The history of the ASR Emitter

Transcription

1 ASR Audio Systeme Friedrich Schaefer Hohe Straße 700 / 5A D Herborn Phone / Fax / asr@asraudio.com The history of the ASR Emitter In the beginning of the 80s the company Schäfer and Rompf presented the amplifier Emitter. The ASR Emitter - the musical amplifier - sender of the emotions - was born! A series of amplifier that are quite different from usual designs with a long term history of developments. The ASR Emitter obtained from the first unit ON an extraordinary but logic design, which was a result of practical considerations : a chassis made of acrylic with large heat sinks on both sides a simple, logical control with only three knobs Why a chassis made of acrylic- because it just sounds better! We found out that an amplifier with pure acrylic chassis sounds more musical than the same building in a metal casing. Acrylic has simply much weaker and less resonance compared to steel or aluminium, one reason why there are so many beautiful turntables and speakers are made of acrylic or similar materials. A knob is simply better in the hand is a push button-turn is more logical than buttons. The technology of the ASR Emitter has been unconventional from the beginning on : The purpose was from the very beginning, to combine the accuracy and power of efficient transistor amplifiers with the inner peace and balance to good tube amplifier. The Emitter was in complete departure from the usual design principles of pre- and main amplifiers. The Emitter is from his Principe a power amplifier with input selector switch and volume control. This shortens the signal path and there is not need for the usually needed pre-amplifier. The Emitter pursued so from the beginning the concept of the shortest possible signal path and was the pioneer for many other developments later presented a manufacturer of High-End integrated amplifiers. With the separate power supply the AC power network network disturbances and transformer vibrations are kept outside the sensitive amplifier circuits!

2 Of course electromagnetic and electrostatic influences can be suppress in separate casings But the negative impact of transformer vibrations to the flow of music could be kept away best with a separate case for the power supply parts The removal of the power supply parts was one large step of the development - to enter new paths to come more near to the original Live performance. Mos Fet transistors with their tubes similar transfer characteristic curve had been from begin on for the output stage. combine power and precision with homogenous sound. Mos Fet transistors had been the principal design characteristics of the ASR Emitters from the beginning until today- although the circuit design of the ASR Emitter inside has changed over the years. At the beginning, only a few Emitters had been manfactured for friends, but the news about the specific sound character of the ASR Emitter spread around music lover - up to the Audio press at the first review in Stereoplay in 1985, the Emitter I immediately had been classified in the absolute High End top class. Then the story had gone on - always more Emitter had been ordered and sold - the company ASR Audio grew from its small beginnings to the present size with large amounts in export to the whole world. The Emitter - the first generation - the base on which the future was built. The first Emitter were built in The first series of only 4 pieces had lying heat sinks on the side. The next has got a more conventional design with separate boards per channel, with a large 220 mm high heat sinks had been positioned on each side. The first models of the Emitter had the transformers built in the main case. From 1983 on the Emitter had only external power supplies. The first external power supply unit used a relatively small aluminium case (300 x 200 x 100 mm). In the case there had been two large torroidal transformers and a small standby transformer. Two high current relays had been used to switch ON the main transformers and to limit the switch on current. A strong multi wire cable with a large 20 pole connector has led the AC Voltages into the Main unit. The rectifiers had been positioned in the Main unit. Since 1985, a new construction with one large motherboard: From 1985 on the Emitter got one large main board for both channels. The buffer capacitors are mounted underneath to get short connections. This basic construction Principe is still in use. With this new construction the Emitter I could be to built lower, the height of the heat sinks had been reduced to 170 mm. From the year 1987 on, the rectifiers has been positioned into the power supply case, instead of in the main unit before. The much larger power supply case used a 19-inch chassis with 3 HE (430x 290x 125 mm) and even more capacitors could be built as a pre-buffer in the PSU casing. With this much more complex technology the Emitter sound got much more precision and stability.

3 In 1988, the commonly used torroidal core transformers had been replaced by the much more stable and better sounding PM ( Philbert Mantelschnitt ) transformers. In 1990, the Emitter two separate capacitor boards for the left and right channel, and an offset control has been added. From 1991 On, a completely new developed Emitter has been presented : Since 1991, the completely new developed Emitter plus version has been equipped with a double-sided Main board. Mos-Fet transistors had been used in all stages. At first a manual version with a rotary potentiometer as volume control has been released. At request this Emitter Version was available as option with a 24 position pole switch instead of the potentiometer for volume control. From 1992 on the Emitter was available a relay-step-switch with micro-controllers and remote control. This functions had been implemented before in the new board. From 1993 on the Emitter this functions became standard. From 1993 on the Emitter power supplies had been equipped with an energy-saving circuit. The additionally low-power mode can be used at low levels. In this mode a lower (25%) output power comes together with only 30% of energy consumption. The Emitter II plus was then equipped with two separate channel power supplies. From 1994 the Emitter got a new bright LED display with large 25 mm digits for the Volume control instead of the from 1992 on used double-line LCD display with 5 mm characters. For then on pure silver wiring has been used for the signal wirings, for example to the RCA Sockets. At the end of 1994, Mr. Rompf resigned from the company Schäfer and Rompf. He made his hobby - motorcycling to his career and opened a motorcycle shop. The company was renamed to the End of 1995 in ASR Audio Systems Friedrich Schäfer. In 1995 we presented the optional High-Definition Version of the Emitter. One major part of the HD Version was the use of ultrafast Schottky Rectifier normally used in Switch mode power supplies. In extensive listening sessions we evaluated the sound effect of various types of power cords.. Finally we decided to use a ferrite shielded power cable for the HD Versions there had been important changes: From 1997 on, the Emitter HD was delivered in a new version. We used very powerful especially designed for Audio new Output-transistor made from Toshiba. They allowed a better performance from the higher output capacity with a significantly higher greater impulse capacity. Additionally we used faster Capacitors and a complete new designed Superfast power supply with a total of 56 Schottky ultra-fast rectifier diodes. The power supply case was then manufactured using much thicker sheet metal what made it much more stable, what resulted in a more grounded sound. It was then painted with a nice structure laque.

4 The input stage has got a separate Supply direct from the power supply. Therefore a larger connecting cable and a new 30 pin connector (instead of only 20 pole previously) at the PSU had been necessary. For the standby transformer we used also a high-quality shielded PM transformer. The shielding lowers the interference between power network and the power supply in the amplifier. With all these improvements the Emitter have got a much more precise sound staging with greater dynamic combined with a large internal peace and stability of the reproduction. In 1999 the Emitter Plus versions had been equipped with parts of this new technology, like the fast diodes from the High Definition power supplies, and had been from then on a small HD-Version. Since summer 1997, a further option for the Emitter HD was available : An additional battery power supply for the input stages. In mid 1999,the battery power supply got a new developed board with modified arrangement of the components and a battery status display. Since year 2000 the Version Blue was available, which includes a blue display, blue LEDs on the main board and silver heatsink and silver knobs From 2002 on the Emitters got a much better equipment as standard : 1. New ASR design remote control milled from solid Corian with mechanical switches with perceptible click, knobs made from stainless steel and a flat lithium battery for long life. 2. The Emitter HD had been equipped with a balanced input as standard - no extra charge. 3. New board for the balanced input with specially designed ICs and Dip switches with adjustable input resistance. 4. New ASR power cord "ASR Magic Cord" with stronger wirings and has a double shielding for lower losses and a greater dynamic. The outside it transparent (thereby silver optics instead of previously black). The new "ASR Magic Cord" became also more flexible. 5. New, larger solid terminal with a larger knob for Emitter I just like the ones used at Emitter II 6. New encoders for the volume control that runs more smoothly. 7. New main board in the ASR-power supplies. The arrangement of the components has been optimized, two main transformers are switched separately with 6 relay from energy saving into the full power mode. All 8 voltages and the operational modes are shown directly with 12 LEDs. The Leds can be seen through a display window in the front panel of the power supply units On request the power supplies could be equipped with a built-in active filter. This came together with a large high-load fuse, what have a much lower resistance compared to the usual standard fuse.

5 New since September 2003 * new microcontroller with built in program memory result in more stable operation, and lower HF interferences. New since March 2004 * high frequency uncoupling of the heat sinks. This improves the dissolution of detail and the precision of the sound picture. New since October 2004 * modified filter in the battery power supply. Thus devices with Battery power units play clearly more dynamically and still with more punch in the low frequency region. * A new solid metal holder for the umbilicalcord from the main unit to the power supply. * New connection cable between the Emitter and power supply using low-loss insulation material. * In the Emitter power supplies is a standard low-loss high loading fuse and a larger 20-ampere power plug fitted. The lower net losses in connection sound Emitter dynamic, precise and the bass playing is tight. * The compensation of amplifiers in the Emitter can be increased with a switch on the motherboard. This increases the stability at difficult loads such as cables with high capacity or loudspeakers with critical impedances. The sound image becomes simultaneously something more round. In May 2005 ASR presented at the High End in Munich : The new Emitter Exclusive version 2005! The ASR Emitter Exclusive are equipped with complete new cases for the power supplies, a new very high-quality patch cord and transistor bars made out brass. The ASR Emitter II Exclusive has got new heat sinks. The new cases with the dimensions 460 x 320x 160 mm are a little bit larger than the ones before, have rounded edges and are manufactured out of stronger and thus more stable sheet metal. The side parts are manufactured together with the base plate from one piece. The entire structure consists of fewer but more stable parts. The Ventilation openings form a ASR Logo. Caused by larger available space the parts and pcb boards can be installed more separated from each other. Thus the transmission of fields and resonances are reduced. Also the Standby transformer is installed now lying instead of standing. The new ASR Emitter Exclusive power cases are about 3 kg more heavily than the predecessors, the entire structure are clearly more stable and have lower resonances. The new, clearly sturdier plugs originate from the industrial electronics and are supplied from the well known German manufacturer Harting.

6 The Battery Power Supply of the ASR Emitters Exclusive has got a complete new design : The Batteries are mounted now at the rear wall. The main pcb board is positioned in front behind the front plate. The charging transformer is installed central lying in the equipment. The control Leds can be seen from the front by the front plate window. The internal wiring has become shorter. The new housing has by the new, more stable structure has it smaller resonances, and sounds clearly better than the previous version. The amplifier part of the ASR Emitters Eclusive series has a solid transistor mounting bar made from massive brass. In the former models the bar ahs been made from black anodized aluminium. Brass is clearly heavier and has a substantially more harmonious resonance spectrum than aluminium. Brass is therefore also the material for many music instruments! The ASR Emitter II Exclusive are equipped with a new heat sinks with a changed, more rigid profile. By both changes the resonances in the structure of the ASR Emitter II Exclusive are lower. The new ASR Emitter Exclusive sounds still more dynamic and more precise than the former models.

7 The new Brass mounting bars : The new emitter Exclusive! New in January 2006 The Basis Exclusive power supply is now equipped with the solid new case and the professional Harting plugs that are used for the new Emitter Exclusive. By this the sound of the improved Basis Exclusive has become more sovereign and has got more details. The Emitter standard models have been improved with some advantages of the Exclusive models : The main units have the brass mounting bars, the new power cases and the Harting plugs of the Exclusive Version. The Emitters Exclusive are now equipped in series with the active system filter in the power supply unit. The Emitter II Exclusive is available with gold or chrome plated heat sinks on request. New in 2007 Improved Emitter Exclusive models : New : Gold plated pcb board with transparent solder mask New Option : Bypass Input and 2 balanced XLR Inputs Connection of 2 or more Emitter for Mono- and bridged operation The Picture shows an Emitter II Exclusive Battery with the optional WBT connectors

8 Since spring 2007 the pcb board of the ASR Emitters and the Capacitor Board are gold plated with transparent solder mask. The boards in the Trafo- and Battery PSU got a complete new design. The golden boards are the optimal combination with the teflon isolated massive silver wire we are using from for all signals from input to output. From the long time stable and durable surface with very low contact resistance the sound of the new version of the Emitter has got an even wider, more open soundstage, a smoother sound figure together with an improved precision and more impact in Bass. Through the transparent soldering mask the attractive nearly symmetrically designed board is clearly visible. Also the pcb boards in the power supplies had been improved and are now also gold plated. New Options : a second XLR input is available for EM II and a bypass input which bypasses the volume control- to use the Emitter together with a preamp as a main amplifier and for home cinema. The optional Digital control can be used to connect and control 2 or more Emitters. This can be used for several purpose: for home cinema with 2,3 or more Emitters, for using two stereo Emitters as mono amplifiers for each channel for Bi-Amping, for active operation by using one channel for high and one channel for low frequencies, as bridged mono amplifiers with about 4x Output capacity the Emitter II can deliver in this mode about 2000 Watts into 4 Ohms. In Thailand a customer is using 8 pieces Emitter II Exclusive Battery to drive a 4 way flat panel speaker from Wisdom Audio with 8 x 1000 Watt / 8 Ohm! The Basis Exclusive got the new power supply cases and Harting-connector.

9 Since nearly a third of a century, the ASR Emitter is now in production. He is a rocket solid stable player in the changing Audio market. The ASR Emitter, with its unique design and the many unusual detail solutions in combination with its round and balanced sound,, that invites for a long-term relaxed listening inviting is a special offer for the music connoisseurs. All Emitter models reproduce music very organic and fluid. The ASR Emitters are manufactured completely in Germany by experienced staff under pleasant working conditions in a quiet company located next to a forest, overlooking the green of a wood. Through constant optimization of production, the ASR Emitter for our customers has always been given the extraordinary effort to a high relative to the market offer quite favourable price. In its long production history the Emitter has always been improved in a sensitive way, the dynamics has grown significantly, the Emitter became more comfortable and efficient. But from the beginning of the ASR Emitter our customers are fascinated with its subtle, balanced and superficial effects during music playback, and offers our many thousands of customers relaxing music enjoyment since many years. By upgrading used Emitters with new parts the ASR Emitter is open for further developments within a model generation. For example, in many families the older Emitter goes to be a heirloom, often not sold, but passed in the family to your users. This is a sign of satisfaction of our customers. In the meantime the ASR Emitter had found followers worldwide. ASR has now a global distribution network in more than 40 countries.