Savour the sound

Hi-fi systems are becoming increasingly complex. Highly sensitive components provide a broad sound spectrum and, depending on the price range, can provide a good or even extraordinary music experience. However, this rising complexity also has a downside, namely that the perception of sound can be tarnished by undesired interference in all relevant audio frequency ranges. This can be caused by any additionally connected AV equipment, computers or digital devices. Even network cables or NF connections can generate many of types of interference. Connoisseurs therefore ensure that components are of higher quality and avoid these undesirable side effects.

Perfect production, technologically state-of-the-art, combined with timeless, clear design may be how music aficionados describe the products of AVM, the company founded as Audio Video Manufaktur in 1986 in the Baden-Wuerttemberg town of Malsch by Günther Mania. The goal of the manufacturer is to enable the customer to enjoy every piece of equipment using several senses — sight, touch and in listening to the music. The company's own research and development department has received awards and titles around the world for its achievements.

Udo Besser, Managing Director and owner of AVM, commented: “In order to make this kind of quality possible, with high output and a perfect sound, we require suitable, high-quality components. And we get these from Rutronik – together with consulting and design-in support wherever expertise on products, technology and the market come together.”

An award-winning amplifier

This was the case with the modular preamplifier, the Ovation PA8. This device, which has received awards from specialist music magazines around the world, has been designed as a control unit for high-quality music playback and is therefore fitted with gold-plated conductors and connectors, among other things. It is supplied in a solid aluminium housing with a blue illuminated, dimmable visual display and extensive menu functions. The numerous expansion opportunities enable the user to continually expand the preamplifier and adapt it to their specific needs. With eight connectors for input modules and three slots for output modules, the device is future-proof, very easy to customise and can grow to meet requirements in the longer term. With the PA8, AVM had set out from the start to develop a modular high-end preamplifier that would complete the Ovation line of products, which represented the highest quality segment.

“We have extensively revised and consistently refined the technology in our products to provide more power, the perfect sound and reduce energy consumption. We include new technology that enhances music and the emotional experience. And only this technology,” comments Günther Mania, Head of Development at AVM.

Preamplifiers pass the signals from source equipment, such as tuners, CD players and record players, to the end device. Characteristics that quantify the quality of this type of device are voltage gain, linearity, insensitivity to foreign signals and an extremely broad usable frequency range. They also include low noise and a broad overload margin, in other words the ratio between the nominal and maximum input voltage, and these are keys during optimisation. Preamplifiers generally have control elements that can change the output voltage or volume. In analogue terms, these control elements are potentiometers or variable resistors. In digital technology multipliers are used, for example.

If you want to offer the music aficionado the best possible quality, you need to install the highest quality components. But the mass of components on the market with shorter and shorter lifecycles is making it increasingly difficult to keep track. As a specialist for electronic components with close relationships to the manufacturers, Rutronik can help our clients to select the appropriate parts from this mass.

Quality takes precedence

The engineers at AVM selected a high-quality component that exhibited superb audio quality specifically for the volume control of the Ovation PA8. Cutting costs in the quality of the audio and volume control ICs can cause the control voltage for the audio and volume inputs to drop and cause power surges, overheating or circuit faults. Moreover, discharges, voltage gains or cable reflection can also cause significant discharges within an amplifier. All of this can in turn considerably impair the quality of the sound and thus the perception of a music aficionado. This shows how the volume control is more than just something to reduce the signal and how it therefore had to meet AVM's high requirements.

Rutronik's expertise in the technical support and development of innovative products has served the Baden-Wurttemberg company well. The component distributor found what it was looking for with the Japanese specialist New Japan Radio (NJRC). After acquiring samples and serial parts and presenting the products in question at AVM, it quickly became apparent which part would be integrated into the Ovation PA8 preamplifier. The Muses 72320 volume control IC was selected. Of critical importance to AVM was that the components should operate more dynamically with lower sound levels than other modules, but also handle surges of up to 18V. Then came the 'lead frame'. This lead frame is a measure of quality in the high-end sector and consists of oxygen-free and highly pure copper. This provides an extremely low level of crosstalk between the left and right channels, which influences the sound quality greatly. The MUSES module continued to impress us with its broad volume range and low level of distortion and noise. With a dynamic range of up to 111.5dB, there is no noise to be heard here. Of the components that came into question, it was believed to have the best possible range of properties and is thus consistent with the state-of-the-art technology expected at AVM. This makes listening to music a truly emotional experience for music aficionados with the highest expectations.

Precision affects audio properties

The MUSES 72320 chip controls the volume electronically via two channels. A resistor, low distortion and an optimum signal/noise ratio for a low error rate during digital transmissions are responsible for the very good performance. All functions are controlled using a triple-channel serial bus. The operating voltage is between 8.5 and 18V.

In order to further influence the sound properties of the Ovation PA8, AVM required a number of other peripheral parts for the MUSES-IC. These too had to be carefully selected and tested for their suitability in terms of audio quality. After all, alongside the precision of a component, the sound is also of critical importance in AVM products.

Günther Mania adds: “Here we benefited from the broad range of products that Rutronik has to offer. This not only enabled the specialists at Rutronik to help us with the selection, but also allowed us to be sure that the components worked ideally in combination with each other, because this is the only way that we can create the end product that we expect.”

In addition to the MUSES-IC from NJRC, other components were used in AVM's preamplifiers, including microcontrollers from Microchip and high-quality capacitors and resistors from Vishay.

To achieve high-quality music playback via the PA8, AVM developed extremely complex circuit designs. To exploit the full audio potential of these designs, only the very best components were recommended, which were subjected to an additional selection process because they entered production at AVM's manufacturing facility.

The result shows that the searching and fiddling was worth the effort; the product has been positioned in the high-end market for some months now with great success, and has been received very well by customers across the globe, while being deemed to be the working reference by specialist magazines. The audio performance of the Ovation PA8 has impressed AVM so much that future products from the audio specialist will also be fitted with the MUSES-IC. All this with the single goal of making listening to music a truly emotional experience for music aficionados with somewhat higher expectations.