Audia Flight FLS9 Integrated Amplifier Review

Posted on 6th July, 2022

Audia Flight FLS9 Integrated Amplifier Review

James Michael Hughes thinks this stylish Italian integrated amplifier presents a near-perfect face to the world…

Audia Flight

FLS9 Integrated Amplifier


Audia Flight FLS9 Integrated Amplifier Review

Italian manufacturer Audia Flight produces exotic handmade high-end hi-fi products in three ranges – the reference series Strumento, FL Three S, and FLS. The FLS9 integrated amplifier you see here embodies technology found in the Strumento line, promising exceptional performance but at a more affordable price.

If weight is any yardstick of quality, then this amplifier immediately creates an impression of substance. Tipping the scales at 25.5kg, it's a big, heavy beast, measuring 450x150x440mm (WxHxD). Massively built, it feels utterly bomb-proof. Available in silver or black, the brushed-aluminium front plate is 1.5mm thick, with a top plate 1mm thick. Such hefty construction reassures you that it's built to last, inspiring confidence in those lucky enough to afford one. It's a luxury piece of kit; make no mistake.


The FLS9 offers five analogue line inputs, comprising three unbalanced (RCA) and two balanced (XLR) sets. The basic line-only version costs £5,950, but other options are possible. For example, there's space at the back for a DAC (£1,850), an MM/MC phonostage (£1,100), or a module that adds a couple more line-ins – unbalanced RCA or balanced XLR (£500). If you add the DAC and phonostage, the price increases to £8,900.

A conventional Class AB design, it offers a claimed 150W into 8 ohms, 290W into 4 ohms, and 500W into 2 ohms – these figures suggest a very strong power supply. Indeed, a large 1,000W toroidal transformer is fitted, with a generous 120,000uF of capacitance and no fewer than eight separate feeds. Clearly, great care has been taken over this vital aspect of the amplifier's design. The manufacturer says that the power amp utilises twelve carefully selected output transistors, while the printed circuit tracks are made from thicker-than-usual copper.

The built-in DAC section employs an AKM 4497EQ chip which offers up to 32-bit, 768kHz processing, with upsampling to 192kHz and optional DSD. The USB, coaxial and balanced AES-EBU XLR inputs are galvanically isolated, and there are two optical inputs.

Audia Flight FLS9 Integrated Amplifier Review

The manufacturer's specs are super impressive, with a claimed bandwidth of 0.3Hz to 500kHz, total harmonic distortion of less than 0.05%, and a damping factor of 500. The circuits feature trans-impedance amplification with current-only feedback, as the manufacturer believes that voltage feedback harms performance. The feedback loop is closed before the output stage, while control circuits protect the output against faults. This amp draws less than 1W in standby mode and is inherently very quiet; noise (hiss or hum) is virtually absent, and a signal-to-noise ratio of -110dB is claimed.

When partnering the FLS9 with my 102dB efficient Klipsch Cornwall IVs, there was no residual hiss or hum from the speakers – even with an ear close by the drive units. The amp is mechanically quiet, too; despite the use of a large mains transformer, there was no annoying buzz. Well, almost none, as with my ear by the front panel, I could just detect a very faint transformer buzz. However, to put this into perspective, the tiny power transformer in my Auralic Altair G2 streamer makes far more noise! As the G2 was close by, I had to switch it off in order to detect the barely audible sound emanating from the FLS9.

The fitted phonostage is very quiet. Loading adjustments via fiddly DIP switches are offered but – being around the back – are tricky to access. This is just one of several operational quirks that the FLS9 suffers from. For example, when selecting different inputs or engaging certain other settings, you need to press a button and then use the volume control to scroll through the various options on the display. Quirky? Never! Just think of it as 'Italian flair' and individuality. Think Ferrari…

Audia Flight FLS9 Integrated Amplifier Review

The volume control spins freely, and movement is quite light. There's also a slight lag, which means you can easily scroll past the option you want. If Audia Flight added physical indent points, this would make operation more tactile, but using the remote's +/- buttons helps for some commands.

The OLED screen clearly displays information such as input selected, sampling rate, or volume level. But the display itself is slightly recessed. So, if the FLS9 is at waist height on a rack or shelf, and you stand in front of it and look down, the upper half of the display is obscured. As a result, I had to kneel in front of the unit – as if praying – to see what I was doing! Yet, despite a few grumbles, this unit is nice to use, and its foibles wouldn't put me off buying one. I like the way that pressing Mute fades the music up or down, rather than starting or ceasing it abruptly.

I love the volume control. You can set levels in precise 0.5dB steps from -90dB to +10dB. For me, this is an ideal arrangement – being able to set the volume in defined, repeatable 0.5dB steps is incredibly useful. Accurate level setting is hugely important while reviewing and making comparisons. Some find these 0.5dB changes in level too fine, but I cannot agree – better this than too coarse. Also, remember that the FLS9's volume control is linear over its entire range. Conventional analogue volume potentiometers employ a logarithmic track that better suits the ear's non-linear response to level.

Audia Flight FLS9 Integrated Amplifier Review

The FLS9 is quite customisable. For example, you can increase or decrease the gain of each individual input by +/- 6dB to equalise volume levels between different inputs. You can even add dither – a low-level hiss that helps mask digital artefacts that can lead to quantisation distortion. Classy!

During use, the amp's case gets pretty warm to the touch. Big fins on either side of the housing helps dissipate heat, though the entire chassis acts as a heatsink. After four or five hours, the casework can get quite hot, especially if you leave the amp running with no music playing. This suggests the FLS9 is running closer to pure Class A than many other similar Class AB integrated amps. It certainly runs warmer than the Perreaux 200iX (200W) or my regular Musical Fidelity Nu Vista 800 (330W). My review sample had been used before I got it, so it was fully run-in.


My first impressions were of a crisp, open-sounding amplifier that was clean, natural, and detailed. Its firm solidity and quiet authority were impressive. But after a few days of listening, I realised there was more. Yes, the FLS9 sounded very clean and well-mannered, with a smooth, effortless precision that made it a pleasure to listen to. Yes, it's a very fast-sounding amplifier, able to turn on a dime, but these early responses merely scratched the surface. The FLS9 has a certain something extra to offer…

Its pace, rhythm, and timing are superb. Slow and ponderous, the Audia Flight is not. Presentation is crisp, focused, and clear. Yet the ear is never assailed by a welter of sharp unrelated leading edges. Transients are fast, but not in an obvious, obtrusive way. There's no smearing. Nor do loud sounds mask quieter ones. This creates an impression of clarity and stability where voices and instruments inhabit their own space and retain all their individuality and separation. Allied to this is a firm, solid, powerful bass and clean open treble.

Audia Flight FLS9 Integrated Amplifier Review

I began with CD sources, using a Heed CD transport connected to an Auralic Altair G2 Streamer/DAC. Before getting the Audia Flight FLS9, I'd been dallying with a not dissimilar integrated amplifier from New Zealand brand Perreaux – the 200iX. Tonally, the FLS9 seemed a tad leaner and more open than the richer/warmer fuller-sounding 200iX. Playing a jazz CD – New Blues by Barrie Nathan and Friends – I was really impressed by the manner in which it kept the individual instruments sounding clear and separate.

You could easily follow what was going on in the performance - not just the dominant instrument(s) but those in the background. So while a sax soloed and the piano played quiet chords in the background, you'd notice the drums shoot out snappy, crisp little breaks. The sax sounded clear and forward yet did not dominate the other instruments. With several things playing at once, each instrument retained a proper sense of individuality. The initial attack of a piano chord registered clearly, but you could also savour the decay of the notes as they faded away.

The FLS9's timing was excellent, then. Being able to hear every detail so clearly made the music – and overall performance – seem more interesting and rewarding. Returning to the Perreaux 200iX after a few days with the FLS9, I quite liked its rich, full, sweet sound. Tonally it seemed creamier, but the 200iX wasn't nearly as good as the FLS9 when it came to delineating precisely what was being played and how. The difference could be quite marked. The FLS9 lets you hear lots of subtle, hidden detail, while the richer-sounding Perreaux was smoother and more homogenous.

On Berangere's Nightmare #2 from Dexter Gordon's The Other Side of Round Midnight on Blue Note, the FLS9 clarified the knotty time signature of this dense, intricate track. It made sense of the music. Despite much anarchic, chaotic playing, I could feel the pulse and discern the direction of travel.

Trying the Heed CD transport with the FLS9's built-in DAC, the resulting sound was slightly sharper and more tactile compared to the DAC in my Auralic Altair G2 streamer. I have the G2's anti-aliasing filter set to Smooth so that partly explains why. The FLS9 offers a choice of seven different anti-aliasing filters. The final option, Audia Flight's own filter, is claimed to provide a more organic sound and is the recommended setting. As the other AA filters only produce fairly subtle differences, I ended up sticking with AF's preferred option.

Audia Flight FLS9 Integrated Amplifier Review

Performance on vinyl using this amplifier's phono module turned out to be excellent. The circuit topology is, I understand, based on the company's FL Phono phonostage, which costs £3,750. I made comparisons with Pro-Ject's Phono Box DS3 B phonostage in full balanced mode. In fairness, this is much cheaper than the FLS9's phono module, costing half as much. Yet the DS3B is extremely good and confers balanced working (input/output), which takes its performance to a higher level than the price might indicate. Despite this, the FLS9's phonostage proved noticeably better.

For example, playing Andre Previn's 1960 LP of selections from Bernstein's West Side Story for Jazz trio, I was spellbound by the dynamic finesse and tonal subtlety revealed by the FLS9's phono section. Every tiny detail seemed to tell, allowing all kinds of delicate inflexions to be heard. The FLS9 phonostage offered impressive clarity, keeping piano, bass, and drums very well defined and enabling you to follow each instrument very easily.

In Maria, Previn takes things quite slowly. His playing is dreamily romantic and quite magical – time almost seems to stand still. Interestingly, the same track via the DS3 B sounded very good but didn't give me goosebumps. The playing no longer seemed quite so mesmerising and magical.


Without question then, Audia Flight's FLS9 is an exceptional integrated amplifier. It sounds clean and detailed on both analogue and digital sources, reproducing music with power and drive. Yet, at the same time, it's surprisingly delicate and capable of remarkable subtlety and finesse. It has amazing clarity, allowing listeners to follow several instruments playing at once without requiring brain-busting concentration. It's got fine timing and is particularly good at reproducing music with complex time signatures and anything that has pace.

Despite all this, the FLS9 does not thrust detail at you. Its musical presentation is smooth, relaxed and mellifluous. I rate it very highly. It's one of the best integrated amps I've ever heard. For all its power and drive, and despite a wealth of information and detail, the FLS9 finesses the ear. The optional MM/MC phono stage is also outstandingly good, among the best I've experienced, and is whisper-quiet. The built-in DAC is likewise excellent, delivering superlative results. And usefully, you don't have to buy these 'extras' if you don't need them.

Competition among premium integrated amps is intense. Yet while the FLS9 finds itself up against some formidable alternatives and big names, it need not fear its rivals. This is a superbly well-made, versatile box of delights that offers great sound and luxurious build quality.

Visit Audia Flight for more information


    James Michael Hughes's avatar

    James Michael Hughes

    An avid audiophile for many decades, Jimmy has been writing about hi-fi since 1980 in a host of British magazines, from What Hi-Fi to Hi-Fi Choice. Based in London, England, he’s one of the UK’s most prolific record and CD collectors – no streaming service can yet match his amazing music collection!

    Posted in:Hi-Fi Amplifiers Integrated Amplifiers Applause Awards 2022
    Tags: audia flight  elite audio 


    Want to share your opinion or get advice from other enthusiasts? Then head into the Message Forums where thousands of other enthusiasts are communicating on a daily basis.