The volume control function called L type which changes the resistor of 28 points with a switch is adopted as the attenuator portions of AT-03-1A and AT-03-3A. Usually, many L types of a continuation variable type and much L pad type which passes only two resistors are used for the attenuator for audios. As for L pad type, the sound quality retail price according [ the resistor included in the source of a signal ] to a resistor only in two is held down to the minimum. However, since the number of the switches to pass compares with L type and two pieces' increases, it is disadvantageous at this point. Moreover, since impedance change becomes large at the time of the change of a switch, it becomes easy to generate a change noise. Although the system adopted as this machine is L type, the loss by the resistor to pass is suppressed to the minimum by adoption of a surface mount type resistor, and hardly generates the noise at the time of a contact change by it, either. The step interval of each switch point can adjust -38dB at a 2dB step from 0dB, and fine adjustment is possible for it. Moreover, the minimum volume can be extracted to -65dB and can respond to any level adjustments. It has succeeded in stopping so small that it having fitted in substance of less than 0.2dB and the difference of the right-and-left level which is a weak point of the volume unit of a continuation type being disregarded the level deviation of the right and left at the time of each volume setup. Impedance is taken as impedance connectable with any apparatus as 50k ohms.

Improvement in adoption, reliability, and a feeling of use is expected for 45SD type made from SEIDEN Co. which has established reputation in the switch for volume control of this machine, and an input selector switch. The surface mount type resistor of 1W type of U.S. DALE is adopted as the resistor of a volume control part after much auditions. Since a surface mount type resistor has neither a lead nor the cap for connection in the resistor itself, there is no loss in the portion compared with a resistor usual lead type, and there is no fall of the amount of information. Although appearance is small, since it has 1W type and big capacity, the used resistor can also give big music information certainly. DALE of the manufacture maker of a resistor is a specialized producer of a resistor with leading history also in the world. Many quality resistors high winding resistance or metal clad resistors in respect of sound quality and evaluated even now are manufactured. It is also the part which that in power amplifier or a preamplifier use it, and contributes to the improvement in sound quality also at our company. We are hearing for get the best sound of many resistors. And select the Dale shick film resistor of 1W type.

The high purity 6N copper single track of the diameter of 1.2mm was used for the internal wiring of this machine at all the wire rods. The wire rod is used putting into the tube of the most excellent insulating Teflon. Moreover, high-quality sound unleaded and solder containing golden were used for the solder of a switch portion. In order that a switch part may pass many soldering portions in series, influence on sound quality is a large portion. Sound quality is greatly influenced by this. Our pin jack PZ-102 currently evaluated highly is used for an input-and-output terminal. High performance and high-quality sound are realized by use of the bodies of chromium copper, and the central conductor made from phosphorus bronze.

The input of AT-03-1A is one type. Usually, it is the best for the person of hearing only CD etc. When there is no input selector switch, two points of contact to pass decrease and sound with much amount of information can be realized. As for AT-03-3A, the attenuator position is prepared for the input by three lines at the time of each input. If this attenuator position is used at the times, such as a sudden telephone, it is possible to lower volume of 20dB in an instant. Moreover, also when carrying out BGM reproduction with small volume at night etc., you can use it conveniently. Moreover, two output terminals are prepared in AT-03-3A. Since it is connected inside, these can connect two audiovisual apparatus to an output. It is possible to connect two sets of the amplifier the object for low-pitched sound and for loud sounds with multi-amplifier, or to connect the amplifier for subwoofers.

A chassis portion is intensity frame made from 2mm thickness stainless steel is having adopted . The aluminum panel of champagne gold finish is used. The knob made from an ebony was adopted. The side wood made from cherry tree material is used. Wiring by the shortest distance which uses an extended shaft is carried out. It is considered as quality finish over all the details.

AT-03-1A Specifications
- Form: 28 step volume control attenuator
- Impedance: 50k ohm
- Input system : only one line
- Output system: Only one line
- With no input selector switch
- Outside dimension: 200 (W) 270 (D) 97 (H)
- Weight: 2.2kg

AT-03-3A Specifications
- Form: 28 step volume control attenuator
- Impedance: 50k ohm
- Those with an input selector switch
- Input system: Three lines
- Output system: Two lines
- Outside dimension: 200 (W) 270 (D) 97 (H)
- Weight: 2.5kg

The attenuator unit currently used for AT-03-1A and 3A.
The rotary switch made from SEIDEN Co. and the resistor by DALE are used.