Analysis of YAMAHA DSP-A1 AV Amplifier

When DTS software is launched in large quantities in the new wave of home theater, YAMAHA has launched a top-level AV amplifier with DTS/AC-3 (decoding) function, DSP-A1. The appearance design still inherits the style of YAMAHA's top models in the past. The huge body, iron-gray heavy metal panel, and noble wood guards on both sides show a refined and luxurious taste. It is 19.05cm tall, 2cm taller than DSP-A3090, and weighs 25kg, which is 1.5kg heavier than A3090, and looks more impressive.

The panel design is also simple and elegant. Except for volume adjustment, source selection switch, power switch and Tape 2 Monitor switch, all function keys are designed under the sub-panel. If you want more practical operation, you still need to rely on the remote control, which is more convenient. The remote control also has a main and sub-panel design. The complex and rarely used function keys are designed under the sub-panel. The control keys are spaced in different shapes, making it easy for users to get started; it also has a learning function and can control other AV equipment. In addition, the buttons have night light display. It is also very convenient to use in the dark. YAMAHA has put a lot of thought into its design.

The output/large terminal on the back panel is basically the same as that of DSP-A3090. There are 5 sets of pure audio input terminals, 2 sets of pure audio output terminals, 5 sets of AV input terminals (including S terminals), and 3 sets of AV output terminals (including S terminals). It can connect 4 sets of pure audio equipment and 5 sets of AV equipment. The special feature is that there is also a set of 5.1 channel input. If there is any new surround system in the future, users do not need to change the machine, just buy a decoder. In terms of digital terminals, there is 1 set of Dolby AC-3 RF input, 3 sets of coaxial input, 5 sets of Toslink optical input. 1 set of Toslink optical output, and each set of input can automatically identify whether it is a PCM, Dolby AC-3 or DTS signal. Each channel has a pre-stage output terminal, which can be upgraded with a more advanced power amplifier. All terminals are gold-plated to prevent oxidation. The circuit of DSP-Al can be said to be made with the latest technology.

The Dolby AC-3 decoding part uses the YSS249 chip developed by YAMAHA itself. This chip operates at 24 bits, has a very high precision, and can transmit information at a rate of 640Kbps. The DSP sound field and various EQ functions are also completed by the YSS214 DSP chip designed by YAMAHA itself. This chip also operates at 24 bits. The YSS214 was originally used in professional equipment such as sound sources and communications. The DTS part uses an independent circuit board, which is located above the digital circuit. The outer cover is shielded by a thin metal plate. In addition to isolating noise, it also has the effect of enhancing heat dissipation. The DTS decoding uses the DSP56009 chip produced by Motorol. This chip operates at 24 bits and has an operating speed of up to 93Mhz. The A/D conversion IC is Asahi Kasei's latest product AK5391, which is 24 bits l28 times sampling, with a dynamic range of 113dB and an SN of 113dB; the D/A conversion IC is also Asahi Seiki's latest product AK4324. This IC has a built-in 24-bit 8-times sampling filter, which can correspond to 24-bit 96KHz signals,

with a dynamic range of 105dB. Since this DAC is a stereo design, this machine uses a total of 4. In addition, the power supply of this machine is worth mentioning: the EI transformer with low magnetic leakage and copper foil weighing 8.5kg, plus 2 Nichicon Gold Tune large filter capacitors, with a total value of up to 54000uF, can lay a solid foundation for the power supply of this machine. The original manufacturer claims that the output power of the main, center and surround channels is 110W (6 ohms) per channel, and the front surround channel is 35W (6 ohms), which can definitely produce large dynamic sound effects.