Digital music playback often involves layers of processing, such as upsampling, filtering, and error correction. These steps are designed to improve accuracy from a technical perspective. However, some listeners prefer a more direct path.
With Volumio Preciso, our high-precision dual mono DAC, you can activate NOS (Non-OverSampling) mode. This is more than just a feature. It is a different approach to audio reproduction that emphasizes timing, texture, and signal integrity.
What Happens in NOS Mode?
In standard DAC operation, incoming digital signals (such as a 44.1kHz file) are typically upsampled to higher rates before conversion to analog. This process helps reduce aliasing and simplifies analog filter requirements. However, it can also introduce digital interpolation and pre- or post-ringing effects that subtly alter the music’s character.
NOS mode avoids this process entirely:
No digital oversampling
No FIR or IIR filters
No mathematical reconstruction of waveforms
Instead, the original digital samples are passed directly to the DAC’s output stage. This preserves the natural timing and structure of the audio. While some high-frequency artifacts may be present, many listeners find that NOS mode produces a more natural, coherent, and emotionally engaging sound.
Precision Hardware to Match
NOS mode on the Preciso is supported by an advanced hardware platform:
Dual SABRE ES9039Q2M DACs, configured in true dual mono
Ultra-low phase-noise MEMS clock for accurate timing
OPA1612A op-amp based I/V output stage for low distortion and high linearity
Balanced and unbalanced analog outputs, supporting up to PCM 768kHz/32bit and DSD512
Linear power regulation, LC filtering, and isolated low-noise regulation for each section
For those who prefer a more traditional sound, the Preciso also includes eight selectable digital filters. These allow users to fine-tune their playback experience when NOS mode is not in use.
Why It Matters
NOS mode is not designed to appeal to everyone, and that is intentional. It is for those who want to hear their music without the influence of digital reconstruction algorithms. This mode focuses on preserving signal integrity and delivering a more direct connection to the original recording.
Whether you are rediscovering an old favorite or auditioning a high-resolution master, NOS mode offers a new way to experience music. If you already own a Preciso be sure to update the firmware to the latest version available here
🛒 Want to try it yourself? Learn more about Volumio Preciso and order yours