Vinnie Rossi LIO Modular Audio System

One Box, Many Options

Equipment report
Solid-state power amplifiers,
Digital-to-analog converters
Vinnie Rossi LIO
Vinnie Rossi LIO Modular Audio System

Our hobby of audio comes in a lot of boxes. DACs, preamps, power amps, headphone amps, and their individual external power supplies can easily take up a prodigious amount of domestic real estate. But what if you don’t have the space or flatly refuse to allocate a large proportion of your domicile to fancy metal boxes? The Old School solution was to use an integrated amplifier that combined preamp and power amplifier functions in one enclosure. A modern receiver does an integrated amp one better since it combines even more features, but usually at the cost of sacrificing some sound quality and adding another level of ergonomic complexity that can be counterproductive to serious listening.

But what if you could pick exactly which modules you needed or wanted and have them put into a single enclosure that supported multiple options? One box that can perform many functions—that’s the basic concept behind Vinnie Rossi’s LIO. Depending on which modules are installed, the LIO can be a tube preamplifier, phono preamplifier, a DAC, a headphone amplifier, an integrated amplifier, or any combination of these different options.

Tech Tour
The basic LIO is a chassis with provisions for a maximum of seven plug-in modules and currently offers nine different module options, although several are either mutually exclusive or require other modules to operate. The chassis has a unique power supply that is based not on AC power or batteries, but employs two banks of ultracapacitors to acquire, store, and release operating energy.

Vinnie Rossi calls his new patent-pending power supply “PURE-DC-4EVR.” With two banks of capacitors, one bank is charging while the other is in use, and as the in-use one loses power capabilities, the LIO switches to the second bank while the first gets recharged. This way the audio circuitry is completely isolated from AC power and never directly connected to the charging bank. According to the LIO sales literature, using ultracapacitors will deliver “greater dynamics, tight, more resolved and articulate bass response, more open and extended treble response, effortless sound free of grain, and…a zero-noise black background…due to the lowest possible noise floor.” With a projected lifespan of 500,000 cycles compared to a lithium battery’s 2000 cycles, an ultracapacitor bank should last far longer than any set of batteries. Ultracapacitors also have an extremely low internal resistance of less than 0.003 ohms per cell, which according to Rossi, “delivers higher DC current than any other storage device.”

LIO has what Rossi calls “an optimized signal path” that uses a unique PCB motherboard that is a backplane for optimally routing signal and power supply traces. Connections between the various modules can be measured in inches rather than in feet. With certain LIO configurations the only cables you will need will be for your speakers or digital and analog input connections—as the connections between DAC or phono to preamp, or preamp to power amplifier or headphone amplifier, are handled by the internal signal traces.

Although you could configure a LIO as a strictly analog device, most prospective owners will probably want to include the DSD/PCM DAC board option ($895). This module accepts TosLink optical, BNC/SPDIF, and USB digital inputs. This dual-mono design uses one AKM AK4399 D/A chipset per channel and supports PCM up to 384/32 and DSD128. The DAC has both linear-phase and minimal-phase PCM filters, as well as a 180-degree polarity switch, all of which are selectable from the remote handset. The DAC includes on-board re-clocking circuitry, ultra-low-noise linear voltage regulators, and an asynchronous USB interface that features galvanic isolation. Basic specifications list the output voltage of 2.0 volts RMS and an output impedance of less than 100 ohms; the signal-to-noise for the DAC module exceeds 100dB. And if another digital specification or format becomes available (such as Meridian MQA) the LIO can be fitted with a newer DAC module that can handle the new specs.

The LIO mm/mc phonostage ($895) has three separate inputs, two for moving-coil and one for moving-magnet cartridges. With an all-discrete Class A JFET topology with zero feedback in the gain and RIAA stages, the phonostage delivers 40dB gain for the mm input and 60dB gain for the mc inputs. Audiophiles with multiple cartridges that require their own impedance settings can add a neat feature—remote cartridge loading via a companion board ($495). This module has 256 settings with loads ranging from 5 to 2000 ohms. The RCL also has two preset load settings for your most frequently used cartridges.

To turn the LIO into an integrated amp, all you have to do is add the MOSFET amplifier module ($895). With a Class AB design capable of 25 watts into 8 ohms, 45 watts into 4 ohms, and 65 watts into a 2-ohm load, the LIO amplifier should be able to drive most 90dB+ sensitivity speakers with no issues. (But don’t expect this particular LIO power amplifier to drive your 2-ohm Apogee Scintillas to louder than background music levels.)

According to Vinnie Rossi, we can expect other amplifier modules in the near future, including both a single-ended, Class A, low-power design and possibly a high-power Class D module. As with all LIO products, all amplifier modules are covered by a ten-year warranty.

If you spend any time listening to headphones, the LIO headphone amplifier module ($695) is a must-have addition. Available with either single-ended TRS or balanced 4-pin XLR connectors, the headphone amp can produce either 1W into 32 ohms in single-ended or 2W into 32 ohms in balanced output. With an output impedance less than 1 ohm and a choice of either 0 or 12dB of gain, the headphone amplifier should be able to handle almost any ’phones. And if you have something that is especially hard to drive, LIO offers an accessory cable that lets you drive headphones from the MOSFET power amplifier’s outputs.

The LIO Analog input board ($295) provides three analog inputs for the LIO. Input switching can be controlled via the LIO’s front panel, supplied remote, or soon-to-be-released smartphone app.

The LIO offers several options for volume controls. One is a film-resistor stepped attenuator ($395) with 64 discrete, 1dB volume steps, and dual-mono switching so that left/right balance can be adjusted with no additional parts in the circuit. This stepped volume can be combined with the LIO Tubestage ($895), which is a current-gain voltage follower stage that mates with the resistor volume control and analog input board to make a complete active tube preamplifier. The Tubestage uses a pair of E88CC dual-triode tubes in a single-ended Class A design that features constant current source and auto-biasing with no AC-DC converters used.

A second, alternative volume control ($1495) is available for those who want the ultimate in transparency. It employs an autoformer made by Dave Slagle of Intact Audio. This volume control is a 100-percent passive device with a 64 steps in 1dB increments. It is also a true dual-mono design that permits balance adjustments without having to use any extra parts or circuitry.

The final module is the Line Output module, which you will find on every LIO as part of the base unit. This module contains three sets of stereo outputs. Two of the three are variable outputs controlled by whichever volume control you’ve chosen, while the last is a fixed output. If you choose to assemble a LIO without a volume control, the variable outputs are not used and all three outputs will be fixed level. If the LIO is set up as a phono preamp, three fixed line-level outputs is a useful option.