Test and Measurement News

Prism Sound's dScope Brings Clarity and Versatility to Marshall Amps' R&D Lab

Cambridge, UK: When R&D engineers start fighting over a piece of test equipment it's fair to assume that the kit in question must be pretty special. Since its arrival earlier this year, Prism Sound's dScope Series III audio analyzer has been causing exactly this reaction at the Marshall Amps R&D facility in Milton Keynes.

Marshall amps and a dScope

"Everyone in the department loves it," says Marshall Amps Lab Technician Peter O'Neill. "It's so versatile and gives such clear results that it's become the one piece of equipment everyone wants. Thankfully it's very portable and easy to set up so we can move it from bench to bench quickly and easily. We haven't quite resorted to physical tugs of war over it yet, but it's been close!"

Prism Sound has been supplying successful high quality analogue and digital audio test solutions for over eighteen years. Prism Sound's solutions provide state of the art testing capabilities, backed up by consultancy and support services recognised as the best in the industry.

The company's dScope Series III is a comprehensive and powerful measurement system for analogue and digital audio generation and analysis, including digital audio carrier testing and testing of Windows sound devices. This industrial strength audio test and measurement system comprises a Windows PC (XP and Vista compatible) software application coupled with an external high-precision audio I/O processor for equipment-under-test (EUT) connections.

Marshall Amps chose the unit for its R&D department for its rich feature set and versatility. Peter O'Neill recommended it to the R&D department on the basis of previous good experiences with dScope Series III while working at Solid State Logic.

"The dScope is being used to test new developments across a variety of products, but in particular our flagship JVM410H amplifier," O'Neill explains.

The Marshall JVM410H is a 100 watt all-valve guitar amp head with 4 channels, each with 3 different modes, that provides almost limitless variation in tone at the touch of a button. Sounds can go from crystal clear to the heaviest distortion ever heard from any Marshall - and everything in between. The amp is supplied with a 6 button intelligent foot-switch allowing switching between channels, master volumes and effects loop.

"Our latest generation amplifiers are being built to much higher specifications in order to give artists greater versatility," O'Neill says. "With so much fine detail going into the design of the electronics and circuits, we needed a test system that was more critical and complex. We also needed a test unit that could cope with very fast calculations and present clear and detailed results that could easily be exported into other documents. dScope achieves all this - and more. It is very easy to set up and can be quickly configured for a variety of different applications."

The dScope Series III architecture makes the most of the processing and multi-tasking capabilities of the Windows XP or Vista platform to allow the system to measure many parameters simultaneously and quickly. The external I/O processor connects directly to the PC via a standard USB connection without any external adaptors, making it easy to use with a wide range of PCs, including laptops.

The external I/O processor includes precision analogue and digital outputs and inputs that are highly optimised for measurement applications. Precise and automatic gain ranging allows high resolution measurements over a phenomenal range from just over a micro-volt to 159 volts RMS, and from less than 1 Hz to over 90kHz. The dScope Series III I/O processor uses dedicated DSP to provide a wide range of real time measurements, as well as providing controlled degradation and analysis of AES3 and S/PDIF digital audio carriers. The dScope Series III software uses the host PC for almost unlimited number crunching and analysis options such as Fast Fourier Transform (FFT), power spectrum analysis, swept sine and multi-tone testing. The dScope Series III software also allows direct routing to and from installed Windows sound devices such as sound cards or bluetooth audio headsets as generator outputs or analyzer sources. Provision for electro-acoustic measurements, such as for loudspeakers or microphones, is also included in the new V1.21 software, subject to provision of a suitable external measurement microphone.

Marshall Amps are so delighted with the results they are achieving with dScope Series III that the company is considering introducing the unit to the production line.

"It's a great piece of kit and we all love it," O'Neill adds. "It has made a huge difference to our workflow and consistently provides us with the clear, accurate results we need to develop products within the lab."