LH Labs Vi DAC Tube Pro.
No-Compromise Architecture That's Fully Balanced and Dual Mono
Vi DAC uses a fully balanced architecture throughout its entire circuit, which results in the best noise rejection possible, and is the most natural way to cancel distortion. In addition, it uses a dual mono design, implementing dual ESS Sabre DAC chips, a dual separated power supply and a dual analog output stage.
Interchangeable fully-balanced Tube output stage
Optional Hybrid Solid-State/Tube Output Buffer-
A DAC has two principal parts: the digital processing stage, and the analog output stage. Vi DAC’s digital stage utilizes an advanced, proprietary solid-state design first implemented in our Da Vinci DAC.
The analog stage is where the magic happens. Vi DAC’s solid-state analog stage is both musical and controlled at the same time. We’ve also designed an optional tube output buffer for those aficionados who love the warm and liquid sound of tubes.
The World's Most Versatile DAC
Vi DAC's versatility is unmatched. It features five digital inputs: one USB, one TOSLINK, one AES/EBU, and two S/PDIF. it outputs at line level through one pair of RCA single ended outs and one pair of XLR balanced outs.
Advanced 64 Bit Volume Control
In the past, attempts to engineer digital volume attenuation has been panned by audiophiles due to its very obvious "digital-ness." Analog volume control has been preferred, though it also presents a problem because of the noise that it generates. We've taken a different approach to volume control with our advanced 64 bit attenuation circuit, which uses an ultra-high resolution, zero noise, bit perfect mechanism.
In the case of computer-based playback via USB, Vi DAC's volume attenuation circuit replaces the computer's volume calculations with its own, ensuring that your music remains bit perfect all the way through the conversion process. This way, it ensures that no information is lost before Vi DAC gets the data.
Automatic Digital Volume Control Shut Off
If you want to use the analog volume control of your preamplifier,set Vi DAC's digital volume attenuation circuit to -0dB, which completely bypasses the digital volume control circuit.
Individual Channel Control
In order to keep the digital music bit perfect, we've designed Vi DAC so that once it's volume is set to -0db, you can control the individual channels' attenuation settings to adjust balance.
User-Selectable Digital Modes
Most DAC aficionados understand the importance of digital filters. One of the major functions of digital filters is to remove the digital artifacts that the digital-to-analog conversion process adds to the signal.
Vi DAC features several user-selectable digital modes that go beyond digital filtration. These modes were developed specifically to Vi DAC (all of our products feature digital modes specific for their application even though they may share the same name product to product). These modes not only change digital filtration settings, but also the digital PLL windows of the internal DAC IC, the re-clock jitter removal circuit, along with other hardware installed into the DAC.
Users get the benefit of continuous upgrades to their digital modes through firmware releases.
TCM (Time Coherence Mode) uses LH Labs' minimum phase digital filter and time optimization algorithm, which removes all PRE-ring from the converted signal and realigns the impulse response. This presents the listener with a more well-defined and natural soundstage. In short, this mode is optimized for time domain response.
FRM (Frequency Response Mode) uses a slow roll-off linear digital filter and frequency domain optimization algorithm to provide a smoother and clearer sound with even lower THD+N in the high frequencies. The IMD in the higher frequencies is lower because of frequency response and high frequency artifact optimization.
FTM (Femto Time Mode) minimizes the bandwidth of the DAC IC's digital PLL, providing even better jitter performance and better sound quality. Available for ALL of our femto clock equipped DACs.
SSM (Stable Streaming Mode) is designed to optimize Vi DAC for streaming music. This mode combats two most important issues of streaming your music: time-fluctuated high jitter music content, and compressed roll off of high frequency harmonics. With SSM, Vi DAC will restore your streaming music's timing using our patent-pending three layer buffer. Expect a richer sound in the mid and high band frequency range.
Ultra-quiet Linear Power Supply
Vi DAC's linear power supply employs 26 high quality regulators, including 4 discrete shunt regulators, making it among the quietest linear power in the industry. In addition, the power circuit is completely isolated from the digital and analog circuits, preventing mechanical noise from the transformer from entering the signal path.
Proprietary Three Layer Elastic Buffer
To ensure computer speed fluctuations don't smear your music, we've developed a proprietary (and patent-pending) Three-Layer Buffer similar to the buffering technology many of today's high-speed computers employ. This is the first time such a design has been applied to audio.
Bipolar Instant Power Technology
To address the issue of energy during power hungry times, our output stage uses an extremely low output Z bi-polar power supply, which keeps at least twice the rated power in reserve just in case you want the cannons in Tchaikovsky's 1812 Overture to feel like they're taking aim right at you.
Dual 2015 ESS SABRE9018AQ2M DAC Chips
Vi's DAC's design has always been to utilize ESS' Sabre 9018 DAC microchip for its digital to analog conversion. New for 2015, ESS has released the 9018AQ2M, which boasts even better harmonic distortion characteristics than its predecessor, as well as a lower noise floor and greater dynamic range. You have the option to utilize this new chip if you so choose.