nanophon was an engineering company that specialised in digital audio. As well as developing a range of custom and niche products, nanophon also provided design consultancy services for other manufacturers.
Contact details
Client list
Engineering experience
Standards development

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Hardware Analogue, digital and mixed-signal design 
A-D and D-A conversion 
Phase locked loop and clock systems 
Microprocessor control 
Design for manufacture and test 
Verilog design
ASIC prototyping using FPGA
Digital Signal Processing Filter design 
Noise shaping 
Unobtrusive processing and control 
Time or frequency domain block processing 
Signal processing algorithm development 
DSP programming 
Testing and analysis Performance measurement 
Mathematical modelling 
Interfacing standards compliance 
Electromagnetic compatibility

Contacting nanophon
Julian Dunn, Director 
Nanophon Limited 
209 Mill Road 
Cambridge CB1 3AN 
Telephone: +44 (0)1223 507741
Facsimile: +44 (0)1223 560188

Clients (1998-2001)

Some clients have asked not to publicise the fact that they are nanophon clients. The following companies are happy to be listed here.

Audio Precision Beaverton, Oregon, USA. 
Cedar Audio Cambridge, England
Prism Sound Cambridge, England
TC Electronic Risskov, Denmark
Yamaha Corporation Hamamatsu, Japan


Experience (1985-2001)

We have undertaken the following projects either at nanophon or previously.


Analogue brick-wall filters for A-D and D-A conversion (1985).

Small digital mixers for live broadcast applications.

Digital broadcast variable emphasis limiter for BBC Radio Three (1987).

Simple mixer/format converter for CD mastering applications.

Sub-sample variable delay unit for audio-video synchronisation.

Dynamic range controllers for broadcast.

Prototype loudspeaker distortion correction system.

Jitter tolerance/sensitivity test tool.

High performance (120 dB) A-D converter with noise-shaper.

Higher performance (130 dB) A-D converter module (with 32 bit output).

High performance multi-format precision D-A converter.

High performance 96 kHz D-A converter with custom filtering.

Jitter attenuation for IEEE1394 sample clock transmission.

Research Use of AES3 over legacy cabling systems.

Interconnectivity problems with early AES3 implementations.

Testing the reliability of coaxial MADI.

Disc-related playback differences in CD players.

Jitter sensitivity of high-end consumer D-A converters.

Subtle digital ‘brick-wall’ filter artefacts.

IEEE1394 isochronous channel jitter.

Standards development

Nanophon took an active interest in the development of digital audio standards and supported that development through contributions in the relevant AES and IEC TC100 standards working groups. This included contributing towards the following new standards and specifications.

Interface standards and specifications

AES3 ‘Serial transmission format for two-channel linearly represented digital audio data’

AES5 ‘Preferred sampling frequencies’

AES11 ‘Synchronization of digital audio equipment in studio operations’

Draft AES42 ‘Digital interface for microphones’

IEC60958-1 ‘Digital audio interface—Part 1: General’

IEC60958-3 ‘Digital audio interface—Part 3: Consumer applications’

IEC60958-4 ‘Digital audio interface—Part 4: Professional applications’

IEC61883-1 ‘Consumer audio/video equipment—Digital interface—Part 1: General’

IEC61883-6 ‘Consumer audio/video equipment—Digital interface—Part 6: Audio and music data transmission protocol’

IEC61937 ‘Interface for non-linear PCM encoded audio bitstreams applying IEC 60958’

1394 Trade Association ‘Enhancement to Audio and Music Data Transmission Protocol’

Measurement standards AES17—‘Measurement of digital audio equipment’

IEC61606—‘Audio and audiovisual equipment—Digital audio parts—Basic methods of measurement of audio characteristic’

nanophon principal, Julian Dunn, was the co-ordinator of the AES task groups that formulated the amendments to AES3 for jitter specifications and for 96 kHz support in AES3 and AES5. He was the chair of the AES standards working group SC-02-02 on digital input/output interfacing.