanced XLR and unbalanced RCA
  • USB digital output (same port as input, up to 48kHz/16bit)
  • Selectable oversampling filters (32, 64, 128fs)
  • Dither on or off
  • Microphone input with integrated ADC to measure room acoustic (with accompanying software)
  • Audio file-formats: ALC, AiFF, FLAC, FLA, WAV, PCM, WavPack, SPDIF, via USB-ASIO, Monkeys Audio, AIF, Audio-CD, CDA, Apple Lossless, MPC, MP+, MPP, MP1, MP2, MP3, MP4 , LossyWAV, WMA, WMV, AU, OGG, AAC, MOV, AVI, AU, IFF, SVX, SND, AAC, APE, MAC, VOC, mp3PRO
  • No Op-Amps in signal path, Fully discrete, single-ended class A amplification, one amplifier per balanced analog output stage, true balanced circuitry for entire analog signal path
  • Headphone amplifier with fully discrete Class-A circuitry has no IC in signal path.  The headphone amp is coupled directly to the DAC chip, shortest signal path possible
  • No global overall feedback
  • LowNoise power supply
  • Dual Mono DAC chip (2 x Burr Brown PCM1796) 
  • USB-Codec: Texas-Instruments PCM2906 Transceiver
  • SPDIF digital input transceiver and sample rate converter for upsampling and jitter elimination AKM AK4114 192khz 24bit 
  • All functions are controlled with a programmed ATMEL Microcomputer chip set
  • Only passive elements are used in the filter-stages
  • Available in Black or Silver finish
  • US$1,799

Korg MR1000 mobile DSD recorder and AudioGate 2.0 software

For those interested in digital recording, Korg MR1000 mobile stereo DSD recorder is offered at a price  never before seen ($1,200) for such features and quality.

Future-proof Digital Recording
With the pristine fidelity, ultimate flexibility and advanced technology of a DSD recorder, the surprisingly affordable Korg MR-1000 is the stereo recorder that ensures your location recordings and final masters are never obsolete.

The mobile/tabletop MR-1000 delivers an astonishing 1-bit/5.6 MHz, doubling industry DSD recording quality standards. This new super-rate spec delivers a fidelity that will amaze even the most jaded audio enthusiast.

The MR-1000 is the perfect tool for the professional who wants to record and archive their final mixes in the studio, while its compact size and portability make it ideal for location recording, podcasting, live music performances - even for rehearsals and song-writing sessions.

After recording and editing all your tracks in the DAW/hardware system of your choice, you can mix directly, or via an analog summing mixer, to the stereo recorder. This gives you the superb fidelity of high-rate DSD technology, which preserves all the transients, nuances, and "air" from the original recording.

Powerful software bundled with this stereo recorder enables the conversion of your DSD recordings and mixes into all of today's audio formats without degradation. Best of all, by archiving your data/mix in this new double-speed 1-bit format you're ready for the future, as playback systems and standards change.

Real World Features in a Mobile and DSD Recorder
The MR-1000 can record to multiple formats, allowing you to choose the type that matches your needs. There are three ultra pristine, high definition 1-bit recording formats at your fingertips; DSDIFF, DSF, and WSD* (2.8224 MHz @ 1-bit or 5.6448 MHz @ 1-bit). In addition to the 1-bit recording options, multi-bit PCM formats (BWF or WAV) with resolutions up to 24-bit/192 kHz are also available. The MR-1000 can play back all of these file types and more, with the newly added MP3 playback feature. Various resolutions can be played back, including bit rates from 32 - 320 kbps, with a sampling frequency of either 44.1 kHz or 48 kHz. This gives you the added ability to store and listen to web ready MP3 files right on your stereo recorder. All of these functions make the MR-1000 a truly future proof tool that will be useful for recording all your endeavors in the years to come. It features a 40 GB internal hard drive, offering up to six hours of recording at the highest audio quality (1-bit 5.6448 MHz stereo), or approximately sixty hours at CD quality (16-bit 44.1 kHz).

The table-top MR-1000 location recorder includes combination XLR/ 1/4" input connectors with top quality microphone preamps, phantom power and built-in limiting. Both XLR and RCA outputs are provided for maximum flexibility.

High-speed USB 2.0 connectivity provides for fast and easy transfer of files between the recorder and your computer.

The MR-1000 can accommodate a total of 800 projects internally, and you can easily perform file management operations such as Rename, Delete, and Protect for individual songs. You can also register one hundred mark points in each song.

Designed for High Audio Quality
In order to deliver an unprecedented level of audio quality, careful attention was paid not only to the digital signal domain but also to the hardware design of this stereo DSD recorder. The input/output circuitry of the MR-1000 features ultra-high quality mic preamps. Power is supplied independently to the MR-1000's digital circuitry and analog circuitry, thus holding interference due to electrical current to an extremely low level.

Every component of the MR-1000 has been carefully selected to maximize performance. The respected Cirrus Logic CS4398 is used as the DAC (Digital/Analog Converter), and the Burr-Brown PCM4202 from Texas Instruments is used as the ADC (Analog/Digital Converter). By paying close attention to every component, the design has minimized any possible degradation of the audio signal.

Quality and Portability
The MR-1000 allows two-way operation; and this DSD stereo recorder can be powered by the included AC adaptor or by eight AA batteries, delivering 1-bit audio in a portable package that's equally at home in the studio or in the field. It comes with a specially-made carrying case that lets you record without removing the MR-1000 from the case, making it a great choice for field recording. The large backlit LCD display guarantees excellent visibility while, ensuring smooth workflow. The Almite-coated aluminum body provides strong impact resistance and stable operation in any situation.

1-bit Technology Equals Pristine Fidelity
1-bit recording is the latest advancement in audio, and has been adopted for use in the critically acclaimed SACD recording format. It offers a frequency response of DC to 100 kHz and dynamic range of 120 dB. This uncompromising fidelity, low noise floor, extended dynamic range, lifelike imaging and analog quality depth has been praised by top experts. But there are other important advantages to the format of this stereo recorder that are of benefit to all recording professionals, regardless of their tracking platform.

Future Proof Flexibility
Today's state-of-the-art 24-bit converters use high-speed 1-bit conversion to capture audio, using real-time decimation and other processes to present the data in the desired bit depth/sample rate format. The beauty of the MR's bitstream format is that it uses the original 1-bit data, without the need for the other processes. What comes in comes out, with no manipulation needed.

As files are converted and reconverted between various bit depths and sampling rates, there are possibly degrading effects, depending on the sample rate conversion algorithms. The critical issue is that files mixed and mastered in today's state of the art high-resolution audio may be insufficient for tomorrow's formats. Archiving your final mixes and masters in a 1-bit system allows you to bypass these issues, and preserve your music with both the highest fidelity and in a more "universal" format. That data then can more easily be converted at a later date to the bit depth/sample rate format of your choice without compromising the integrity or fidelity of the data. You can even convert to newer formats that will be adopted in the future, be they multi-bit or a further migration to the 1-bit format.

Korg’s free AudioGate 2.0 software is your bridge to translating your MR1000's DSD recordings into different file types; as well as to importing files from a variety of sources. 

For Version 2.0, you can now import and export in the following formats: WAV - BWF - AIFF - MP3 (export Windows only) - AAC (export Mac only, Flip4Mac WMV required) - Apple Lossless (export Mac only) - WMA (including WMA Professional and WMA Lossless – export Windows only) - DSDIFF - DSF - WSD.  AudioGate 2.0 also adds FLAC file support – the most popular lossless form of data compression.
DSF (DSD Stream File)
This is a DSD file format supported by some Sony "VAIO" personal computers (models with the "Sound Reality" engine) sold since September, 2005. This format is already supported by software such as "SonicStage Mastering StudioVer.2.0" and "DSD Direct," and it is expected that increasing numbers of software titles will support it in the future, including shareware and freeware. 
WSD (Wideband Single-bit Data)
This is a 1-bit audio file format created by the "One-bit Audio Consortium." It accommodates all formats of one-bit audio data without limitation of channel number or sample rate. The "One-bit Audio Consortium" was established in 2001 with the goal of contributing to the advance of audio through research, development, and popularization of 1-bit audio technology, and its work is currently supported by more than sixty members.
In addition to editing features like gain, fade, balance, and DC cut which AudioGate previously included, you’ve now got some new ones. “Normalize” automatically adjusts so that you can export files at their highest level without clipping. Plus, we’ve not only improved the output level range from ± 24 dB to ± 60 dB, but we’ve also expanded the peak level metering for better visual monitoring.

AudioGate 2.0 ensures that you get great-sounding results when you down-convert from one sample rate/bit depth to another. It now includes standard TPDF (Triangular Probability Density Function) dithering, plus Korg’s own enhanced “AQUA” dithering that closely follows human hearing characteristics for much more musical and natural sounding results.

You can use the tools listed above and now burn your own audio CDs, complete with CD-Text. But since you’re recording with an MR Series recorder, we know you are into the latest and highest quality technology out there. We’re right there with you. Now you can use AudioGate 2.0 to create DSD audio discs (1-bit/2.8 MHz) that preserve the superior audio fidelity that only 1-bit recording can deliver. You can play these enhanced discs in a variety of devices – Sony PlayStation, VAIO computers, and certain stand-alone DVD players.

Mac: AudioGate_v2.0.1

Windows: AudioGate_v2.0.1

Burmester Music Server 111

Berlin based Burmester Audiosysteme, founded in 1977, produces really high end stuffs. The legendary preamp 777 was indeed its foundation (named after its origination date – July 1977) and has established that shiny metallic look for all products that followed.  There are people who really like their stuff so much that they go out and buy a new Porsche, as Burmesters are premium sound system option for the car.  Of course, you need perfectly reproduced music to go with your Cayenne Turbo to pick up the kids.  

The new Music Server model 111 compliments their existing line of CD players (No 061, 069 and 089) and was launched during the high end show in Munich.  It is a hard disk based server with integrated drive slot for ripping, WIFI and LAN capable.

"The new Reference Line Music Server convinces not only by its excellent sound quality, but also by the extremely fast processing of even very large data sets. The local player is both about the device, via the web browser, and via handheld devices such as iPad with a specially developed Burmester Darfur app to be controlled.
Streaming over WLAN is also possible. On the integrated drive slot, an existing CD collection in the highest possible quality to rip it. Were not deposited album art and track information are added automatically to a comparison with the database. Due to the forward error correction (FEC) of only a few seconds for audio CD drives, there is the possibility that older or scratched CD went to an audio data stream that includes sporadic dropouts. Without appropriate countermeasures can thus reduce the noise listening."

Saturday, April 23, 2011

Weiss Medea+ and OP1-BP

Weiss's Medea+ flagship DAC's main changes are the new 32-bit ESS SABRE32 DAC chip, new output stage, integrated firewire input option, and glass fiber input option.  Weiss says existing Medea DAC can be upgraded to plus status.

The new OP1-BP output stage is interesting.  There is a general disapproval of operation amplifiers ("opamps"), but we just want to highlight that each integrated circuit ("IC") opamps out there are different, and then there are also discrete (non-IC) opamps.  In the Medea+, eight bi-polar discrete opamps are used for current to voltage function in the DAC's output stage.  

For those interested to tweak your own existing CD/DAC units, there is another discrete opamps that is available as after market direct replacements for IC opamps, the highly regarded Burson Audio's HD audio opamps.

Sforzato DST-01 Digital Stream Transport

And you think the Linn streamers are over the top? Extreme attention to detail, the Japanese made two-box Sforzato DST-01 upsampling Digital Stream Transport is a DLNA enabled streamer which connects to a Network Attached Server or PC over LAN network. Ultra-low jitter temperature controlled crystal oscillator to control the master clock.  Large toroidal transformers, with separate supply to digital processing and other circuits.  Each transformer is placed coaxially with leg spikes provide grounding of external vibration.  Front panel switch selects up-sampling rates of up to 192kHz with various digital filters settings (standard, no pre-echo, no post echo, minimum phase, etc.) which happens before sending digital signal to an outboard DAC.  Please note that the second box is the power supply, not the DAC. Sforzato is also developing a dedicated DAC for it which is going to be called the DSR-01 (DigitalStream Renderer).  Controls are done through iPod or iPhone using the included MLPlayer app.

  • Supported Files: AIFF, Apple lossless, FLAC, MP3, WMA Lossless, WAV
  • Sampling Frequency: 44.1k, 48k, 88.2k, 96k, 176.4k, 192k
  • Bit of support: 16bit, 24bit (Lossless WMA is 44.1k/16bit only)
  • Digital Output: AES/EBU, RCA (S / PDIF)
  • Word clock output: BNC × 1
  • Word clock input: BNC × 1
  • LAN: 100Base-T RJ45
  • Retail price: Yen 600,000 (approximately USD10,000)

Tuesday, April 19, 2011

Blacknote DSS 30 Tube Digital Streamer

Designed around an open source Linux platform, Blacknote's DSS 30 Tube Digital Static Streamer is capable of processing a wide range of audio format through external device connected via USB, with no moving parts inside.

  • Two front and three rear 2.0 USB ports, one of which dedicated to the computer only, one Ethernet port and one RS 232 serial port for LAN connection
  • Compatible with WAV, FLAC, AIFF, Apple Lossless, as well as commonly used compressed files such as MP3, M4A, AAC, etc. via USB Memory Sticks, Hard Disks, Computers and even CD Rom External Drive players having USB connection
  • All functions are managed by a customized Texas-Instruments microchip with future upgradability in mind
  • Power supply is via three dedicated customized transformers. The transformers supply power separately to the digital stage, the analog stage, and the output tube stage
  • DAC made by 24-bit AKM and Burr-Brown receiver chip
  • Tube analog output stage based on two 6922 valves with a balanced powered output

Resonessence Labs Invicta DAC

We predict that this will be the hot DAC of 2011.  British Columbia based Resonessence Labs's Mark Mallinson was former Operations Director for chip maker ESS Technology. Their design engineers and owners are DAC experts and were key in the design of the ESS Audio DAC, including the 9018 SABRE that is used in some of the world best (including our reference, the Weiss DAC202).

Their first product, Invicta, a stereo DAC, combination of careful audio, electrical and mechanical engineering. The Invicta supports many major audio inputs and outputs. Two headphone outputs along with an SD card reader. The back panel reveals a high speed asynchronous USB audio, Toslink, BNCs and AES/EBU inputs. 

All common sample rates are supported, and are displayed on the front panel. The analog outputs consist of both RCA and balanced XLR.  The Invicta uses a large OLED screen where audio source, volume, song selection, are displayed (for SD Card playback). 130dB signal to noise ratio (typical) and 0.0002% total harmonic distortion (typical) specs are up there with the best.  Solid engineering couples with deep digital know-how and good ergonomics should ensure that this will be a great unit.
  • ESS SABRE32 24/192kHz DAC chip with HyperStream technology
  • Digital filtering DSP and controls via Xilinx MicroBlaze FPGA soft processor cores
  • Ultra-low phase noise oscillator master clock
  • 1 x Toslink input and 1 x Toslink output
  • 2 x BNC digital input (with a firmware update at a later date can also be set to use as part of I2S transfer where three BNC connectors transmit word clock, Sdata, Sclk)
  • 1 x AES/EBU input
  • USB input (Cypress semiconductor based, 96kHz at the moment, USB 2.0 via firmware update)
  • HDMI video output (not yet in use, requires firmware update, for displaying tracks)
  • All digital inputs are transformer coupled, galvanically isolated
  • 2 x headphone outputs on front panel, simultaneous drive and levels can be independently set
  • SD card input on front panel (automatic play upon insertion, WAV format only, up to 24/192)
  • Low noise OLED screen
  • Firmware upgradeable (FPGA)
  • High quality AD797 J-FET operational amplifier output stage
  • Non-switching linear transformer power supply
  • Output: RCA: 2.4vRMS, XLR: 4.8vRMS
  • US$3,995

A compilation of asynchronous USB DACs

The Well-Tempered Computer is an excellent resource for all things Digital Audio.  Vincent Kars recently produced a good list of available DACs with asynchronous transfer mode, and an easy to understand measurement of Asynchronous vs Adaptive USB modes.

The site is filled with wealth of information and definitely one of the best reference out there for people who are putting together a Computer-As-Source audio system.  Highly recommended.

TC Audio Orbis

From Russia with love, the very elegant two-box CD transport + DAC (24/96 capable) - Orbis - from TC Audio.
  • Philips CD-PRO2LF mechanism with all metal loading tray
  • High quality clocks 
  • Digital inputs: AES/EBU and coaxial
  • Analog outputs: RCA and XLR
  • Dual mono construction, including proprietary link between transport and DAC 
  • Short path signal, all discrete elements and surface-mount PCB
  • Case machined from solid aluminum billet

Monday, April 18, 2011

Naim NDX network player

Compared to other established brands, Naim was a relatively late comer to the digital game.  But when they crossed over, they brought their analog amplifier experience with them.  Their first foray into digital music was in 1989 with the CDS-1 two-box player, considered one of the best in its time, and later its CD3 gained sort of a cult following.  

Zoom back to the 21st century, in addition to its  HDX hard disk player and Uniti all-in-one player, Naim has move on to the streaming player game with the NDX.  Think of it as a wireless DAC, the NDX plays UPnP audio streams, internet radio, iPod or iPhone audio, and files stored on USB memory hardware. Three high resolution S/PDIF digital inputs allow it to act as a stand alone DAC (up to 24 bit/192kHz resolution.)  Please note that it does not wirelessly play files on the iPod as it is not an Airplay compatible unit.
Its network connection can be either wireless (wifi) or wired (Ethernet LAN), and NDX can stream audio files, including from iTunes libraries, stored on a computer or on network storage, via UPnP. It can play all common audio file and stream formats at up to 24bit/96kHz resolution: WMA, MP3, MMS, AAC, Apple Lossless, WAV, FLAC, AIFF and Ogg Vorbis. The NDX also recognises M3U and PLS playlists formats and supports gap-less playback on all lossless formats.

NDX can also stream files from internet radio stations (optional FM/DAB tuner module available) and integrates seamlessly with the NDX control interface. NDX can play iPod or iPhone music via its front panel USB socket and, via the same socket, it can play audio files stored on USB memory sticks and drives. NDX is fully Apple-authenticated enabling playback of iPod/iPhone-stored digital media, bypassing the iPod/iPhone internal DAC for optimised performance.

All functions can be operated from its front panel buttons, from its remote control handset or using the Naim n-Stream iPhone app. The app also allows input and volume control of other Naim preamplifiers and DAC. 
The NDX uses a RAM buffer and master-clock jitter removal technique of the top-of-the-line Naim DAC outboard digital to analogue converter. The digital to analog conversion function is handled by a single Burr Brown DAC chip.  NDX uses an extruded non-magnetic aluminium case and chassis construction with extra attention to power supply noise and regulation is a fundamental element of its performance. A massive mains transformer, oversize smoothing capacitors, independent power supplies and multiple regulators, along with meticulous PCB layout and earthing topology, ensure minimal power supply noise.

Sunday, April 17, 2011

Record store day 2011

Line in front of Rough Trade East record store in Brick Lane, London on 16th of April, which the global record store day of 2011.  Hundreds were queuing up for special edition LPs and vinyl box sets.  Same line everywhere in front of participating independent record stores  such as Phonica and Sister Ray in Soho.  Vinyl is definitely alive and well in England.  Who needs digital?

TotalDac discrete ladder DAC

Once in a while something like Frenchman Vincent Brient's TotalDac comes along and leave us both intrigued and skeptical.  We are quite eager to hear it and see how it performs differently from mainstream DACs.  Its technical thesis sounds quite convincing: Vincent builds his own digital to analog converter module using discrete resistor ladders, not relying on off-the-shelf IC chips.  The only other commercial discrete DACs we know of are EMM's and MSB technology's.  See MSB's explanation of ladder DACs here.

From TotalDac website:
"I listened to industrial DAC chips (from Analog Device, TI, Philips, Cirrus Logic, Wolson, AKM...). Some of them were NOS chips known for their nice sound such as TDA1541, TDA1545 (used in CD723), TDA1543, PCM56, AD1852 (used in Teac VRDS 25x), CS4328 (used in Helios Stargate), PCM1702 used in many high end CD players in the past, PCM1704... Some were really nice but never very accurate. I listened to them with and without oversampling whenever possible. I used a Pacific Microsonic PDM100 HDCD digital filter, one of the best digital filter. I also listened to many new DAC chips from TI and Analog Device in particular. It required micro controller programming most times. The sound was often a bit metallic. Lastly I could listen to a discrete R2R DAC made of simple 1% resistors. Musicality was there but some accuracy was missing. This was the start point of my ultimate DAC. I spent 2 years and 5 revisions of PCB to improve it and finally use 0.01% Vishay foil resistors and other improvements in the FPGA. 
Jitter is very important for sound quality. It is related to the digital source and to the system clock. Today digital sources are sometimes computers so I wanted to make a DAC able to reduce the jitter of the source. An external clock is a common solution but it requires a digital source equipped with clock input, it exists but it is rare and specific. I wanted to make a DAC which can work with any digital source and any operating system and software when a computer is used. The only solution I could find is a solution rarely used, it is used only in some high end equipment based on FPGA and it uses a buffer memory (FIFO) to store about 0.1s of audio data at the digital source rhythm and output a stream at a local oscillator rhythm. At the beginning I used a low jitter crystal oscillator as a local oscillator. Of course there was a slight shift, as a consequence a crack appeared in the sound after a few hours. Practically this did not happen because the FIFO pointer was re-initialised between each CD track. The problem was elsewhere, I heard a kind of metallic sound when using these crystal oscillators. That's not surprising in fact because crystal are microphonic, there are even used to measure pressure. This problem disappeared when I used an RC oscillator instead but the RC oscillator frequency was not stable after hours. So I added a voltage control and the FPGA could control the RC oscillator frequency. A SPDIF receiver such as CS8412 or CS8416 already uses a voltage controlled oscillator but its command changes very quickly to track the input rhythm and so copies partially the jitter of the source. They have to track the digital source rapidly because they have a 80 nanosecond input to output delay whereas my DAC has a 10 mili second input to output delay"

The TotalDac is available both as a finish DAC or as a board which you can house our own.  A positive review from appeared last week.

Another well known DAC guru, Alexandre Cerqueira, is using a TotalDac board to create a active crossover/tube preamp. See his website:

Tone Audio issue 36

The excellent as usual Tone Audio online magazine issue 36 is out.  Unfortunately for us this issue is almost exclusively analog.

The magazine can be downloaded here. (22MB)

Wednesday, April 13, 2011

Fidelizer optimizes Windows for audiophiles

Fidelizer (v.1.4) will instantly turn your Windows Vista/7 computer to audiophile workstation for sophisticated audiophile player like J River, XXHighEnd, HQPlayer, foobar, etc. It involves no permanent modifications so system will remain safe and sound after restart so even system with normal Windows installation can experience better sound quality when needed. 

Why stopping services? Aren't my specs are good enough to handle them all?
Although you might have decent CPU, tons of RAM or even with SSD drive. However, these services are fighting each other to get processor resources and many of them relies on fixed hardware connections which have limited capacity to make solid performance. Stopping services will minimize work-load of svchost controllers, freeing more resources for allocation and improve system responsiveness. If stopping services sounds little too scary, you can skip this process as it's not the most important features after all.

It seems some features like stopping services are missing in this version. Are you trying to reduce features?
From what I've seen in concepts, I thought it should be 100% safe for any machine to use it. However, stopping most system services can cause unexpected problems in some machines. I got reports about Fidelizer breaking some applications and services, heavily slow down system because of recent updates in 1.2, etc. So I decided to take them off to ensure this program will 100% safe for yourself. However, I added something new that can be very effective in return and no one ever make it this far before too.

What does Fidelizer do in optimizing threads, I/O and random stuff like priorities and resources scheduling? Are they just made up for placebo effects?
Since Windows Vista, Microsoft introduced Multimedia Class Scheduler for thread and I/O priority optimization for processor resource scheduling. Most dedicated audio/video applications will benefit from this and it also affect overall system/network performance too. Default configuration are quite terribly optimized and not enough people going to take this feature serious enough to findout how I can get better sound through this. Fidelizer will do it for you without affecting real configuration so everything will still work fine after system restart.
I saw system thread priorities and clock resolution in another option. Aren't they the same to ones in resource scheduler?
Although Microsoft made pretty good resource management tool like that. However, it couldn't controll the whole system down to specific process and thread. This program will do additional works to ensure best sound reproduction with lowest possible latency in software and hardware I/O which can loosen up the continuity of bit-stream though it's performing bit-perfect. It'll enforce audio thread to highest level possible and reduce non-important processes and threads to lowest possible level for more throughput to audio thread. It also adjusts system clock resolution (NT Timer) down to lowest possible level for most accurate timing reference to improve stability of audio playback at lower latency.

I use DPC Latency Checker but Fidelizer doesn't improve system latency at all. Isn't it scam?
Graph in system latency shows latency of hardware I/O meaning you're checking hardware latency. Fidelizer will decrease software latency in operating system so DPC Latency Checker isn't capable of checking software latency. You need to test it with other methods. If you want to decrease hardware latency in DPC Latency Checker, try disabling drivers like networking for example.

If DPC Latency Checker is out of the game, how can I measure the difference in scientific way then?
You'd need high quality hardware and intensive measurement methods to make clear cut. Let's just believe in Microsoft that they didn't make stuff like Multimedia Class Scheduler just to fool pro audio market. If you're really desperate to do so, just try it with your ears, if you're unsatisfied or can't hear the difference, just delete it since it won't cause any changes to your system anyway.

TechDAS D-7 Precision Digital Interface

Stellavox Japan, a major audio distributor in Japan, has released its own line of product of which the TechDAS D-7 DAC, priced at approximately US$3,000 in Japan, would be the first of this new line. There will also be another version, the D-7i, which has direct iPod connections. 
The D-7 sports a Wolfson DAC chip (up to 24/192), and the galvanically isolated USB connection is of asynchronous type. Adjustable upsampling rate (1x, 2x, 4x) accessible from the front panel.  So via digital output, the unit can be used as an asynchronous USB to S/PDIF converter, and also asynchronous sample rate converter. Unit seems to be very well-made and styling is clearly influenced by Goldmund SRM models from the 1990s, of which the company has close relationship with.
  • Digital input RCA, Toslink, USB (up to 24/96)
  • USB host port for USB drives
  • RCA digital output
  • Word clock input
  • Fixed analog output (RCA and XLR)
  • Adjustable analog outputs (RCA)
  • Headphone amplifier
Future enhancements would include upgraded USB input to allow for 192kHz sample rate and possibly a LAN network support.

Tuesday, April 12, 2011

Tabla USB Interface

Hungary-based Human Audio's new Tabla USB 2.0 interface allows Mac or PC streaming up to 24bit/192kHz with coaxial digital output (BNC or RCA) for connection to DACs.  The device is battery-powered using two high-grade Lithium-Iron-Phosphate (LiFeSO4) cells. The charging is fully automatic and can also recharge USB power during idle.  Combination of super clean battery power, ultra-low jitter circuits, specialized pulse transformer and Human Audio's unique USB algorithm, promise great sound from this interesting looking unit.

Monday, April 11, 2011

Uber Muzik Tiny Tube DAC

Uber Muzik Tiny Tube DAC is a very cute tube buffered USB DAC/Preamp/Headphone amp.  It uses Psvane 12AT7 tube, and a separate TPA6120A2 chip for driving headphones up to 300ohms.  Resolution is limited to 24/48kHz but suggested retail price is only approximately US$200.