Yamamoto Sound Crafts AT-03-3A Top Quality Attenuator Unit

In addition to the overwhelming amount of information and rawness in the high frequency range peculiar to passive attenuators, it has a soft and warm tone. There is no shortage of bass and a sound that is light, light, delicate, bright and comfortable

By reducing the number of circuits through which the music signal passes, the freshness of the sound increases and the sound quality can be improved. The attenuator part of the AT-03-1A and AT-03-3A uses a volume adjustment function called an L-type that switches a 28-point resistor. The L-pad type requires only two resistors to enter the signal source, and the sound quality of the resistors is minimized. Losses caused by passing resistors are minimized by the use of surface-mount resistors, and almost no noise is generated during contact switching.

The step spacing of each switch point can be adjusted from 0 dB to -38 dB in 2 dB steps, allowing for fine adjustment. In addition, the minimum volume can be reduced to -65 dB, and any level can be adjusted. The level deviation between the left and right sides at the time of each volume setting is effectively within 0.2 dB, and we have succeeded in suppressing the difference between the left and right levels, which is a weak point of continuous volume units, so small that it can be ignored. The impedance is 50 kΩ, which is an impedance that can be connected to any device.

The volume adjustment switch and input switch of this unit use the well-established 45SD type made by Seiden Co., Ltd. to improve reliability and usability. After many auditions, we have adopted a 1W type surface-mount resistor from DALE of the United States as the resistor for the volume adjustment part. For the internal wiring of this machine, we used 1.2mm diameter high-purity 6N copper solid wire for all wire rods. The wire rod is used in Teflon tubes, which have the best insulation.
For the internal wiring of this machine, we used 1.2mm diameter high-purity 6N copper solid wire for all wire rods. The wire rod is used in Teflon tubes, which have the best insulation.

The dial and feet are made of ebony.

format	28-step volume adjustment attenuator
impedance	50kΩ
Input	Only 3 systems
Output system	Only 2 lines
Input selector switch	And
External dimensions	200(W) 270(D) 97(H) mm
weight	2.5kg

Passive attenuators, which do not have an amplification circuit like a preamp, did not have much hope for low frequencies, and I thought that the sound would be lighter in the mid and high frequencies, but I didn't feel that there was a shortage of bass as much as it was said. The sharp rise is sharp, the sound of the space is clear, the separation of the instruments is good, and the atmosphere of the site is conveyed. You can feel the flow of air from the brass instruments playing, and the depiction of the female vocals that are firm and extend to the high notes is also vivid. There is no feeling of thinning the sound by reducing the volume. Unless you are very particular about the deep bass range, I think the bass is necessary and sufficient.