The AK4493EQ adopts the company's improved VELVET SOUND architecture, achieving even higher performance than the AK4490EQ by optimizing the circuit design. The AK4493EQ also adopts AKM’s original dedicated audio process as its flagship DAC, the VERITA AK4497EQ. This process, according to the Japanese company, has "improved the original acoustic sound expression that can be found in the sound strength and the data amount." (it probably made sense in the original Japanese...) In addition, the AK4493EQ was design to correctly translate high-resolution sound sources, accepting up to a 22.4MHz DSD input (DSD512) source.
The AK4493EQ will be introduced during CES 2018, where a listening demonstration will be available, and more detailed information will be provided. For now, AKM confirms that the improved VELVET SOUND architecture is founded not only in the circuit design, but also in the LSI manufacturing process, developed by AKM exclusively for these audio devices. By adopting this process, the new AK4493EQ is supposed to improve low frequency noise performance and electric margin.
According also to AKM, the 32-bit processing is responsible for improvements in the Impulse Response (IRD) filters, resulting in a more detailed and natural signal wave. A new harmonic sound filter was added to the existing five filters found in the previous generation device, now allowing users to select among six different digital filters, according to their audio and system preferences.
The AK4493EQ's higher performance, surpassing even the brand's best-selling AK4490EQ DAC, is translated into the lowest achieved distortion so far, with -113dB THD+N and 123dB S/N in stereo mode, or 126dB in Mono. In addition, AKM implemented even higher over-sampling using what the company calls OSRD (Over Sampling Ratio Doubler), to greatly reduce out of band noise.
Designed to better support high resolution audio sources, the new AK4493EQ is now able to support up to a 22.4MHz DSD (Direct Stream Digital) input, which means octuple-rate DSD, or 512 times the sample rate of a CD. The digital input also supports up to 768 kHz PCM.