Historical Radio Society of Australia
Our February meeting will welcome Ric Clarke and Tim Robbins who will demonstrate the Williamson amplifier. Ric and Tim are part of the Historical Radio Society of Australia's Hi- Fi and Audio Special Interest Group.
The Williamson is mono and pre-dates stereo by about a decade, and pre-dates speakers with cross-over networks similarly. We will also have a stereo version presented.
The mono amplifier to be demonstrated is an early Australian made version by Sydney based company Audio Engineers and using transformers made in Australia and has an accompanying original Williamson preamp (which is not common to find). Tim has other Williamson amps, in various stages of restoration, and some made in England, but he believes this example is best shown off for its local origin and its preamp.
The amp only puts out about 10-15W before being overdriven, so the meeting will not be ear piercing but will have adequate volume to listen to music. I will be bringing along my Technics SL-G700M2 streamer and Leak Sandwich speakers for both ends of the sound chain.
The Williamson amp design soon became plagiarised and modified, so many amps from the 1950's were referred to as Williamson but typically had significant differences.
I will be taking music requests for this meeting, so if you wish to have a track played please email me your selections. Two selections maximum and each track must be less than 5 minutes and if greater it will not be included. As we will be having a mono setup for part of the presentation preference will be given to those tracks that were recorded in mono. I will not be playing CDs on the night; all tracks will be streamed from Qobuz.
Dave Polanske
Programme Coordinator
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Steve Slyuter - SpectraFlora
Our first GM for the year with feature Steve Sluyter from SpectraFlora, presenting his 2- way Celata 88 Standmount Speakers. These are made in Winchelsea, 110 km south-west of Melbourne. The speakers are 4 ohm, ~86 dB/2.8 V, and are rated at 300W. I haven't yet heard a class D amp that sounded good through the waveguides.
When Steve was at the recent StereoNet HiFi show he had the speakers running with a laptop playing tracks connected by USB to an RME ADI-2 DAC, then through an Audio Research Ref 1 preamp into a Parasound A21 power amp. He will be bringing the same outfit to the presentation.
The following information has been lifted from the SpectraFlora website www.spectraflora.com and will give you an excellent insight into what to expect.
The Celata 88 by SpectraFlora is crafted in Australia using sustainably sourced Australian timber. The cabinets are made from hoop pine plywood, a native Australian species sustainably grown in Queensland plantations.
The horns are available in either hoop pine plywood or solid timber, which is either plantation-grown or salvaged. For instance, we offer horns made from plantation-grown Northern Silky Oak, Southern Silky Oak salvaged from Melbourne's eastern suburbs, and red ironbark salvaged from a former RAAF base in Dubbo.
The sound quality is exceptional, thanks to its innovative technology-intimate and engaging. We refer to the waveguide as a Dynamic Waveguide because its horizontal geometry is a waveguide, providing an open and transparent sound with constant directivity. It is a hybrid design because, in the vertical dimension, it features a traditional horn profile, which acoustically loads the compression driver to deliver a dynamic and captivating sound. In short, it combines the best of both worlds: the powerful dynamics of a horn and the transparent, even horizontal dispersion of a waveguide.
Our crossover design is the result of 11 months of measurements, modeling, and listening tests to optimise transparency, vocal clarity, dynamics, and instrument timbre. As the brains of the Celata 88, it delivers stunning sound across the Dynamic Waveguide, magnesium mid-bass, and Celata subwoofers. DC-biased by two 9V batteries, it features custom copper and aluminium foil capacitors and thick film resistors chosen for gorgeous, emotionally gripping sound.
The Celata 88 base model speakers retail at $35,000.
Dave Polanske
Programme Coordinator