Yamamoto Sound Crafts AT-03-1A 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.

format	28-step volume adjustment attenuator
impedance	50kΩ
Input	Only 1 system
Output system	Only 1 system
Input selector switch	without
External dimensions	200(W) 270(D) 97(H)
weight	2.2kg

Perhaps because of the extremely simple composition, I have the impression that it has a smooth sound. However, the tone and range are similar to Yamamoto Acoustics' other products, with a soft and warm tone with a center of gravity in the midrange. The piano has a round sound that makes you feel the warmth of wood, and the violin and classical guitar also have a woody warmth. The timpani and bass have a light tone that waits for just the right amount of stickiness and stretch, and does not become too heavy. When nature sounds are played, the sound of the waves, the chirping of birds, and the chirping of the lark are mellow and comfortable while having a fineness that allows you to see the details. The audible volume is slightly lower than that of Amtrans and Phasemation.