RCM has produced high fidelity equipment for many years. The work is inspired by a profound passion for music and its accurate recreation. Our work is fueled by this passion. We understand that accurate sound reproduction is a result of the combined quality of each element in a system. We have designed the Bonasus with many factors in mind in order to create synergy within any system.
Integrated Design – Integrated amplification is the optimal design for home use. It is compact, lessening the amount of space necessary for the system. It also makes the additional cables that are indispensable for separate amplification unnecessary.
Dual Mono Construction – Although the Bonasus is constructed within a single chassis, the housing conceals two independent power supply circuits for the pre-amp and power amp stage. In addition, the two channels are connected only through a ground loop. This design offers many advantages. The integration of all circuits within the unit minimizes electrical interference, especially from the power supply, while electrical separation of channels increases signal resolution.
Output Power – Less experienced users consider an amplifier’s output power a shorthand for quality (greater power = better equipment). However, we have found that most home hi-fi systems use between 0.1 and 6 watts to run their equipment. This revelation has convinced us that many audiophiles suffer from “11th Hour Syndrome” in their home systems: when the volume is turned too loud, the system stops playing music and starts playing noise. We eliminate this problem by supplying “only” 16 watts of power.
Vacuum Tube – The Bonasus is a tube machine because only tube construction enables full-range listening at lower volumes. This also allows us to construct an ultralinear Class A/B push-pull output stage. Output stages work best at certain conditions, so while this configuration is capable of delivering 30 watts or more of power, we have spent many hours testing and listening to determine the optimal level. The low output provides the best sound quality across the audio spectrum.
Circuit Configuration – Semiconductor constructions have many imperfections, which tend to interfere with circuits in low-power amplifiers. Proper circuit configuration in our amplifier ensures linearity across the entire power range. This means that smoothness across the frequency spectrum is not dependent on the volume.
No Feedback Loop – Feedback loops are a repair for imperfect circuits in high-power amplifiers. This is not necessary in our amplifier. Feedback loops decrease amplification levels, forcing the engineers to increase power output to provide “empty watts”. These designs have a negative influence on the sound. By eliminating the feedback loop, we have removed the need to complicate the design of the Bonasus unnecessarily, which creates better sound.
Power Supply – The Bonasus uses a traditional circuit with a tube rectifier. It also makes use of filtering capacitors and chokes. The first stage capacitor is a polypropylene part, followed by the chokes and electrolytic capacitors, bringing the total capacity to 1,680 μF per channel. The choke filtering is divided into two circuits, one each to the input and output stage. In the input stage there are additional polypropylene capacitors which decouple distortion. All other circuits within the amplifier are powered by a separate transformer.
Tube Checks – We equip our amplifier with a “Soft Start” function. This provides proper warm-up of tubes before switching to anode plate voltage. This increases the lifetime of the tubes.The Bonasus also has a circuit to test the condition of the power tubes, which allows the user to see when it is necessary to change them.
Chassis – The chassis has a great influence on the quality of sound, and we take the construction of our amplifiers very seriously. We use a very rigid steel chassis. It has great mass itself, which helps dissipate vibration from the inner parts. All transformers and chokes are shielded and held in place using a semi-elastic vibration-damping adhesive. The combination of the rigid chassis and vibration-damped parts allows the Bonasus to eliminate vibrations as soon as they occur, guaranteeing that they will never affect your sound.
Parts – The key to an amplifier’s sound is the parts used to construct it. We use parts from Kiwame, Riken, Bourns, Mills, Audyn, and Solen chosen after many tests and experiments to create the best sound. In addition, the parts in the signal section are mounted without a PC board; we use point-to-point soldering. This same level of research has gone into our tube selections
Innovative Design – The design concept behind the Bonasus amplifier is rather imaginative. The sound of the amplifier is primarily shaped through the DC coupling of the input stage and the AC heating of the tube filament. This can only be successfully achieved by providing a main transformer of the absolute highest quality and through very judicious routing of the amplifier wiring.
The RCM Bonasus amplifier uses traditional, trusted and verified technical solutions while providing the highest quality of sound that modern technology is capable of delivering. The result is an amplifier which is the perfect choice for true music lovers