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PRODUCT SHOWCASE Elan RMA-02 Challenger studio monitor amplifier Elan Audio is one of Australia’s leading producers of professional audio equipment, widely used in recording studios and broadcast stations. Their RMA-02 stereo power amplifier, rated at 200W per channel is compact but does not have fan cooling, to ensure quiet running at all times. The RMA-02 Challenger is the result of an interesting approach to producing a high power stereo amplifier for studio monitoring use. It is housed in a two-unit rack case and is fitted with 3-pin XLR connectors for its balanced inputs. Its speaker outputs are unbalanced and uses large binding post terminals. For lightness and corrosion resistance it uses an aluminium chassis and it weighs just 6kg all up. Separate volume controls are used for each channel, although we anticipate that in most applications (driven by a mixer) these would be set to maximum level. The only other control on the front panel is the on/off switch. So while many studio monitor amplifiers tend to be big and bulky, the RMA-02 is quite compact. This has come about partly because the designer, Poul Kirk, has opted for a relatively modest power supply using a compact toroidal power transformer producing unregulated ±70V supply rails. This arrangement gives good headroom (ie, more music power on typical program). As such, it is intended for studio monitoring and high quality domestic installation. According to the designer, it is definitely not intended for disco, stage or sound reinforcement work. The power amplifiers themselves use a fully symmetrical circuit, with complementary differential input 74  Silicon Chip stages, each with their own current sources. The output stage employs rugged 40MHz complementary bipolar transistors, considered by Elan Audio (and us!) to produce better quality sound than power Mosfets. Possibly the most interesting aspect of the design is the use of a split feedback network with separate paths for high frequencies and low frequencies. There is heavy negative feedback at low frequencies, giving low distortion and high damping factor, as required for good low frequency loudspeaker performance. At the high frequencies, feedback is more moderate and this claimed to make the amplifier more tolerant of unpredictable loading effects of loudspeakers, crossover networks and speaker cables. As a result of the above design philosophy, the power ratings are quoted as short term only, not continuous. Power outputs are listed as 200W RMS into 8Ω loads, 300W RMS into 4Ω loads and 400W RMS into 2Ω loads, although testing at this latter load impedance will blow the fuses. Harmonic distortion is listed at .015% or less at 1kHz at up to 100W and less than 0.5% at 10kHz. Signal-to-noise ratio is -102dB unweighted (20Hz to 20kHz) with respect to 100W into 8Ω.Frequency response is very flat; 0dB at 20Hz, -0.1dB at 20kHz and -1dB at 40kHz. We ran through the gamut of tests on the RMA-02 and confirmed every figure in the specs – that is a little unusual in itself. Even more satisfying were the protracted listening tests. Using a wide range of CDs, the RMA-02 always gives a good account of itself, with plenty of power, very low background noise and very clean sound at all times. It would make an ideal studio monitoring amplifier (as intended), especially as it has no cooling fan. Contact: Elan Audio 2 Steel Court, South Guildford WA 6055 Tel: (08) 9277 3500 Website: elan.com.au www.siliconchip.com.au BitScope USB digital ’scope, logic analyser & waveform generator The BitScope BS300 is a high performance USB based dual channel DSO and Logic Analyser for use with Windows and Linux PCs. It has an input bandwidth of 100MHz and supports simultaneous analog and digital data capture at rates as high as 40MS/s. An integrated 10MS/s arbitrary waveform generator option is also available. Standard accessories include 100MHz oscilloscope and high speed logic analyzer probes, USB interface, cables and power supply. The BS300 software integrates five powerful test intruments in one easy to use package: a DSO, Logic Analyser, Dual Channel Oscilloscope, Spectrum Analyser and XY Phase Analyser. The range of options available include the built-in 10MS/s arbitrary waveform generator, an ethernet interface with full Internet connectivity, and expansion PODs. Additional software packages are also available. If you have specialized test or data acquisition requirements, the full BS300 programming API is published allowing customized “virtual instrument” applications to be developed, and the BS300 POD interface provides full access to the analog and logic capture signals as well as data, control and Contact: power lines making the de- BitScope Designs velopment of new BitScope Tel: (02) 9436 2955 powered POD devices easy. Website: www.bitscope.com Bluetooth Kits for Emona Emona Instruments has been appointed the Australian distributor of the Teleca range of Bluetooth application development and training kits. Teleca is a Swedish based specialist Bluetooth R & D consultancy. Teleca’s Bluetooth modules and Host Stack Software were developed by Ericsson, the owner of the Bluetooth trademark. Teleca’s range of Bluetooth kits are ideal for companies looking to build and test their own Bluetooth applications and products, as well as universities and colleges wanting to provide students with hands-on training in the theory and applications of Bluetooth short-range wireless communication. Teleca’s full-featured Development Kit is approved as a Blue Unit by the Bluetooth SIG, Contact: making it suitable Emona Instruments Pty Ltd in qualification and 86 Parramatta Rd, Camperdown NSW 2050 pre-qualification Tel: (02) 9519 3933 Fax: (02) 9550 1378 Website: www.emona.com.au testing. www.siliconchip.com.au August 2003  75 AEMS acquires T&M equipment brokerage. Australian Electronic Manufacturing Services (AEMS) have recently acquired the test and measurement brokerage (re-sale) business assets from Megatron. AEMS is a Contract Electronics Manufacturer and Service Provider with over 550 staff located in 4 sites throughout Australia and New Zealand. (www.aems.net.au) This acquisition provides AEMS with the Intellectual Property of the much-acclaimed equipment brokerage web-site developed by Megatron (now http://broker.aems.com). AEMS will continue to sell a vast range of used test and measurement and telecommunications equipment suitable for everybody from contractors and hobbyists to the professional technician. AEMS have established an extensive display facility, which provides the capability for viewing equipment and performing on-site, basic functional testing of the units. For items found to be faulty, AEMS will offer a repair service to ensure that items sold are fully functional. AEMS Brokerage currently provides equipment disposal services for a number of Australian organisations. In addition, AEMS is in the process of expanding this portfolio of sources of used equipment and is currently offering its services to any company faced with the disposal of surplus test and measurement equipment. AEMS expects that any vendor utilising this service will achieve a far better return than the traditional method of disposal via auction. AEMS has established an extensive database of overseas dealers and will continue to promote product to these whilst increasing exposure to Australian end-users. Enquiries can be made to Alan Robinson (arobinson<at>aems.net.au). Contact: AEMS Pty Ltd 8-10 Kitchen Rd, Dandenong Vic 3175 Tel: (03) 9212 4222 Fax: (03) 9212 4020 Brokerage website: broker.aems.net.au USB-baseddata acquistion module Logitech’s new USB PC headsets The USB-based Labjack U12 data acquisition and control unit is an easy-touse plug-and-play USB device which operates completely under software control (no jumpers or switches to set) and no power supply is required. Up to 80 of the 100 x 150 x 25mm LabJacks can be connected to one USB port It features eight single-ended, four differential 12-bit analog inputs with a ±10V range. With up to 8 kilosamples/sec (burst) or 1.2 kilosamples/second (stream), it supports software or hardware timed acquisition and triggered acquisition. It also features PGA with gains of 1, 2, 4, 5, 8, 10, 16, or 20V/V and has two 0-5V analog outputs, has 20 digital I/O (up to 50Hz per I/O) and a 32-bit counter. The software packaged with the Labjack runs on Windows 98SE/ME/2000 and XP. It includes JLogger, a datalogging program; JScope, a virtual oscilloscope program; an ActiveX driver so you can write your own VB, Delphi and VB programs; sample VB and Delphi programs and Labview VIs. Labjack U12’s are being used for research, monitoring and control purposes in private Contact: companies and Ocean Controls public organisa- 4 Ferguson Drive, Balnarring Vic 3926 tions, universities Tel: (03) 5983 1163 Website: www.oceancontrols.com.au and colleges. Logitech has released a new range of headsets that bring superior audio quality to people who want the best for voice chat, online gaming, music listening and speech recognition. Included in the range is a USB model as well as two conventional systems. With an expected retail price of $89, the Stereo USB Headset offers advanced digital USB technology for superior audio clarity and the simbroadcast quality plicity of a single USB plug-and-play connection. It has a noise-cancelling microphone and an adjustable headband engineered for a comfortable fit. The design allows microphone placement on either side of the head. Manufactured in Australia They are available from most Harbuch Electronics Pty Ltd 9/40 Leighton Pl. HORNSBY 2077 computer products Ph (02) 9476-5854 Fx (02) 9476-3231 retailers. 76  Silicon Chip AUDIO MODULES www.siliconchip.com.au