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.
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.
Ergonomics and Installation
The primary design intent behind the LIO is its ability to be configured in a variety of ways to permit an impressive—and perhaps unprecedented—degree of customization and integration. Vinnie Rossi can assemble the LIO into so many different combinations of components that any prospective owner should examine his own wants and needs carefully to come up with a customized set of modules that will best serve him. (Of course, you can always change your mind.)
My review unit consisted of the following modules: the autoformer volume control, DAC, headphone amplifier, power amplifier, analog inputs, and analog outputs. The LIO comes in a black anodized or silver chassis with black or silver knobs. I chose black on black. The total cost of the LIO under review was $6770.
I had to make some either/or choices in my LIO configuration because (as mentioned) some modules are mutually exclusive. For instance, if I had wanted to have the tube linestage, it would have required substituting the stepped volume control for the autoformer. If I had wanted the phono board and its companion variable impedance board, I would have had to remove an installed board to accommodate those.
One-box solutions such as the LIO or more traditional integrated amplifiers are best suited for installations where space is at a premium and there’s a relatively short distance from your primary input selector to your speakers. Desktop and nearfield setups are both ideal for the LIO, and that was how a majority of my critical listening was done. Even with my lowest-sensitivity monitor, the Aerial Acoustics 5B (84dB), I was able to achieve satisfying volume levels from the LIO amplifier section for nearfield listening.
The finite space limitations of any sized box, save for one piloted by Dr. Who, can be almost magically surmounted due to the LIO’s flexibility—in the future I plan to try out the LIO as a dedicated phono preamplifier. To accomplish this I’ll turn off the power amplifier module and install the phonostage module. I’ll then have a phono preamp that has its own dedicated headphone output, as well as both fixed and variable line-level outputs. Try doing this kind of functional about-face with any conventionally configured component. By contrast, a LIO owner could easily have a small collection of different modules on hand to swap out, depending on current requirements.
Setup was as easy as it gets. I attached a USB cable to the LIO’s DAC, a pair of RCA cables from LIO’s variable outputs to my subwoofer, a pair of speaker cables to my speakers, an AC cord, and I was done. Later I added an external DAC via one of the analog inputs, as well as an Astell&Kern AK240 portable player.
Considering all of the component’s functions, the LIO’s front panel is remarkably minimalist. On the left side are two pushbuttons, one for power and the other for activating the power amplifier module. To the right of these is a knob that controls the input selection. The center of the LIO has an LED display flanked on the right by a row of LEDs that register volume level, load (for phono cartridges), frequency (from digital sources through the DAC), voltage (the in-use ultracapacitor charge level), and dark (to turn off the display). The volume control knob is to the right of the row of LEDS, followed by the headphone output connection.
The LIO comes with a wand-shaped remote that features chromed end-caps and a solid-feeling metal body. It duplicates all the functions on the front panel and even adds a couple more, including a polarity-reversal switch and a DAC filter switch. (The LIO uses the same codes as Vinnie Rossi’s Red Wine Audio products’ remotes, so if you happen to have one of those remotes, you can also use it with LIO.)
I do have a few small ergonomic quibbles. The principal one is the single-ended headphone output connection. I’ve seen this connector-type before, and I will probably see it again because it is a highly regarded quality part. But it is a bother to use because, unlike most single-ended headphone connections, it requires that you push in the red catch above the insertion point to release the headphone. I’m still working on a way to do this successfully with only one hand. It feels like I’m up against the audiophile equivalent of a childproof bottle. Two-handed headphone disconnection gets old quickly, especially if you use and change cans as often as I do.
Also, the LIO headphone’s native output is best suited for less efficient, medium- and high-impedance ’phones. With headphones such as the AKG K-7xx, Audeze LCD-2, and HiFiMan HE-560, the background was silent. But with models that had sensitivities greater than 96dB, I could hear some background hiss from the LIO’s headphone amplifier. If you intend to use more sensitive ’phones, Vinnie Rossi offers a pair of jumpers that knock down the gain by 12dB. (To install the jumpers you do have to remove the LIO’s top-plate.)
Depending on your tolerance for occasional clicks, the LIO’s changeover from one ultracapacitor bank to the other may or may not be bothersome. Approximately every 20 to 30 minutes the LIO will click when it switches banks. The click isn’t too loud, but you will notice it.
My final ergonomic quibble is that when you turn on the power amplifier module, it takes about ten seconds for it to become active, during which time the LIO will not be available for use. Of course you can just leave the power amplifier module on all the time, but that will drain your ultracapacitor banks more quickly and cause the LIO to recharge more often, even while idling.
Currently, there is only one tried-and-true way to completely eliminate noise from a system—eliminate the signal, because without a signal, there is no noise. Obviously this solution won’t work in the real world, where the whole point is to have a signal. The next best thing to no noise is a signal-to-noise ratio greater than 100dB. The LIO does just that with a >100dB published S/N figure. But internal signal-to-noise is only part of the story; a component needs a quiet, well-isolated power supply, as well. With its ultracapacitor, the LIO has pushed power supply design to the outer limits.
One of the tests I usually run with new gear is something I call my “high AC line noise test.” It involves plugging in a Pioneer LaserDisc player and turning it on. This particular player’s power supply dumps a whole lot of noise into the AC line, which I can hear via my Noise Sniffer AC noise-detection device. I then listen to the component under review with the LD player plugged in, and again with it unplugged from the AC line. With some components I can hear the degradation introduced by a noisy AC line in the form of audible hum levels and spurious noise, while with others no audible differences are apparent. The LIO proved to be completely insensitive to AC power vagaries.
My new house has terrible power—usually running at between 122 and 125 volts with a high level of line noise. To counteract that noise, all my components have some kind of AC power filtration between them and the wall. In my nearfield system, I use a PS Audio Quintet (now replaced by the Dectet) to filter the AC power. I tried the LIO connected through the Quintet and then plugged directly into a wall outlet—once more I could hear no audible differences. If your power is flakey, the LIO is an effective way to lower the effects of AC vagaries to such an extent that, regardless of time of day or season, your system will have the same low level of externally induced noise.
I used a number of different speakers with the LIO in my nearfield setup, including the Audience 1+1, ATC SC-7II, Role Audio Kayak, and Aerial Acoustics 5B. The LIO amplifier had adequate juice to drive all of them without issues. Also, with even the highest-sensitivity speaker, I heard no hiss, hum, or extraneous noise with my ear practically resting on the tweeters.
I was impressed by the LIO’s overall level of finesse and transparency. The Autoformer volume control delivered accurate and repeatable levels with no readily apparent colorations whatsoever. And while some audiophiles will feel the need to add tubes via the stepped-resistor volume control coupled with the tube linestage module, I found the sound using the autoformer volume module was as close to absolutely neutral as any device I’ve heard.
As I look through my listening notes on the LIO, I notice that most of my comments were not about the sound itself, but about the music, and I consider that a good thing. The LIO consistently delivered music in a way that focused on the music. I was far more aware of the subtleties of microphone placement and the recording engineer’s reverb choices than of any sonic peculiarities unique to the LIO itself. But unlike many “neutral” components I’ve reviewed in the past, the LIO doesn’t sound matter-of-fact or mechanical. Instead it got out of the music’s way, and stayed out of the way.
A good part of the LIO’s relative sonic invisibility can be attributed to its noise-free character. It’s easy to listen into mixes, even thick, multi-element confections such as Fences’ latest release Lesser Oceans. Listening to a Hi-Fi stream from TIDAL via Roon and Amarra sQ+, I could hear deep into the opening tune on Lesser Oceans, “Songs About Angels,” and detect the multiple instruments subtly doubling (and tripling) the background vocal melody lines.
Another example of the LIO’s high level of transparency was that I could hear the improvements that Amarra sQ+ made on the TIDAL app’s sound quality. While subtle, its effect was pervasive, rendering the presentation more revealing and incisive. I also have started using Roon, which did not benefit sonically from being used in conjunction with Amarra sQ+ unless I had need of the sQ+’s EQ adjustments. Roon sounded especially good when playing back my 128x DSD live concert recordings through the LIO.
Using the LIO for headphone listening provided the same level of high-quality sound, so long as I paid some attention to matching the headphones to the LIO’s headphone amplifier. Since the LIO only has a jumper wire for reducing the overall gain, if you regularly go from high-sensitivity in-ears to low-sensitivity headphones you may find yourself spending part of your listening sessions removing and then reattaching the LIO’s top plate so you can access the jumpers. With “average” sensitivity-and-impedance headphones, including the AKG K-7xx, Sennheiser HD-600, Beyer Dynamic DT-880 250, Beyer Dynamic DT-990 600 ohms, Audio-Technica ATH 900X, or Audeze LCD-2, the LIO had no issues sans jumpers. But with any high-sensitivity earphones including the Sennheiser Momentum on-ear, Oppo PM-1, Oppo PM-3, Westone ES-5, and Jerry Harvey Roxannes, the LIO’s headphone amplifier needed the jumpers if I wanted to hear music emerging from silence.
To see how transparent the LIO was, I used the ifi micro iDSD as both a USB-to-SPDIF convertor and a full DAC into the LIO. (To clarify, both signal chains used the ifi micro to do the USB-to-SPDIF conversion, but one signal chain went straight to the LIO’s DAC and then its analog stage, while the second went through the ifi micro’s own DAC and analog circuits before being connected to the LIO’s analog section.) It didn’t take long to hear differences once I matched the output levels between the LIO’s DAC and the ifi micro (via its front panel volume control). The ifi analog feed had a drier, more brittle top end compared to the LIO. And while both feeds had equal soundstage width, the LIO had more convincing depth and three-dimensionality, in addition to better micro-dynamics. There was one area in which the ifi excelled: It could be adjusted to work with a wider variety of earphones.
If I had to identify any “weak links” in the LIO, one would be the headphone amplifier’s gain flexibility and the MOSFET power amplifier’s low power-output capability. Many speakers in medium or larger rooms will simply need more power than the LIO amplifier’s 45 watts into 4 ohms can deliver. Fortunately, due to the LIO’s modular design, it should be quite easy for Vinnie Rossi to design and deliver a dedicated high-sensitivity headphone amplifier.
Another development in the works is a new power amp. According to Rossi, “We are also working on a more powerful, external Class AB ultracapacitor-powered MOSFET power amp. It would be in an enclosure approximately the same size as the LIO, and the LIO could be stacked on top of it. It hopefully will be able to make a debut at the RMAF 2015 show, and should offer approximately 100Wpc into 8 ohms, 200Wpc into 4 ohms, and more into 2 ohms.”
The history of audio is populated with manufacturers who have offered solutions for the problem of too many separate components in the audio signal chain. Vinnie Rossi’s LIO is different because its modular design allows for and anticipates technological change. The LIO’s ability to become almost any combination of components makes it unique. Also, by merely placing the needed modules into the LIO’s chassis, an owner can easily convert the unit from one function to another.
Sonically I found the LIO to be a highly transparent and extremely low-noise component that allowed the music to pass through it unscathed. While I can’t discern what percentage of this can be attributed to the LIO’s ultracapacitor power supply as opposed to its autoformer volume control, I do know that the final result was as clean, clear, and uncolored as any component I’ve heard.
If you need to downsize or have an environment that will not tolerate a multiplicity of boxes scattered about, the LIO is a clever way to save space while retaining superb sound quality and upgradeability. Also for anyone who is assembling a compact yet versatile, computer-sourced, nearfield monitoring system, the LIO is an attractive option. Finally, for those unfortunates whose AC power is as impaired as mine, the LIO offers an elegant way to eliminate your power’s pernicious effects. Yes, Vinnie Rossi’s LIO solves a lot of problems elegantly with one simple box.
SPECS & PRICING
Output voltage: 2V RMS
Output impedance: < 100 ohms
SNR: > 100dB
Playback bit rates accepted: (PCM) 16, 24, 32
Playback sample rates: (PCM) 44.1, 48, 88.2, 96, 176.4, 192, 352.8, and 384kHz (DSD) DSD64, DSD128 via DoP
Power amplifier module
Output stage: Class AB MOSFET
Power output: 25Wpc into 8 ohms, 45Wpc into 4 ohms, 65Wpc into 2 ohms
Gain/Load (mm): 40dB/47k
Gain/Load (mc): 60dB/16 load settings from 26 to 400 ohms
Output impedance: < 100 ohms
RIAA: Passive filter between two discrete, Class A JFET gain stages
Voltage gain stages: Class A JFET, no feedback.
Included tubes: JJ E88CC (matched pair)
Accepted tubes: 6922/E88CC, 6DJ8/ECC88, 7308/E188CC, 7DJ8/PCC88, 6N23, 6H23, 6N11, and 6GM8
Output impedance: < 200 ohm
Frequency response: 10Hz–110kHz (+/-0.5dB)
Gain: Unity (0dB)
800 Main Street, Suite 125
Holden, MA 01520
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