Like the M-DAC, the M-DAC+ incorporates the ES9018 Sabre Reference 32-bit DAC chipset, still widely regarded as the finest available. This is surrounded by exceptionally well-specified circuitry that puts other similarly priced DACs to shame, including a proprietary, discrete master clock to minimise jitter, coupled with extensive time domain isolation. A JFET Class A output stage ensures that the audio signal, following conversion from the digital domain to analogue, is of the highest quality.

As digital audio technology has progressed, the importance of the characteristics of reconstruction digital filters has become more appreciated. Like the classic M-DAC, the M-DAC+ features user-selectable filters for optimal listening and measurement modes, in addition to more conventional types for easy comparison. These filter settings allow the user to tune performance to suit his or her preference, depending on system configuration, digital file quality and musical taste. The M-DAC+ inherits seven filter settings from the M-DAC for PCM files and adds four more for DSD playback, allowing the user to optimise the noise floor to suit the performance of the source file and the bandwidth of associated equipment such as amps and speakers.

Another important change relates to the power supply, which has been upgraded and is now incorporated within the M-DAC+’s chassis (hence its slightly taller and deeper case compared to the classic M-DAC). A precision-wound toroidal transformer uses multiple windings to feed separate analogue and digital rectification stages. From there, multiple power supply sections feed the necessary voltages to each area of the DAC, keeping any crossover interference to a minimum. The result is the highest performance power supply Audiolab engineers have yet specified for a DAC, and its contribution to the M-DAC+’s enhanced sonic performance is significant.