A hybrid passive attenuator for a balanced input/output of an innovated volume control mechanism that is improved even more draws out the music’s reality and the artist’s passion
Last year we released the highest grade hybrid passive attenuator [control meister CM-1000] that does not contain an active circuit and is distinct from the previous preamplifiers.
We adopted an ideal volume adjustment circuit that acquired a patent based on a new idea in the volume adjustment mechanism which can be said to be the key to an audio playback.
This time we reviewed the volume adjustment circuits and parts that were used for the CM-1000 and by changing its core size, material of the laminated core, thickness, and other winding materials, it became more fresh and dense and achieves a vast sound environment.
In addition, the passive attenuator [control meister CM-2000] which flexibly supports the balance input/output now vital to modern control equipment is released.
Adoption of newly developed high-performance core materials and winding materials
We reviewed the 0.2 mm thick permalloy material that was used previously and newly developed an "extremely thin super alloy material."
In addition, for the winding material, rather than the high pure copper wires that were used previously, we specially ordered PC triple C polyurethane wires which are optimal wires for audios. In combination with a large core shape, we reached an excellent characteristic of a high low–pass linearity and a delicate and calm high frequency and achieved an expression of a vast space.
Development of optimum winding specified for balance
We reviewed the attenuator transformer winding specifications from the beginning and developed an ATT transformer for balancing in which two ATT windings of the hot and cold sides of the balance connection are wound in one transformer. By utilizing the fact that there are two more ATT windings, it is also possible to create a signal (at the cold side) inside the transformer for the unbalanced input and to support a complete balanced output. Also, a high common mode rejection ratio (CMRR) was also obtained with the two windings that support the balance.
Since the transformer for a balanced sound volume adjustment circuit was composed with one CH1, excellent frequency characteristics and phase characteristics were actualized in a wide band, the phase distortion in the audible band was reduced and most important was that the freshness was high and a clear constant sound image is brought into effect.
Eliminate external induction hums and unnecessary vibrations
For external induction hums, a chassis base with copper plating on a solid 2 mm thick steel plate and a case cover with an induction hum shield is arranged. In addition, the magnetic shield material located near the transformer has a double structure.
The ATT transformer is floated from the main unit with a high damping rubber material and it prevents external vibrations from propagating. The front panel adopts a 20 mm thick slanted aluminum panel that is equivalent to the control amplifier CA-1000. By adding a walnut material base under the exterior case, unnecessary vibration is effectively eliminated by combining different kinds of materials and brings about playback sounds with a good S/N ratio.
Use of high quality parts
We adopted rhodium plated terminals made by Furutech which are reputed for having high-quality and high sound quality on the input and output terminals.
In addition, the foot adopts TAOC’s high carbon cast iron insulators which contribute to increasing the resolution of the sounds.