AudioControl Rialto 400 Amplifier/DAC
AT A GLANCE
Plus
High-performance Wolfson Audio WM8671 DAC handles signals up to 192 kHz/24-bit
AccuBASS designed to restore depth to compressed audio sources
Automatic input switching
Minus
Runs hot
Lack of front-panel controls may be problematic for some installs
THE VERDICT
This terrific amplifier and DAC solution improves sonics in a small package.
The quest for audio simplicity has come far closer to becoming a reality with the introduction of music streamers from the likes of Sonos and Apple. Now just connect one of these devices to an audio system, and you’ve got an entire world of music literally at your fingertips. However, these components aren’t exactly revered for their terrific audio qualities, and many dress up the sonics by running them through an outboard DAC before connecting to a quality amplifier. But in space-challenged places like an office, kitchen, or bedroom, this can be easier said than done.
AudioControl saw this growing market segment as the perfect opportunity to bring high-performing audio to a small package in the form of the new Rialto 400. The Rialto is offered in either Sonos white or AppleTV black (technically Sierra White and Satin Black), and its svelte size makes it the perfect foundation for a compact two-channel audiophile listening system. Plus, it’s got a few other tricks under the hood.
Setup
There’s something that is just comforting when you unbox a product and it has some real heft to it. In these days of throwaway gear, the Rialto 400 feels like some real quality went into the design. For such a small, seemingly simple device, the Rialto 400 actually has a lot going on, and I’ll commend AudioControl for a very thorough, well-written user manual.
The front panel is completely devoid of buttons or controls, with just a single LED status indicator and minijack headphone connection. However the back panel is a different story completely, with a bevy of inputs, flathead screw trimpots, and dipswitches. At its most basic, you’d connect a single source to either the analog or digital input and a pair of speakers, and you’d be done in about two minutes. I connected a Sonos Connect via TosLink cable as I figured this was one of the likeliest candidates for real-world use.
There are multiple digital and analog connection options for feeding the high-end Wolfson DAC or the amplifier directly, even an unusual speaker-level input. Once your connections are made, you can individually fine-tune the analog and digital input levels, as well as overall system volume, with trimpots on the rear panel. There is also a separate adjustment for AccuBASS level, which I’ll discuss in the performance section. The Rialto 400 also provides two other options that demand a bit more discussion.
First, the amplifier is said to be stable with 4 ohm loads; it was designed to allow connection of up to two pair of 8 ohm-rated speakers (wired in parallel) to better fill a large room/area with audio. When you do so, the rated power output doubles from 100 watts to 200 watts per channel. (You can also bridge it into a single mono channel, producing a beastly 400 watts.) The Rialto 400 uses quality gold-plated, five-way binding posts that will accept heavy-gauge speaker wiring, plus an RCA output is available to connect a powered sub. It’s definitely got all the goods to be the backbone for a solid 2.1-channel system.
Second, the Rialto has a way-cool priority input system in case you want to connect more than one source. The perfect application for this would be the audio output from a television, allowing you to enjoy way better sound through exterior speakers. For example, when you turn the TV on, the Rialto would automatically switch to TV audio, requiring no interaction for the user. When the TV turns off, it returns to the previous input. Priority can be turned off or set to either the digital or analog input.
Performance
Once connections are made, and you’re satisfied with the levels on the input gains and AccuBASS, you will likely never touch the Rialto again. It’s pretty much a set-it-and-forget-it affair. Keep in mind, though, that the total lack of any front panel volume control may be an issue depending on the source you connect. The Sonos Connect I used offered full variable control via the Sonos app, as did my iPhone 5. However, when connecting to a couple of televisions, the audio output was fixed and played at the Rialto’s max level. Many TVs and cable boxes have a "variable output" option for their audio output, however, so if you experience this, check the settings menus.
I started by listening to some Rhapsody music streamed from my iPhone. Even with the questionable analog headphone output and compressed content, the Rialto produced music that sounded rich and full of life. I’ve been really digging Steve Martin and Edie Brickell’s “Love Has Come for You,” and the Rialto delivered the ethereal airiness of Brickell’s vocals and the twang and pluck of Martin’s banjo playing.
From there, I moved to my Sonos system and listened to a variety of locally stored and streamed content. Michael Hedges “Rickover’s Dream” from Aerial Boundaries is a dynamic track, and the Rialto delivered on Hedges’ superfast attack on the guitar strings while preserving the ambience and depth of the recording.
The Rialto's AccuBASS feature is designed to help bring out more depth and detail to the bottom end, restoring some richness to compressed files, and it definitely did the trick. I used a variety of content to dial in the AccuBASS for the best sound. The Crystal Method’s “High Roller” from Vegas was the perfect litmus as it let me dial in the setting to get the right amount of depth and fullness on the bottom end, but also let me know when I had gone too far by producing too much boom and bloat. AccuBASS can definitely be overused, but with smaller speakers and compressed audio, judicious use definitely improved the sound. I tested the automatic input switching between the Sonos and my iPhone, and the switchover occurs nearly instantaneously once the preferred input begins playing.
The tongue-in-cheek user’s manual—with homage to AudioControl's Pacific Northwest roots—cautions that the Rialto “will often be warm to the touch—similar to the touch of a hot cup of double shot vanilla latte in a ceramic mug from one of Seattle’s 9,368 coffee shops!” And it isn’t lying; after playing for several hours, the Rialto was indeed quite warm. It should definitely not be installed in a closed, unventilated space or have any other gear placed on or under it.
Bottom Line
The Rialto 400 definitely succeeds at what it was designed to do; it provides a terrific amplifier and DAC solution in a small package. Also, unlike so many audio products these days, the Rialto is engineered and assembled in the USA and carries a five-year warranty. For the space challenged audiophile, the Rialto 400 makes a convincing case.
Power Output: 100 watts/channel into 8 ohms, 200/ch into 4 ohms, up to 400 mono/bridged
Dimensions (W x D x H, inches): 8.5 x 2.9 x 5.4
Weight (Pounds): 4.5
Inputs: RCA stereo analog, 1/8-inch minijack analog, screw terminal speaker-level analog, coaxial digital, TosLink optical digital
Outputs: RCA subwoofer, five-way speaker binding posts
Other: 12-volt trigger