With outstanding Hypex NCore Class D amplification and our class-leading StreamMagic music streaming platform onboard all you need to do is add speakers to enjoy superb high-resolution audio quality from one elegant, discreet box.
Power output 2*75W into 8 Ohms,Frequency response 20Hz – 20kHz
Simplicity meets performance - your complete audio solution in a single box
Stunning sound - the pure essence of over 50 years of hi-fi know-how
Optimised to bring the most from your favourite streaming services
Premium materials, timeless design - and customisable to suit your mood
Easy to set up, easy to use - elegant control app and high-resolution display
With Evo 150, we’ve brought your audio past and present into the future.
Rich dynamics, huge scale and complete control means inspiring sound
Compatible with every format, from vinyl to digital streaming and everything in between
Numerous digital and analogue inputs for wide-ranging system possibilities
Perfected to work with the widest range of speakers
Power Output 150W into 8 Ohms,Frequency Response 20Hz – 20kHz.
Because it’s designed to deliver the maximum musical experience no matter where the music is coming from, the CXA61 has an entirely reengineered digital board featuring the industry-standard ESS Sabre ES9010 K2M digital-to-analogue convertor.
60 Watts per channel with Class AB amplification for detailed and powerful audio performance
High Quality DAC - Connect digital sources directly via TOSLINK and Coaxial
Bluetooth aptX HD built in for a high quality wireless connection
4 x RCA Analogue connections for all your sources.
USB Audio Input accepting up to 32bit/384kHz & DSD 256 digital files from Mac or PC
The CXA81 is a complete solution. Its combination of versatility, power and audio excellence means it can form the centre of your musical experience for years to come.
80-watts per channel with Class AB amplification for detailed and powerful audio performance
Separate, symmetrical left and right channels are carefully engineered to deliver incredible sound-staging
Balanced XLR inputs for low noise interference,Bluetooth aptX HD built in
High Quality DAC - Connect digital sources directly via TOSLINK and Coaxial
USB Audio Input accepting up to 32bit/384kHz & DSD 256 digital files from Mac or PC
The CXA60 must be heard to be believed. Rated at 60 Watts per channel, its class AB amplifier design will reveal spectacular detail in your music. A low-flux toroidal transformer also enhances performance and together these design details deliver incredible control over your speakers.
To journey deeper into the music you love, the CXA80 has been designed from the ground up with built-in digital to analogue conversion capabilities. Using a high-specification 24-bit/192kHz WM8740 DAC chip from Wolfson.
The AM5 takes the blueprint of its little brother, the Topaz AM1, and then subtly refines it further. The pure sound quality and simplicity remain, as does the stunning value. But on top, there's more power and direct, easy input for smartphones and MP3 players.
Power output: | 25 Watts (into 8 Ohms) |
Frequency response: | (-3dB) 10Hz - 30kHz |
S/N ratio (ref 1w): | >82dB (unweighted) |
If you’re looking for an amp that never gets ruffled, the AM10 is what your ears have been waiting for. And with a genuine 35 watts per channel it gives some much more expensive competitors a serious run for their money!
35 Watts per channel |
5 x rear mounted source inputs |
1 x front MP3 line input |
Integrated phono stage for turntable connection |
The fully-featured SR10 combines a punchy integrated stereo amplifier with an FM/AM RDS tuner.
85 Watts per channel |
4 x rear mounted source inputs |
FM/AM RDS tuner with 30 presets |
1 x front input for iPod or MP3 |
Integrated phono stage for turntable connection |
Improving on such a highly regarded amplifier as its predecessor was never going to be easy. But by taking the award-winning 340A SE and adding some elements from the multi-award-winning 550A/650A platform, the new 350A is truly an amplifier to be reckoned with.
45 Watts RMS into 8 Ohms |
5 inputs, 1 Tape in, 1 Record Output |
Audiophile grade toroidal transformer and substantial extruded heatsink |
New precision ALPs ‘black box’ volume pot for improved low level channel balance and stereo imaging |
The new Azur 550A focuses on our most closely guarded principles – explosive sonic performance, incredible value and timeless design. Whatever music you’re into, we guarantee we’ve invested all our passion into making the very most of it.
Max power output per channel (Into 8Ω) 60W |
6 inputs, 2 outputs and tape In |
Oversize toroidal transformer and custom heatsink |
Revised output stage using new high current Sanken output transistors |
New Alps film type ‘black box’ volume pot for excellent channel balance |
The 351A offers a wide range of inputs so you can connect and enhance all your entertainment devices. Most importantly, we've developed a brand new USB audio input so you can directly connect your Mac or PC.
Power output: | 45W RMS into 8 Ohms |
THD (unweighted): | < 0.02% @ 1kHz, 80% of rated power < 0.15% 20Hz - 20kHz, 80% of rated power |
Inputs: | 5 x RCA, 1 x USB (type B), 1 x 3.5mm MP3 input |
Outputs: | Speakers A & B, 1 x Rec Out, ¼'' headphone out, |
USB | USB audio 1.0 16-bit 32kHz, 44.1kHz, 48kHz |
The new Azur 650A focuses on our most closely guarded principles – explosive sonic performance, incredible value and timeless design. Whatever music you’re into, we guarantee we’ve invested all our passion into making the very most of it.
Max power output per channel (Into 8Ω) 75W |
6 inputs, 2 outputs and tape In |
Twin rectifiers and separate power supplies |
Oversize toroidal transformer and custom heatsink |
Revised output stage using new high current Sanken output transistors |
So we listened to you and instead of adopting the more common and simpler approach of including USB connectivity on a CD player, we’ve developed a direct USB audio connection to the 651A amplifier. So now, you can simply plug your Mac or PC directly into the 651A amplifier and with the addition of your chosen speakers, you’ll instantly enjoy a whole world of digital music stored or streamed from your computer.
Power Output: 75 watts (into 8Ω)
Frequency Response: 5Hz - 50kHz (-1dB)
S/N ratio (ref 1w): >92dB (unweighted
Cambridge Audio continues to meet the needs of audiophiles at all levels and the 740A is no exception. The Azur 740A offers true hi-fi quality but at a fraction of the cost. Indeed the technology in the 740A is normally only used in products costing many times more.
100W RMS into 8 Ohms, 150W RMS into 4 Ohms |
6 inputs, 2 outputs and Tape In |
Customisable front panel display to allow assignable source inputs |
Incognito Ready™ connections to keypads and speakers for the simplest three-zone hub-less multi-room system |
When the Azur 840A was introduced it broke the mould by introducing an entirely new class of amplifier design in the shape of Class XD™ and marked the zenith of Cambridge Audio’s critically acclaimed Azur line-up.
Second generation proprietary Class XD technology |
120W per channel into 8 Ohms or 200W per channel into 4 Ohms |
Oversized low flux toroidal transformers |
Completely separate pre-amp and power amp toroidal transformers and circuits make the 840A effectively a pre and power amplifier combination in one chassis |
Sophisticated resistor ladder and relay based attenuator for extremely accurate volume/balance control |
Two pairs of very high current output transistors per channel in revised configuration for improved integration with Class XD |
The 840E is a high-end pre-amplifier which uses Cambridge Audio’s new proprietary Terrapin™ modules for unprecedented audio fidelity forming the perfect partner for the accompanying 840W power amplifier.
Terrapin™ amplifier modules designed and built by Cambridge Audio |
Sophisticated resistor ladder and relay based attenuator for volume/balance control |
Tone controls selected and individually stored by nameable input |
Balanced output to 840W power amplifier |
Input gain trims |
Quite literally in a class of its own, the new 851A Class XD integrated amplifier is designed to offer power, finesse and astonishingly low distortion. At its heart lies our own proprietary Class XD technology, which has been refined and enhanced since its inception in the 840 series, allowing even greater musical detail to be delivered to your speakers.
Power Output:
120W RMS into 8 Ohms
200W RMS into 4 Ohms
THD (unweighted):
< 0.001% 1 kHz at 80% of rated power
< 0.01% 20 Hz - 20 kHz at 80% of rated power
The 840W is a high-end power amplifier that has been designed by the same team behind the 840A and uses an evolution of Cambridge Audio’s hugely innovative Class XD™ technology for a highly detailed naturally musical performance.
Second generation Class XD™ technology |
Breathtaking 200W @ 8 Ohms and 500W into 8 Ohms bridged mono |
Two pairs of very high current output transistors per channel in revised configuration for improved integration with Class XD |
Twin rectifiers and separate transformer taps for dual mono operation of the left and right power amplifiers |
Oversized low flux toroidal transformer with an enormous 1200VA power rating |
Designed specifically for the new CX Series, the Cambridge CXC delivers stunning CD playback and works in perfect harmony with the Cambridge CXA60 and CXA80 integrated amplifiers, as well as other external DACs.At the heart of the CXC is our legendary ‘S3’ servo design.
So the Topaz CD5 does just one thing exceedingly well: getting every bit of music detail from your discs.Only music reproduction matters - and this audiophile CD player opens up a whole new world of real hi-fi sound, thanks to its premium components. What's more, it's designed play MP3s and WMA files from CD too, giving you flexibility where you want it, without compromising quality.
Digital to Analogue Converter | Wolfson Microelectronics WM8725 |
Filter | 2-pole Butterworth filter |
Supported disc formats: | CD-DA/CD-R/CD-RW/CD-ROM MP3/MP3 Pro/WMA |
Whilst an off-the-shelf CD/DVD-ROM drive might be fine for your computer, if you're really serious about extracting every last detail from your discs, you need a CD player that's been designed to do one thing only - to play audio CDs. The 351C is offers a real taste of audiophile purism - just without the price tag to go with it.
Digital to Analogue Converter | Wolfson Microelectronics WM8728 24-Bit/192kHz capable |
Filter | 2-Pole Sallen-Key Butterworth filter |
Frequency Response: | 20Hz – 20kHz |
THD @ 1Khz 0dBFs: | <0.003% |
IMD (19/20kHz) 0dBFs | <0.001% |
Linearity @ -90dBFs: | +/-0.5dB |
S/N ratio, A weighted | >99dB |
Stopband rejection (>24kHz): | >90dB |
With a highly regarded premium Wolfson Digital to Analogue Converter (DAC), a superior servo system and precision transport, the CD10 will harness every drop of information from your favourite discs and deliver uncompromised signals to your matching Topaz amplifier.
Wolfson 8761 DAC (Digital to Analogue Converter) |
CD, MP3 and WMA playback from suitably encoded discs |
Analogue and S/PDIF digital outputs |
Full remote control |
If you’re really serious about extracting every last detail from your discs then look no further than the 350C which features Cambridge Audio’s dedicated audio-only CD transport.
Completely new proprietary Cambridge Audio S3 servo solution |
Wolfson WM8728 DAC (Digital to Analogue Converter) |
All PCBs and DAC stages feature double-sided surface mount technology, eliminating wire inks and giving ultra short signal paths |
Highly accurate master clock oscillator and carefully designed impedance-matched clock buffering schemes |
The new 550C offers mind-bending performance from what at first appear to be a relatively modest design.
Audio specific S3 servo solution |
Double-sided surface mount circuitry |
Wolfson WM8740 DACs (Digital to analogue converters) - Single |
Three-Pole Double Virtual Earth Balanced filter topology |
CD-Text display for suitable discs |
Taking performance even higher, the 650C builds on the 550C by optimising a pair of WM8740 24bit/ 192kHzcapable DACs implemented in a dual differential configuration.
Audio specific S3 servo solution |
Double-sided surface mount circuitry |
Wolfson WM8740 DACs (Digital to analogue converters) - Twin |
Four-Pole Dual Differential Double Virtual Earth Balanced filter topology |
CD-Text display for suitable discs |
Developed to offer a true taste of high-end musical reproduction at an altogether more affordable price, it features an all-new twin Digital to Analogue Conversion system (DAC) with the same selectable filter arrangement used in the legendary DacMagic.
D/A Converters: Dual Wolfson Microelectronics
WM8742 24-bit/192kHz capable
Filter 2-Pole Dual Differential Bessel
Double Virtual Earth Balanced
Frequency Response: 20Hz - 20kHz (+/-0.1dB)
THD @ 1Khz 0dBFs: <0.003%
THD @ 1kHz -10dBFs: <0.0005%
The 740C is the latest in Cambridge Audio’s Azur series of CD players. Using the upsampling technology present in the top-of-the-range 840C barnstormer, now married to dual Wolfson WM8740 24-bit DACs with a newly developed Bessel implementation of our proprietary virtual earth balanced filtering, the 740C is set to rejuvenate the mid price sector. The 740C incorporates the same 32-bit DSP as the 840C and upsamples to full 24-bit 384 kHz
The 840C marks the zenith of Cambridge Audio’s critically acclaimed Azur line up. Like all Azur products, the 840C promises unseen levels of performance and engineering excellence to the price points in question. But rather than redefining expectations in the entry-level market, the arena most often associated with Cambridge Audio, the company will reinvigorate the mid-end price sector
The 851C is a staggeringly complex creation but one with a simple mission: to make your digitally stored music sound sublime. It’s a high-end CD player, a state-of-the-art DAC and digital preamp in one highly accomplished package. The 851C has been designed to operate at the very heart of your digital music system, offering incredible functionality and performance.
D/A Converters:
Dual Analog Devices
AD1955 24 bit DACs
Digital filter:
Analog Devices Black Fin
ADSP-BF532 32 bit DSP performing 2nd Generation ATF2 up-sampling to 24 bit 384kHz
The audiophile CD30 player features an entirely new servo transport solution providing the ultimate platform for which Cambridge Audio is renowned and shuns the DVD-ROM derived design commonplace in this category.
Wolfson WM8716 DAC for incredible detail and stereo imaging |
Automatically switches on when source is selected on receiver |
S/PDIF coaxial and Toslink digital outputs |
The AR30 FM/AM integrated 2.1 receiver proves Sonata’s beauty is way more than skin deep. Using a substantial toroidal transformer and fully discrete amplification, this svelte receiver offers genuine hi-fi performance.
40W per channel (8 Ohms) |
Dedicated iPod dock with quasi-differential noise cancelling technology which guarantees first class audio playback and auto-charge. Made for iPod Mini, iPod (4th, 5th generation), iPod Nano (1st, 2nd, 3rd, 4th generation), iPod classic, iPod touch (1st, 2nd generation). Compatible with: iPhone (flight mode recommended) |
FM/AM 2.1 receiver with RDS |
Front mounted MP3 in socket for other portable music devices |
The DR30 DAB/FM integrated 2.1 receiver proves Sonata’s beauty is way more than skin deep.
40W per channel (8 Ohms) |
DAB/FM 2.1 receiver |
Dedicated iPod dock with quasi-differential noise cancelling technology which guarantees first class audio playback and auto-charge Made for iPod Mini, iPod (4th, 5th generation), iPod Nano (1st, 2nd, 3rd, 4th generation), iPod classic, iPod touch (1st, 2nd generation). Compatible with: iPhone (flight mode recommended) |
Front mounted MP3 in socket for other portable music devices |
If you love your music, choosing a mini hi-fi system traditionally involves a significant compromise. Stylish all-in-one solutions can look great but ultimate performance and sound quality are all too often lacking.
Powerful 30 Watts per channel into 6 Ohms (25Wpc into 8 Ohms) featuring optional equalisation circuitry to enhance micro speaker set-ups |
Slot-loading CD player – MP3/WMA compatible |
Dedicated iPod dock provides audio playback and auto-charge. Made for iPod Mini, iPod (4th, 5th generation), iPod Nano (1st, 2nd, 3rd, 4th generation), iPod classic, iPod touch (1st, 2nd generation). Compatible with: iPhone (flight mode recommended) |
USB and SD card connections with two-line text feedback (artist, track) and dedicated source inputs |
DAB+/DAB (band III and L band)/FM tuner with RDS** |
The 351R amp delivers superb-quality surround sound, plus stunning audiophile stereo for brilliant music reproduction, at amazing value. Our designers have obsessed over the audio, creating surround sound that truly immerses you in big-screen action and music reproduction so good it will make the hairs on the back of your neck stand up.
70W RMS per channel, into 8 Ohms (two channels driven)
50W RMS per channel, 8 Ohms (all 5 channels driven
Cirrus Logic CS497024 Dual 32 Bit DSP for surround decoding
4 x HDMI (1.4a)
Power Output: All Channels : 110 watts rms per channel,
6 ohms (two channels driven)
THD: <0.006% @1kHz
Crosstalk: <-60dB @ 1kHz
Frequency Response: 10Hz - 20kHz -1dB
Signal to Noise Ratio: >90dB 'A' weighted
Audio input impedance/sensitivity 47kOhms / 175mV or greater
Finally, a home cinema receiver that will make your music sound as great as your movies. The Cambridge Audio Azur 651R is perfect for pumping out audiophile stereo and the biggest of big-screen surround sound action.For truly stunning home cinema, the 651R features top-end 7.1 outputs (with option to run twin subwoofers), dual Texas Instruments 32-bit DSPs to support the broadest range of surround formats and speaker layouts.
140W RMS per channel, into 8 ohms (two channels driven)
100W RMS per channel, into 8 ohms (all 7 channels driven)
Cirrus Logic CS52526 24-bit 192kHz capable CODEC for surround channels + 24-bit 2 channel
Two TI Aureus DA788 32-bit DSPs
The 751R's Anchor Bay ABT2010 scaler will coax 1080p Full HD detail out of even analogue video signals, but the amp also features a unique scaler bypass mode that improves picture quality by preventing "double-scaling" content that has already been upscaled externally .Detail from any audio source, from MP3s to high-end digital audio streams, can be boosted to up to 24-bit/192kHz better-than-CD-quality.
170W RMS per channel, into 8 ohms (two channels driven)
120W RMS per channel, into 8 ohms (all 7 channels driven)
Additional AD SP-21261 40-bit DSP performing 24bit/192kHz ATF Upsampling
Frequency response10Hz - 20kHz ±1dB
allows playback of multiple audio file-types from multiple sources. Enjoy your music, your way.
Stunning Sound Quality - Hear every detail in your digital files
Connect Anything - USB, Coaxial and TOSLINK wired connections. AirPlay 2 and Chromecast built-in wireless connections
Spotify Connect, TIDAL and Qobuz built in
High-quality Internet Radio Streaming thanks to MPEG-DASH support
Control in the palm of your hand, thanks to the dedicated StreamMagic app for iOS and Android
Roon Ready. Transform and enhance the experience of browsing your music.
Wherever your digital audio comes from, whatever format you store it in, the Stream Magic 6 network music player makes it sound stunning! From smartphones/tablets and laptops, to Blu-ray players, TVs and games consoles, and with support for audio streaming services including BBC iPlayer, Aupeo, and Pandora plus with access to over 20,000+ internet radio stations – the Stream Magic 6 doesn't just stream audio on to your hi-fi amp and speakers, but dramatically improves it as it does – bringing out the ultimate in detail, clarity and quality from your digital audio.
Digital to Analogue Converter | Dual Wolfson WM8740 24-bit DACs |
Digital filter: | 2nd Generation ATF2 up-sampling to 24-bit/384kHz. Linear Phase, Minimum phase or Steep modes. |
Analogue filter: | 2-Pole Dual Differential Bessel Double Virtual Earth Balanced |
However you experience digital music, the NP30 is waiting to show you how easy it is to unite all types of computer-based music in the most amazing quality ever.With the ability to playback 24-bit studio master quality files, the NP30 not only offers every digital music convenience feature, but delivers a better-than-CD experience too!
DAC | Wolfson WM8728 24-bit/96kHz capable |
THD+N | 0.003% @ 1kHz |
Frequency Response: | 20Hz-20kHz +/- 0.2dB |
Signal to Noise Ratio: | > 95dB |
Total correlated jitter: | <200pS |
Digital Outputs: | S/PDIF Co-axial and TOSLink Optical 16-24 Bits, 22.05-96kHz |
With five Min11 satellite speakers placed at the front, centre and rear of your room and a tiny X200 subwoofer located wherever you wish; this amazing system will instantly transform your living space into a private cinema.
Frequency Response: | 120Hz-20kHz |
Impedance: | 8 Ohms compatible |
Recommended amplifier power | 25 - 200W |
X200 subwoofer |
|
Power Output: | 200W |
Frequency Response: | 39Hz (-6dB) – 200Hz |
The science behind Minx is difficult to explain, but much of the magic comes courtesy of an intensive two-year development programme by Cambridge Audio’s engineers to achieve extraordinary sound from incredibly small cabinets.
Frequency Response: | 120Hz-20kHz |
Impedance: | 8 Ohms compatible |
Recommended amplifier power | 25 - 200W * |
X300 subwoofer |
|
Power Output: | 300W |
Frequency Response: | 33Hz (-6dB) – 200Hz |
The CXU is the pinnacle in high-end home cinema. Designed for the ultimate performance and playback of your favourite movies and music, the CXU has unrivalled connectivity making it a complete home cinema hub, whatever your source.
Video processor DARBEE Visual Presence
External storage 3 x USB 2.0
5 x Wolfson WM8740 24-bit/192kHz DACs
Network connection,S/P DIF audio input,Optical audio input
Azur 752BD Universal Upsampling Blu-ray, DVD & CD player.
Our best ever universal player gets the very most from video and audio discs, digital files and streaming.Its Marvell Qdeo video processor upscales any video source to Full HD and can perform realtime 2D-to-3D conversion. It can even upscale to 4K resolution, if your TV or projector supports this new ultra-high-definition format.
Analog Devices ADSP-21261 32 bit SHARC(R) DSP running Anagram Technologies (TM) Q5 up-sampling to 24 bit/192kHz (All 10 channels).
2 x 1.4a (one with MHL compatibility via the front panel)
5 x Wolfson WM8740 24bit DACs
If sound is as important to you as experiencing the ultimate in image definition, the all new 651BD is the 3D Blu-ray universal player you've been waiting for...
Video output 2 x HDMI 1.4a, component video, composite video
Audio Outputs: 7.1 multichannel analogue RCA/Phono output, SPDIF coaxial and Toslink optical digital outputs
D/A Converters: Cirrus Logic CS4382A 8 channel multi-DAC
Decoder Mediatek MTK8530
Video Scaler Marvell DE2750 QDEO Video Scaler (on primary output)
Internal memory 1GB (Actual available storage varies due to system usage)
With support for BD-3D, all the latest surround sound formats, QDEO video processing and Anagram Technologies audio up-sampling, the 751BD is a lightning-fast, easy to use player and is guaranteed to reproduce your movies and music with all the gusto of the original performance!
Decoder Mediatek MTK8530
Upsampler Analog Devices ADSP-21261 32 bit SHARC(R) DSP running Anagram Technologies(TM) Q5 up-sampling to 24 bit/192kHz (All 10 channels)
D/A Converters: 5 x Wolfson WM8740 24/192kHz Digital to Analog converters
Video Scaler Marvell DE2750 QDEO Video Scaler (on Primary output)
Internal memory 1GB (Actual available storage varies due to system usage)
Featuring DAB+ technology, the 651T means you can not only enjoy regular DAB stations but also reap the benefits of new DAB+ digital broadcasts in even higher quality thanks to support for the latest HE-AAC audio format.
Digital to Analogue Converter | Wolfson WM8740 24-bit DAC |
Frequency range: | FM (87.5-108MHz), AM (531-1620kHz) DAB Band 3 (175MHz to 240MHz) DAB L Band (1453MHz to 1491MHz) |
Aerial inputs: | 50 F-Type (DAB), 75 (FM), AM Loop |
Sensetivity: | 25dBm typical |
Featuring DAB+ technology, the 650T means you can not only enjoy regular DAB stations but also reap the benefits of new DAB+ digital broadcasts in even higher quality thanks to support for the latest HE-AAC audio format.
Brand new DAB+ capable module supporting AAC+/HE-AAC broadcasts (Band III and L Band) |
Separate true analogue FM/AM stage |
RDS/RBDS compatible FM |
Wolfson 8740 audiophile quality DAC (Digital to Analogue Converter) |
The multi award-winning DacMagic is the world’s most affordable and effective way to upgrade any PC, Mac, network music player, digital iPod dock, games console or any device with a Digital Audio out to truly high end sound quality.
D/A Converters: | Dual Wolfson WM8740 24bit DACs |
Digital filter: | Texas Instruments TMS 320VC5501 DSP upsampling to 24bit 192kHz |
Analogue filter: | 2-Pole Dual Differential Bessel Double Virtual Earth Balanced |
Improving on a legend is never easy, but Cambridge Audio has gone back to the drawing board to create the DacMagic Plus with exciting new features, wireless device connectivity, and best of all, significantly enhanced audio performance.
Twin Wolfson WM8740 24bit DACs used in dual differential configuration
New Anagram Technologies ATF2™ 24-bit/384kHz audio up-sampling / jitter reduction
Optional Digital Preamp mode allowing connection directly to power amp or active speakers
24-bit/96kHz driverless USB Audio 1.0
24-bit/192kHz USB Audio 2.0 with ASIO or kernel streaming modes
Asynchronous USB transfer for very low jitter