Sonnet Pasithea DAC

No oversampling digital filter stands in the way of music, giving you near-perfect time-domain impulse with excellent phase response, helped by frequency response that doesn't truncate abruptly confined to obeying Nyquist laws.

But don't let Sonnet's unprocessed lack of digital additives detract from its technical prowess – Ruijtenberg's and Co-Founder Lion Kwaaijtaal's technique of splitting a datastream's Most-Significant Bits (MSB) from its Least-Significant Bits (LSB) and decoding them separately for extreme dynamic range is proprietary.

With a forward correction technique first employed to great effect at Metrum Acoustics, Ruijtenberg repeated the trick at Sonnet. Each of Pasithea's eight SDA-3 DACs contains an FPGA that separates the LSBs from the MSBs. Then, Pasithea increases the level of LSBs and decodes them as if they were MSBs, routed to the same, optimal top half of the SDA-3's resistor ladders.

In this way, Sonnet's LSBs are not forced to be decoded at the nominally low bit level where they struggle and are otherwise swamped by switching noise. Splitting and boosting LSB level to be the same as the MSBs – before the former's very loud output is attenuated post-decoding and sewn seamlessly back together to form the whole signal at the right volume – yields an extremely linear DAC.

Ruijtenberg's proprietary take led to a DAC that resolves a digital signal linearly down to a staggering -160dB, effectively making Pasithea capable of achieving greater than 24 bits of dynamic range without the use of DSP trickery like dither or noise-shaping. 

This additive-free approach yields a sense of real quiet and realistic space between notes, as well as top-to-bottom phase correctness. Micro and macro-dynamics snap into place helped by the slew rate prowess of Pasithea.

This kind of natural transparency is preserved by Sonnet's special volume control, achieved by adjusting the reference voltage of its SDA-3 DACs instead of normal attenuation, to preserve its resolution no matter how low or high its pre-amp is set.

The extremely analog nature of Sonnet's operation extends to a jumper switch that lowers output by -10dB for use with downstream amplifiers that suffer from excessive gain.

Indeed, with a DAC as capable as SDA-3, the demands on Pasithea's analog section are higher than ever. Direct-coupled outputs from Pasithea also means frequency response extends down to DC for deep, natural and taut bass plus all its harmonics.

Similarly, the extremely low output impedance of Pasithea's output stage means that it'll drive any downstream amplifier such as Mass-Kobo capably without unwittingly forming a high-pass filter like some oriental R2R DACs – thus yielding an accurate, extended, low-frequency performance expected of a reference piece of equipment.

Clever Dutch decoder design continues to keep discrete R2R DACs at the cutting-edge of digital audio this decade, a large portion of which can also be enjoyed on the Morpheus here. Check out all of Sonnet's products here, or our other DACs here.