Audia Flight FLS10 integrated amplifier

The dogma of separates has long reigned supreme among audiophiles: If you're serious about sound quality, you're supposed to need a dedicated preamp and power amp. The logic goes that separates reduce interference and offer maximum control over your sound. But there's an argument to be made that integrated amplifiers are more practical ... and potentially better-sounding.

The beauty of an integrated amp lies in its synergy. Audio engineers know exactly how the pre and power sections will interact; the two are literally designed to work together. On paper at least, that means optimized impedance matching, and signal integrity that can rival and perhaps surpass separates. How do you know whether a standalone preamp is a great match for a power amp? For most of us, it's through trial and error. It isn't unusual for restless stereo aficionados to own multiple combos over the years, in search of the ideal one. That gets costly.

Then there's the fact that an integrated amp helps declutter a room, appealing to minimalists and people whose living spaces are less than cavernous. Another plus: no need to shell out for audiophile-grade interconnects.

The why and how
The Audia Flight FLS10, an Italian integrated, came into my life because I'd been scratching my head over a pair of top-of-the-line Diptyque panel speakers that I'm planning to review for this magazine. Once I had them in my home and properly set up, the Diptyques' midrange and treble was as lush and engaging as I remembered from the Tampa and Chicago audio shows where I'd heard them. Bass, however, was another matter. The lower octaves seemed on the lackluster side. I knew that the speakers weren't at fault, because on those previous occasions they'd reproduced bass frequencies superbly. The Diptyques seemed to cry out for something grippier than the tubed monoblocks with which I'd paired them.

I considered using a tube amp for the mids and highs and a solid state one for the bass, but each Diptyque Reference has only a single set of binding posts. The next best plan: a solid state amplifier fed by a tube preamp—to wit, my recapped Krell FPB 200c reference power amp paired with the wonderful Margules SF-220 tube preamplifier that's shone in multiple pairings in my room. Just in time, however, I remembered that Krell FPB amplifiers have a peculiar limitation: The manual cautions that before you can safely use an FPB with a valve preamp, "coupling capacitors must be inserted into the signal path" by authorized service personnel. Ugh.

I didn't have another power amp/tube preamp combo on hand—at least not of the quality that would do the Diptyques justice. As I started considering solid state solutions, I received sage advice from Michael Hoatson, a prominent Diptyque dealer in Maryland (footnote 1) and an indefatigable panel-speaker evangelist. He was blunt about it: "Audia Flight is the best you will ever hear a panel."

As it happens, Diptyque's US distributor, Fidelity Imports' Steve Jain, also carries Audia Flight's products. In fact, the Italian amps had been used to drive the Diptyques at the audio expos I'd visited. That settled it. A loan was arranged, and some weeks later, a wooden crate showed up at my door containing the Audia Flight FLS10 fully balanced integrated amplifier.

The PDF manual I'd already perused advised to simply unscrew the crate's lid, but there were no screws on the top, only nails. That necessitated using a hammer and a small crowbar, after which the rug in my room was full of splinters and woodchips, and the crate looked like it had been gnawed on by bears. Scusami tanto!

My friend Matt and I took the lid off the crate and manhandled the 79lb amplifier onto the top shelf of my audio rack, 3' off the floor. I made the necessary connections (footnote 2) and hit play. Presto: taut, deep bass, complete with slam and authority. From a pair of panel speakers, no less!

Over the next couple of months, the dual-mono FLS10 demonstrated its mettle and versatility by also coaxing terrific performances from my Focal Scala Utopia EVO reference speakers. Then the same amp made a pair of Estelon X Diamond MkIIs sing in full-throated but controlled fashion (see my appraisal of the Estelon in the January issue). I hadn't intended to review the Audia Flight, but it was clearly a worthy subject despite not being a recent release (the amp was introduced in 2017). Based on my enthusiasm for the Italian charmer, Editor Jim Austin agreed to a review, so here we are.

Getting acquainted
Funny thing: I hadn't especially liked the FLS10 when judging it purely on design and ergonomics. The large stepped volume knob on the right of the half-inch–thick fascia is recessed, sticking out only 0.18"—less than the length of a match head. It's not very easy to grab and spin.

Compounding my reservations was the FLS10's remote control. It has eight identical half-sphere buttons, each the size of a small ball bearing. The simple uniformity looks attractive, but it doesn't make the device a cinch to operate by touch. Over time, I made peace with the remote and learned to appreciate its pleasant heft (but not the fact that you have to remove five noncaptive screws to replace the CR2032 coin-cell battery).

A final niggle concerns the two-line blue OLED display on the FLS10, mounted inside a swoopy 11"-wide strip that looks a bit like the visor of a space trooper. Each line can display roughly 15 dot-matrix–like characters, providing handy feedback such as volume level, input selection, and other basics. But the swoop gives the top of the casework a slight overhang, a kind of brow, so that when you're viewing the display from a standing position, the top line is obscured. In fact, so is the bottom one if you're closer than a couple of feet. This means that when you press any of the controls on the front panel, the screen is practically invisible ... unless you've placed the FLS10 at eye level. If not, you'll have to bend down or crouch to see the readout.

But honestly, after a couple of months with the amp, I had come to regard all those things as charming quirks rather than deal-breaking shortcomings (footnote 3).

From left to right, the six small sunken controls on the fascia are the amp's on/standby switch (the actual off switch is on the back); the input selector; a menu button that lets you change various parameters via the volume knob; a mute button; a phase toggle; and a "disable speakers" switch that you press when you jack a pair of headphones into the ¼" input on the right. Except for that "SPK" button, all these functions are also available on the remote control. An LED near the bottom center lets you know if the amp is in standby mode (amber) or fully on (blue).

Around back we find eight gold-plated speaker terminals instead of the usual four, to facilitate biwiring. Then there are three sets of RCA inputs, two pairs of balanced inputs, RCA and XLR outs, a REC output, a power switch, and the usual receptacle for a three-prong IEC power cable. That's on the standard-issue FLS10. The removable covers on the back are for optional expansion boards, such as a user-installable MM/MC phono stage ($1499). The FLS10 I received also arrived with a DAC module ($2499), which features five galvanically isolated digital inputs: asynchronous USB, two TosLink optical, an S/PDIF coaxial, and an AES3. I made extensive use of the latter two, by feeding them the signal from an Aurender A20 and a Grimm Audio MU1, respectively. Audia Flight uses an ESS ES9028PRO DAC chip (the same one we see in the formidable Benchmark DAC3). The DAC's dynamic range is given as 133dB, THD+noise as <0.01%, while the music streams up to 32-bit/384kHz/DSD512.

Audia Flight says on its website that "the amplifier's main power supply is made by 16 18,000µF 50V low impedance capacitors and is then composed of two super high current power supplies per channel, as well as four stabilized independent stages per each channel: two for the input stages and two for the Audia Flight current feedback stage."

A 15VA toroidal transformer is dedicated to the logic control and protection circuit, keeping it isolated from the audio section. Inside the chunky aluminum chassis we also find custom-printed circuit boards made with extra–high-grade copper, and "a 2000VA toroidal audio transformer enclosed within two ferromagnetic shields and encapsulated by epoxy resin powering the output stage." Because the Audia Flight team believes that "fuses are like resistors and can negatively impact the sound," the company instead uses "a current sensor read by a microprocessor." The amplifier's output stage performs in class-A for the vital first 8W ... and runs pretty hot as a consequence. My digital infrared thermometer measured 103°F on the middle of the top plate and 115°F at the heatsinks on the sides.

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Footnote 1: See listenroom.com.

Footnote 2: "The use of interconnect and speaker cables of the highest quality is strongly recommended," says the FLS10 manual. I mainly used cabling from AudioQuest's upper tiers: Thunderbird Zero cables for the speaker connections, a WEL Signature AES3 cable for the Grimm MU1 streamer, and AQ's Coffee coax and Vodka TosLink cables for other digital components.

Footnote 3: It reminded me of my 2008 Saab convertible, which I drive whenever the Maine weather allows. It has a button marked AC OFF; embedded in that button is an LED. When the LED is on, the air conditioning compressor is off. If you press the button, the light goes off—and that means the compressor is now on. How convoluted and unintuitive is that? But after a few months of ownership, that crackbrained control had become endearing to me. It somehow made me like the car more. And so it was with the idiosyncratic aspects of the FLS10.