Soulnote D-2 Digital to Analogue Converter

The D-2 is Soulnote’s Digital to Analogue Converter from their middle range of products – Series 2

Step up from Series 1 to Series 2 and the first thing you will notice is the larger casework, the D-2 stands at 160mm tall, 5cm taller than the D-1N

Series 1 models all have the front panel milled from aluminium, step up to Series 2 and that continues around the sides, the build quality is first rate and the D-2 weighs in at 17kg. The top plate of the D-2 ‘floats’ on the chassis, it is not firmly attached or screwed down. Soulnote have always argued that the case construction is just as important the to overall performance as the actual components that make up the product itself.

The D-2 offers 5 digital inputs with USB-B, 2 x AES/EBU and 2 x RCA. There are both RCA and XLR analogue outputs, there is also a word clock input – Soulnote make a Clock Generator, called the Z-3 which serves as a great upgrade for the D-2

There is also switches on the rear to choose between FIR oversampling and a non-oversampling mode (PCM only), there is also a mono/stereo switch on the rear as well, you can double up with 2 and run a pair in dual mono mode.

In an industry first the D-2 utilises 4 ESS ES9038Pro chips in its design (2 per channel) to ensure it delivers the best possible performance.

When partnered with a Melco the presentation is vivid and vibrant, but there is a real sweetness and allure to the music, you get a wonderful sense of air and space around everything and it seems to make everything sound real and almost tactile when are sat listening to it, partnered with A-2 it makes for a seriously strong combination.

The DSS uses the LMX2594 from Texas Instruments

D/A converter formats that recreate the required master clock from standard clocks typically use a DDS (Direct Digital Synthesizer). The performance of external clock generators in this format guarantees extreme frequency accuracy (e.g. how many seconds of deviance will occur over tens of thousands of years), but jitter (fluctuations in waveform width arising in the clock) and the resulting phase noise are highly dependent on the performance of the DDS. By convention, audio equipment generally uses DDS-specific ICs with 10 ps (picosecond) jitter functions, but the D-2 is the first device to use Texas Instrument’s PLLatinum™ RF LMX2594 synthesizer for an audio DDS. The LMX2594 synthesizer was developed for radars and measurement instruments and boasts the world’s highest specifications with an efficiency index of -236 dBc/Hz and jitter of 45 fs (femtosecond, 1/1000 of a picosecond). This ultralow jitter DDS results in an overwhelmingly clear and deep spatial presentation when inputting the high-precision external clock and using the built-in TCXO.

Supports 10 MHZ external standard clock inputs

Using a DDS with jitter functionality that surpasses quartz means that the D-2 comes with 10 MHz external standard clock inputs, a SOULNOTE first. The internal clock relies on a high performance TCXO boasting stunning phase noise (-121 dB at 10 Hz offset). It also features a high frequency relay with mechanical contacts to avoid additional jitter from the IC when switching between the internal clock and an external clock generator. The internal clock power supply shuts off and vibrations stop when using an external clock generator, this way removing any risk of mutual interference.

2 ES9038PRO circuits are employed in each channel for the upper and lower differential complimentary inputs in this SOULNOTE original fully symmetric non-NFB discrete amplifier, completely driving the initial stage in the non-NFB differential amplifier. The IV circuits are extremely simple IV circuits with only one resistor to eliminate TIM distortion that can be so problematic with feedback type IVs. With an extremely powerful 120 mA, the two ES9038PROs are used in each channel to allow natural music playback bursting with life. The ES9038PRO operates in synchronous mode to obtain the highest sound quality.