8 Everyday Practical Electronics, June 2018

data rates, around 10Mbps, which streaming services cannot cope with and would cost users on lim-ited data plans an arm and a leg to receive.

Online sites can already deliver near-CD quality as MP3 at its high-est data rate of 320kbps, but MP3 most definitely is lossy and perfor-mance can depend on the nature of the music.

MQA origamiMQA starts with 96/24 high-resolu-tion source material, and as a first step filters it into three frequency bands; DC to 24kHz, 24kHz to 48kHz, and 48kHz to 96kHz.

Everything in the 48-96kHz band is then ‘origami’ fold-ed into digital space below the 24-48kHz band.

The 24-48kHz band, and the em-bedded 48-96kHz band, are then ‘ori-gami’ packed into the DC-24kHz main band in the bottom 7

bits of the 24-bit words.So the bottom 7 bits (least-signifi-

cant bits, LSBs) of the 24-bit words now carry all audio data above 24kHz, and nothing else. The top 17 bits (most-significant bits, MSBs) carry ‘normal’ CD-quality audio.

The resultant 24-bit MQA ori-gami stream now has a data rate of around 1.1Mbps, which is regarded as manageable for online streaming. When this stream is played with a ‘normal’ 16-bit player, the player ignores the bottom 8 LSBs and uses the top 16 MSBs to give CD-quality frequency and dynamic range.

When the 24-bit MQA stream is played with an MQA decoder, it

Search under ‘MQA’ and you will find much highly technical argu-ment on all this – but little if any-thing that explains in simple, but factual, words how the ‘origami’ process actually works.

Reading the patents on MQA is of limited help because they describe a wide range of theoretical options.

And it’s in the interests of the MQA licensing body not to make things too easy for competitors or for crit-ics to pick holes in the system.

MQA basicsSo I talked with some industry in-siders and put together – if only for my own use and reference – an

idiot’s fact guide to what goes on in-side the MQA coder and decoder. I then put this to MQA for comment and correction. So far, I’ve not been corrected, but we can always add anything forthcoming as a future footnote.

CD-quality audio, known as ‘Red Book’ from the standards set in the 1980s by Philips and Sony, sam-ples analogue sound at 44.1kHz (or 48kHz) and describes each sample in 16-bit words. High-resolution audio leaves the studio as 96k or 192k/24-bit PCM – sampled at 96kHz or 192kHz, and each sam-ple described in a 24-bit word. In its raw state this needs very high

A roundup of the latest Everyday News from the world of

electronics

NEWS

MQA: high-resolution Internet-streamed audio – report by Barry Fox

First, what exactly is MQA? Well for starters, it’s not ‘Master

Quality Audio’, as the chair of a panel session recently organised at Metropolis Studios by Warner Music to mark the launch of some Debussy tracks in MQA thought, until publicly corrected by Bob Stuart, the brains behind the MQA system. It’s ‘Master Quality Authenticated’.

High-quality, low-bandwidth streamingThe main objective of MQA is to stream high-resolution audio over the Internet, from legitimate online sales sites, at a manageable and afford-able data rate of slightly over 1Mbps. Also, the MQA de-coder displays a blue light when it ‘authenticates’ the source as genuine Master Quality.

Bob Stuart de-scribes the way MQA works as ‘mu-sical origami’, be-cause the encoder folds some of the high-resolution de-tail into bit space that is otherwise largely unused. An MQA decoder then recovers the hidden data and uses it to rebuild the original high-resolution signal. The system is backwards compatible, in that an ‘ordinary’ non-MQA decoder can still deliver a CD-quality signal.

Data loss?There is hot debate over whether the MQA process is ‘lossless’, with the source input and decoded out-put mathematically identical – or whether it is ‘lossy’, with some data lost in the process. There is more debate over whether or not any ‘lossiness’ is or is not audible.

News (MP 1st & MK) – JUNE 2018.indd 8 17/04/2018 14:41

Everyday Practical Electronics, June 2018 9

MQA: high-resolution Internet-streamed audio – continued Cellular batteries

New PV cell technology

PicoLog 6 launched

Pico Technology designed and manufactured its first data

logger, the ADC‑10, in 1991 with a simple scope and logging software package for MS‑DOS, so that users could achieve the three fundamental purposes of logging software: set up the logger, view the graphed data and save the capture to disk. These packages later became known as the PicoScope and PicoLog software.

While not much has changed with the three fundamental logging soft‑ware functions in 27 years, computing and technology have moved on consider‑ably, allowing faster setup, more advanced ways to re‑view the capture and almost unlimited storage capability.

Designed from the ground up to be intuitive from the outset, the newly launched PicoLog 6, available for download on Windows, Linux and macOS, allows you to set up the logger and start recording with just a few clicks of the mouse, whatever your level of data logging experience. Fea‑tures include:n Real‑time data collection/

displayn Virtually unlimited log‑

ging capacity to PCn Robust database format

minimises data loss

Few toys have captured the public’s imagination quite like the Rubik’s

Cube. Competitions have been held to find who could solve the Rubik’s Cube the fastest by hand, then engineers started building robots to solve the cube at lightning speeds.

MIT students Ben Katz and Jared Di Carlo took up the challenge. ‘The gist is that there is a motor actuat‑ing each face of a Rubik’s Cube,’ ex‑plains Katz. Custom‑built electron‑ics are then used to control each of those motors. The robot also has a pair of webcams pointed at the cube. ‘When we tell the robot to solve the cube, we use those webcams to iden‑tify the different colors on the face of the cube,’ says Katz.

Di Carlo wrote software that iden‑tifies the colors of each individual part within the cube to determine the cube’s initial state. Then they use ex‑isting software to instruct the robot on how to move the cube’s faces.

The result? They set a new world re‑cord of 0.38 seconds. See the video at: https://youtu.be/OZu9gjQJUQs

switches on its blue light to signify that the stream is ‘authenticated’ and uses the bottom 8 LSBs to re‑build the original 96/24 high‑reso‑lution audio.

This begs several questions, apart from the basic issue of lossy or lossless. For instance, if people

Researchers from Imperial College London have fused living and

non‑living cells for the first time in a way that allows them to work together, paving the way for new applications.

The system encapsulates biologi‑cal cells within an artificial cell. Us‑ing this, researchers can harness the natural ability of biological cells to process chemicals while protecting them from the environment.

This system could lead to appli‑cations such as cellular ‘batteries’ powered by photosynthesis, synthe‑sis of drugs inside the body, and bio‑logical sensors that can withstand harsh conditions.

with limited data plans use MQA high‑resolution material for CD‑quality listening, they will be pay‑ing for around four times as much for data as they would if the source were 320kbps MP3 – will they hear the difference on their playback system?

n Simple and complex program‑mable alarms

n Up to four independent graph displays

n Channels and graphs can be scaled using lookup tables or equations

n Data can be exported as CSV, clip‑board image or PDF

n Supports multiple different Pico data loggers on same PC

PicoLog 6 software is designed for use with all current Pico Technol‑ogy data loggers, ranging in price from £95 to £459. Further informa‑tion available at: www.picotech.com

+ 44 1256 812812 • sales@hammondmfg.eu • www.hammondmfg.comDie-cast enclosuresfl anged & waterproofwww.hammondmfg.com/dwgfl .htmwww.hammondmfg.com/dwgw.htm

01256 812812sales@hammond-electronics.co.uk

News (MP 1st & MK) – JUNE 2018.indd 9 17/04/2018 14:42