Preamplificador de Referencia B-275: ¡preamplificador de línea de Referencia Absoluta!
Densen now introduces the new top of the line preamplifier; the B-275. The B-275 may mark a landmark leap for Densen, but actually is a well proven design, having being used internally at Densen
as reference for several years. Now when it has become commercially
available, it has been refined to meet the needs of discerning
audiophiles around the world.
Densen has always had a strong attention to the powersupplies of their products. Over the years this has resulted in Densen using exclusively their own powersupply capacitors which are designed specifically for the circuits they are being used in, instead of relying on standard capacitors. The Densen powersupplies has always contained several separate supplies, focusing on clean power to all stages of the products, and the transformers have always been custommade and most of them encapsulated in epoxy to minimise vibrations influence on the delicate audio signals on the PCB board. Now Densen takes these attentions to details to another level, with the introduction of the Densen B-275.
The Densen B-275 is the first Superleggera product from Densen. The term superleggera will not be unfamiliar to conneceurs of advanced sportscars, as this Italian term, meaning super light weight, has been used to describe the chassis of some of the best and most famous sportscars ever made.
The industry standard has been to build bigger and bigger products, with larger and larger circuits and powersupplies, resulting in cabinets both holding delicate audioelectronic and massive powersupplies. Densen has with the Superleggera products divided these into 2, allowing the audiocircuit to be totally separated from the powersupplies mechanically, resulting in a dramatic removal of the powersupply vibrations which will smear the signals of a normal amplifier. In the B-275 the huge powersupply has its own cabinet, while the delicate audiocircuit is in the Superleggera cabinet, where everything possible has been done to reduce the weight and remove vibrations. This has made a dramatic improvement of the sound, and where huge high end products normally is associated with dark and slow presentation of music, the words that springs to mind when describing the B-275 Superleggera is words like agile, precise, fast, dynamic and natural.
The B-275 simply let the music breath more freely, due to the removal of unnessesary weight. This is in line with Densens effort in previous models, where the attention has always been to make a light cabinet, but here it is obviously taken to extremes with the 2 cabinet solution.
The powersupply of the B-275 is placed in a cabinet named 2NRG. The 2NRG contains no less than 3 custommade transformers, each with 2 separate windings. Each audiochannel of the B-275 Superleggera has its own transformer and no less than 200.000uF and rectifying by the use of ultrafast and precise diodes. The third transformer supplies the microprocessor, display, input selectors and the advance relay driven volume attenuator. All in all the 2NRG has no less than 510.000uF in the form of 51 custommade capacitors.
The B-275 Superleggera itself contains further voltage regulation,
allowing a complete removal of interference between each part of the
amplifier. Therefore the B-275 itself contains a further 120.000uF of
powersupply capacitors, and several individual regulations.
The result of all this care to the heart of the B-275; the powersupply, means the B-275 can breathe freely.
An equally great dedication has been put on the audiocircuits. The B-275 Superleggera uses Densens unique non feedback single ended Class A topology, for a transparent, dynamic, refined and musically sound. Extreme care has been taken to avoid compromises. As such the B-275 features Densens advanced microprocessor controlled attenuator. In these times, digital volume controls are often used in even high end amps. However digital volume controls, typically contains over 500 components in a compact microchip, with all the complications this means to the tiny vulnerable audiosignals. On top of that, digital volumecontrols typically has poor performance at low signal levels, where they will have high distortion and time related distortions, resulting in listening fatigue and lack of transparency and details. And since normal listening is done at reduced signal levels, and not maximum output, this actually worsens the negative impact on the sound when using digital volumecontrols. Densen has therefore never used digital volumecontrols on all their products, opting instead for an advanced ultraprecise attenuator. This attenuator is implemented with the use of Vishay 0,1% lasertrimmed metal film resistors, giving a transparency and accuracy that is outstanding. Further the attenuator is calibrated by the user, by an interface with the amplifiers microprocessor. This means that the microprocessor that also takes care of the B-275s display, remote, inputselector and DenLink multiroom system, also takes care of the calibration of the attenuator to the listening level desired by the listener. The calibration is done in ½ db steps, allowing a high resolution, securing that the listener can always hit the precise listening level he desire.
The qualities of this attenuator should not be downsided, as this is perhaps the most advanced and precise volumecontrol currently used in the audio industri no matter price.
Further the microprosessor controls the B-275s option of installing a analogue surroundboard, which is a board that expands the B-275 to a true 7+1 analogue preamp, securing a precise and straight signal path for users who wants to upgrade the B-275 with a DVD or BluRay with either 5+1 or 7+1 analogue output, and with further poweramplifiers to control all speakers in such a system.
Audiophiles wanting to use the B-275 with a gramophone, can convert on of the B-275s line inputs to either a MM or MC RIAA input by the purchase of a dedicated phonostage to insert in the B-275.
The circuit itself is implemented using SMD technology, with the
components being mounted with a precision of 0,02mm and soldered in an
artificial atmosphere using nitrogen, to avoid oxidation of the
soldering over time.
The parts are the best possible, resistors being Vishay metalfilm, the transistors being ultrafast and precise types, while the capacitors are conventional leaded capacitors but are Densen custommade film capacitors for the critical parts of the circuit. All critical parts of the B-275 is encapsulated in metal boxes, to minimize interference.
The B-275 sets new standards for preamplifiers, and as Densens head honcho Thomas Sillesen states "for many years making superb preamps has always been a difficult task for the worlds high end manufacturers, therefore I am very proud we have been capable of providing discerning audiophiles and musiclovers with such an outstanding performer. I know such a bold statement, will result in the scrutiny of the industry, but we are prepared for that, feeling we have truly made a preamp that can be cherished for many years to come”