Product category:
Stand-Alone Instruments
News Release from: TTi (Thurlby Thandar Instruments) | Subject: OPT-2711
Edited by the Electronicstalk Editorial
Team on 03 September 2004
Generator answers Dolby Digital test
demands
The OPT-2711 Dolby Digital generator has been added to the Audio Precision range of audio analysis systems, available exclusively in the UK from TTi (Thurlby Thandar Instruments).
The OPT-2711 Dolby Digital generator has been added to the Audio Precision range of audio analysis systems, available exclusively in the UK from TTi (Thurlby Thandar Instruments) The combination of an Audio Precision 2700 series audio analyser and Dolby Digital generator is the world's fastest, most accurate way to test to the Dolby Digital standard
This article was originally published on Electronicstalk on 12 May 2000 at 8.00am (UK)
Related stories
Compact bench power supply provides 175W
The EX355, new from TTi (Thurlby Thandar Instruments), is a single-output laboratory DC power supply providing an output from 0 to 35V at 0 to 5A.
Programmable power-supplies offer outputs to 1kW
The XHR range of programmable power supplies, offering output ratings up to 1 kW is power-factor corrected for low current draw and reduced generation of input current harmonics.
Now, with the new unit, manufacturing, R and D and verification engineers and technicians can test quickly and accurately to Dolby Digital standards.
Audio Precision's exclusive closed-loop system allows completely automated Dolby Digital testing and verification while avoiding the frustrations common to other solutions.
Until now, testing compressed audio decoders such as Dolby Digital has been time-consuming and inflexible.
Further reading
Low-pass filter meets digital testing requirements
The new Audio Precision S2-AES17LP filter, now available exclusively in the UK from TTi, meets the requirements for digital audio testing laid down by the Audio Engineering Society.
Programmable synthesised 1GHz RF generator
The TGR1040GP from TTi (Thurlby Thandar Instruments) is a programmable synthesised RF signal generator with a frequency range up to 1GHz.
Test engineers have to be able to ensure that all modes of the decoding process are working correctly, and that the digital/analogue conversion does not degrade the audio quality after decoding.
Problems created by this situation include lengthy test times, lack of control, and incomplete testing.
The Audio Precision OPT-2711 closed-loop solution solves these problems.
The OPT-2711 Dolby Digital generator can encode into Dolby Digital any of the wide range of digital stimulus signals available within a 2700 Series instrument, with both the stimulus generation and the Dolby Digital and IEC 61937 parameters under program control (using AP Basic), if desired.
The decoded multichannel outputs of the device under test can be routed through an audio switcher and into the 2700 Series analyser, once again under program control.
The stimulus signals and the integrated control of switching, sweeps, measurement and display can thoroughly and very quickly test units that incorporate Dolby Digital decoder functions.
The IEC61937 panel allows users to choose metadata and encoder processing options.
Metadata are decoder instructions embedded in the digital bit stream.
These are used to control decoding functions like dialogue normalisation level, dynamic range compression and down-mixing.
Since all the encoding parameters and metadata can be controlled via OLE instructions, scripts can be used to allow complete automation of decoder functional testing.
For example, the coding mode (3/2, 2/1 etc) can be stepped through all eight possibilities under program control.
Numeric parameters like dialogue normalisation level can be swept like any other 2700 Series setting.
This permits "closed loop" sweeps of the entire encoding/decoding process.
Some decoder features like dynamic range compression involve complex response curves.
With an exclusive Audio Precision feature, the compression value can be swept directly to expedite the testing and simplify analysis of the test results.
• TTi (Thurlby Thandar Instruments): contact details and other news
• Email this article to a colleague
• Register for the free Electronicstalk email newsletter
• Electronicstalk Home Page
Search the Pro-Talk network of sites
