Let’s face it: when it comes to hifi purchases, aesthetics matter. At the end of the day, if you’re spending money on something that’s about to become a central part of your life when it comes to enjoying perhaps the most emotive of art-forms - music - your emotions are bound to come into play when it comes to choosing, and then living with the gear that’s placed squarely in front of your listening position. And when said gear is usually some kind of large, rectangular box that’s likely to be a highly visible part of the living room in your house, it’s something that you (and the other people you live with!) are going to need to need to be more than just “ok” with from a design perspective.
When 95% of most hifi gear is usually some kind of black or silver “box”, most hifi enthusiasts end up choosing some kind of minimalist amplifier that’s there to a) do its job, and b) blend into a modern furniture setup and be as unobtrusive as possible. And that’s totally fine if that floats your boat - no judgements here. Now, I don’t fall neatly into the minimalist/modernist camp when it comes to design, being a sucker for mid-Century furniture and design, so it’s perhaps no surprise that I also happen to love vintage hifi - you know, stuff with wooden veneer panels, VU meters, tone controls (gasp!) and other various large clunky knobs and dials.
Music, for me, is all about the total listening experience. I love to enjoy the ceremony and visual theatre that comes with setting up my listening area, having my records on display, and yes - having an interesting-looking integrated amplifier sitting at the heart of it all. Where possible, I try not to have a TV plonked-down in-between my speakers when I’m enjoying an album, and so your vintage receiver or integrated amplifier becomes the focal point of your system, in a sense. It’s a bit like when you go to watch an orchestra play in a concert hall, and for 90% of the time you can’t help but watch the conductor doing what they do best from the podium. If the “conductor” of your home orchestra is a sterile black box with only a standby LED light switched on to give you any indication that it’s doing its thing, then that’s just a little…boring, right?
A new ROSE varietal
South Korea’s HiFi ROSE has been one of the most disruptive players on the digital audio front in recent times, being known for creating ultra-modern digital streaming devices such as their flagship HiFi ROSE RS150B High Performance Network Streamer, which, with its enormous high-definition touch-screen display and plethora of digital and connectivity talents, is the absolute epitome of ultra-modern design.
So when HiFi ROSE released their first all-analogue device in the form of the brand-new $10499 HiFi ROSE RA180 Integrated Amplifier, “unexpected” would be an understatement when it comes to the design they unveiled - this feature-laden beast of a 16.7 kilogram amplifier is very much the analogue yin to the digital yang of the RS150B, and sports what is hands-down the most attention-grabbing and decidedly retro-looking appearances of any piece of hifi gear currently on the market.
Beauty is most certainly in the eye of the beholder, but the RA180’s immense aluminium chassis covered in a bevy of manual controls, knobs and dials, bouncing lit-up VU meters, and the pièce de résistance - the stunning volume control that consists of series of visible cogs and gears - all combine to create an absolute work of industrial art, in my books. Sitting on three round feet, the all-metal RA180 feels absolutely bomb-proof from a build standpoint. It might look an intricate device, but its construction and sheer weight makes the RA180 feel like quite the substantial piece of hifi kit - it is one absolute unit.
About the HiFi ROSE RA180
The RA180 a classic “integrated” amplifier in every sense, being an entirely analogue affair from input to output. There’s no built in DAC or streamer on board the RA180, so you’ll need to BYO source device to the party. However, with three standard analogue RCA inputs, a phono input that can accept both Moving Magnet and Moving Coil cartridges, plus a pair of balanced XLR inputs, you’ll be able to hook up the RA180 with whatever digital or analogue source you desire. The RA180 also has a single subwoofer output connection should you wish to add a little more low-end into your speaker set-up, but absent is any kind of pre-amplifier output - not that you’ll be needing to use the RA180 as a pre-amplifier only, because it is one absolute beast of an amplifier in when it comes to grunt.
At the heart of the RA180 HiFi ROSE has used Gallium Nitride (or “GaN”) semiconductor-based technology to create what they have unusually labelled a “Class-AD” design which they explain combines the higher output and efficiency of a Class D amplifier with the linearity and smooth sound of a Class-AB based amplifier. While it is still technically a “digital” amplifier which provides a perfect linear output at 0% distortion and 100% efficiency, the use of GaN over a traditional Silicon FET works to provide a more natural sound by reducing the speed of the switching action to nearly zero, all the while maintaining the lower distortion benefits of a Class-D type amplifier.
Now I’m certainly no electrical engineer so I can’t comment further on the finer workings of how this curiously-labelled topology actually works, but it does mean that the RA180 can pack a pretty solid punch for an integrated amplifier - up to 400 watts per channel - all the while remaining fairly cool. It does get a little warm during spirited operation, but nowhere near as toasty as equivalent Class-A or AB amplifiers with this much power under the hood.
Multiple amps, multiple speaker applications
The RA180 boasts four independent mono amplifiers inside its chassis - two for each left and right channel - each capable of outputting 200 Watts into each channel at either 4 or 8 ohms. Like many classic integrated amplifiers the RA180 has facilities for two separate sets of speakers which can be selected via an appropriately large and tactile switch on the front panel. But further to this, the RA180 has no fewer than eight sets of large, solid binding posts per set of speakers for a total of sixteen altogether. This allows you to use the RA180 in a few different speaker configurations that will appeal to the “fiddlers” and “tweakers” among you who are looking to get a little more technical when it comes to getting the best out of your speakers.
You could simply connect a pair of traditional passive speakers via the inner two sets of +/- binding posts on either the “A” or “B” speaker outputs and easily call it a day there and enjoy 200 Watts of speaker-driving power. On the other hand, if you have a pair of bi-wired speakers you can independently connect each set of speaker binding posts to the RA180, which has two amp modules that are specially-designed for dealing with higher-frequencies - the latter being capable of faithfully reproducing sound all the way up to 100kHz, several orders of magnitude higher than what is audible by the human ear. By connecting your tweeters to the “H/F” binding posts and your full-range woofers to the standard “speaker out” posts, you can bypass your speakers’ internal crossover - and that’s where thing get a little more interesting. The RA180 has a “H/F CROSSOVER” module that can be switched either on or off, and means that you manually select the crossover point between 0.6 and 6 kHZ, and also control the level of H/F gain to tweak the output level between high and low frequencies into each transducer to suit your liking. I didn’t actually have a pair of bi-wired speakers on-hand during my review time with the RA180, but I can see this being enormously handy for more experienced hifi aficionados.
The other way to use the RA180 is in “BTL”, or Bridge Tied Load mode. By flicking a small switch on the rear of the unit into the appropriate position and connecting your full-range speaker into the correctly-labelled binding posts, you can summon an otherworldy 400 Watts per channel to wake even the most difficult-to-drive speakers into life. I tested out BTL mode with the not terribly-demanding Dynaudio Evoke 20 Bookshelf Speakers (6-ohm/86dB sensitivity), and while there was a tiny amount of audible noise-floor that was practically non-existent in “normal” mode, there was a marked leap in snap, dynamics and an overall more authoritative performance from these excellent Danish bookshelf speakers.
Lastly, the RA180 can be set into “BYPASS POWER AMP” mode which allows it to run as a pure power amplifier, bypassing the pre-amplifier and volume control stage. Because this could unleash 200 Watts of power into your speakers in an instant if accidentally engaged, HiFi Rose has gone to great lengths to ensure that this doesn’t happen! This mode is only available using the “LINE 3” input on the rear of the RA180, and actually needs to be unlocked using the companion “Rose Amp” app that HiFi Rose has developed for the RA180 (more on this later). Once unlocked, flicking the large level on the front will then engage this mode, leaving gain control to be managed by an upstream preamplifier or DAC.
HiFi ROSE RA180 user controls and experience
As you can probably tell from a single glance at the front panel of the RA180, it’s very much intended to be a “hands-on” kinda amplifier. And why wouldn’t you want to take the time to get up close and personal when you have such a classic old-school tactile experience like this one? The front fascia of the RA180 wouldn’t look out of place as the control panel in a time machine in a mid 20th-Century science fiction film - it has a real “steampunk” vibe to it. But, when you get up close you can really tell just how much care and attention has gone into both the design and manufacturing of the RA180. The dials twist smoothly, the switches flick with a solid “click”, and the tolerances of the all metal front interface are practically flawless - it really is quite the work of hifi art.
We’d better take a quick tour of the RA180 left to right so I can explain what’s going on here, as there’s quite a bit to take in. On the left-hand side of the RA180 we have the input selector switch that allows you to choose between the three line-in inputs, the balanced input, and the phono input. The dial is actually motorised, and if you select an input using the app or supplied remote, it’ll whirl and beep while it moves through each input option. It’s super cool when you first realise how it works, and it never gets old to use.
To the right of the input selection is the RA180’s “preamplifier” stage, which consists of bass and treble tone controls (offering +/- , plus a balance slider. Many audiophile consider tone controls to be quite heretic, but I’m totally fine with using them for general adjustments by “feel” to suit individual speaker and room idiosyncrasies. If you’d rather keep things “flat” or manage eq at a digital signal level, then you can switch off the tone controls altogether. Below the tone controls we have the “H/F CROSSOVER” controls that I mentioned earlier, which come into play should you wish to tinker with the crossover levels in a bi-wired speaker setup. Don’t want to use this section of the RA180? Again, you can simply switch this off.
The RA180 is equipped not only with an MM/MC capable phono stage, but also adds a degree more depth for the more hardcore vinyl enthusiast to fine-tune their sound depending on both the record being played, as well as their cartridge of choice. The phono stage can be switched on and off depending on whether you’re using it, and you can also adjust both the “turnover” and “roll-off” of the signal being sent into the amplifier to match the recommended equalisation curve of the record you’re listening to. Essentially, these control the amount of gain at 100Hz and amount of treble roll-off at 10Hz. When I first played a record via the RA180’s internal phono stage (without properly reading the manual first…mea culpa) I thought it sounded weird. After some tweaking and testing with each knob, I found that I most preferred having maximum mid-bass lift and a “flat” roll-off at 10kHz.
Next, we have (arguably) the second coolest-looking part of the RA180 - the dual VU meters. These two back lit meters house physical needles which dance upwards and downwards depending on the input level being received by the left and right channels, and add a nice element of subtle visual flair while you’re sitting back and listening to music via the RA180. You can choose to either dim or completely switch off the backlight behind the meters and the volume dial if it’s getting a little too conspicuous in a dark room, but you can bet that I didn’t touch that dial once save to check that it actually worked as intended.
The RA180’s volume control is easily the most elaborate and interesting-looking one I’ve seen implemented on a piece of hifi. HiFi Rose has used an an intricate series of interconnected cogs housed behind a transparent perspex screen that are driven by the large, chrome-finished volume knob that is skeletonised so that you can see what’s happening behind it. There’s a little bit of “play” in the volume control due to the teeth in each cog needing a little time to engage with one another, but it allows for reasonably precise adjustments as shown by the red indicator in the top part of the volume “window”. Sure, a stepped attenuator or even a regular potentiometer would have made for a smoother, more precise way to control the RA180’s volume, but when it looks this cool you’re certainly glad that HiFi Rose went with this option - it’s amazingly enjoyable to use. And, did I mention that it’s motorised? When you change the volume via the RA180’s remote or via the Rose Amp app, the whole knob and gear system rotates accordingly. You can even change the speed at which the motor works via the app to allow for quicker or more precise adjustments.
Rounding out the RA180’s physical controls, we have a lever to control the power amp bypass mode; the speaker selector switch; a dimmer switch for the display light; an “ATTENUATOR” switch which immediately drops the volume level substantially (should you need to in a hurry); plus a “SUBSONIC” switch. This last function cuts bass levels below 50Hz which can be useful when playing records with low-level noise artefacts which can cause shaking or rumbling in your speakers.
If you want to dig a little deeper into what precisely is going on with the engagement of each control option on the RA180, HiFi Rose has helpfully provided a very comprehensive user manual, complete with EQ graphs to explain what each filter and control is doing at each exact frequency. It’s a nice addition and ought to appeal to the analogue nerds among you.
A simple aluminium remote is provided with the RA180 which controls the most important basic functions on the amp: powering it on and off, muting, selecting between the five inputs, and controlling the volume. The remote is a little more “minimalist” than the RA180 itself, but it’s entirely functional and works well. One thing that prospective owners should note is that there’s no infrared remote receiver on the RA180 itself - a small “nubbin” of a remote receiver is supplied with the amp that is plugged in the rear of the device, just below the trigger input. This means that you’ll need to house it somewhere near the RA180 in order to use the remote, but it’s pretty unobtrusive.
The RA180 might look like a classic vintage receiver from the outside, but HiFi ROSE has somehow managed to squeeze wifi connectivity inside the unit to allow for connection to the Rose Amp companion app. Until I scoured the manual I had no idea that the RA180 actually had wifi/app connectivity, but having spent some time experiencing HiFi ROSE’s digital wizardry with the RS150, I shouldn’t be altogether surprised.
The app houses the exact same functionality as the RA180’s physical remote, and also provides some further device management options such as managing the volume motor speed, maximum amplifier gain (up to 32dB), standby and auto shutdown settings, plus the lock/unlock functionality for the power amp bypass mode. The app even shows what each of the amp modules and dials are set to on a visual display, although aside from the input and volume knobs, the remainder aren’t motorised and can’t be controlled via the app.
All in all, there’s quite a lot to take in with the RA180. It can certainly be a “plug and play” integrated amp if you just want to plug in a source plus speakers and kick back and enjoy you music (plus looking at the RA180!), but there’s so much that can also be done from a fine tuning perspective if you want to tweak your speakers’ sound, the way you control your vinyl playback, or the way you use each combination of the four amplifier modules in concert to drive your speakers. While it evokes all the nostalgia of a classic vintage receiver from a looks perspective, about the only thing absent from the RA180 to complete this picture is a headphone jack! You’re certainly not picking up a 400 Watt-per-channel integrated amplifier to do headphone listening with, but I do like the inclusion of a headphone output on an integrated amp - even if it is just a simple resistor implementation from the main power amplifier stage.
Listening to the HiFi ROSE RA180
During my review time with the RA180 I had the perfect digital source companion on-hand to partner with it - its digital stablemate, the RS150B DAC and streamer. Sitting next to one another they look like chalk and cheese, but displacing roughly as much shelf space as one another and sharing the same rectangular dimensions on their front panel, they really do offset one another in terms of both looks and capabilities. With the RS150B taking care of digital audio streamed from Tidal, Qobuz and my own FLAC library, I also hooked up the Thorens TD 102 A Automatic Turntable into the RA180’s phono stage input to get an idea of how it handled vinyl playback, and in turn connected the RA180 into a pair of Dynaudio Evoke 20 which were set up on stands in my home living room.
Starting things off with a Qobuz stream of The Decemberists The Tain EP courtesy of the RS150B, the impression the RA180 gave me in terms of its “voicing” was that it’s a lively-sounding amp with all the positive benefits of Class-D: quickness, clarity and immediacy. While it may look like a vintage receiver, it doesn’t have the same warm laid-backness that you might expect from an amp with ye olde analogue charm. However, it did have a pretty prodigious grip of the Evoke 20’s generous low end, which would feel more appropriate on a pair of tower speakers - there was certainly no need for a sub to be integrated in my medium-sized listening room. After checking that the bass dial wasn’t accidentally nudged up slightly, I settled in to enjoy a brisk and nicely-textured listen through the many changes in tempo and volume in The Decemberists’ 5-part interpretation of the Irish folk epic. I was particularly impressed with the way the RA180 brought out the lowest double bass notes in an incredibly lifelike and authoritative way at the 8:15 mark.
I was impressed by the way that the RA180 manages to impart a sense of dynamics, especially when at lower volumes. In “standard” mode, I usually had the volume set between 10-15 out of 99 (the app tells you exactly where the volume is set) and with 200 Watts available on tap, I always felt like there was an enormous amount of headroom ready in reserve to manage large dynamic swings or to “rock out” if I dared to nudge up that brilliant volume wheel any higher - I didn’t manage to get it past “20” during my testing.
Listening to Lake Street Dive’s Hypotheticals the RA180 showed an extremely tight grip on the bass guitar notes and kick drum thumps, dispatching them quickly and convincingly without the slightest hint of flabbiness. The backup vocals at the 3:20 mark sounded like they were coming from far wider than the confines of the speakers themselves, and there was a rock-solid centre image from lead singer, Rachael Price, whose voice sounded far more natural than I’ve heard from any other Class-D amp I’ve encountered to date.
Class-D amps, from my experience tend to lack a proper sense of tonal mass, which in turn can create a bit of a smeared “sheen” across things and leave music sounding slightly unnatural. While the RA180 doesn’t have the out and out richness of a Class-A or even a Class-AB amp, it has the dynamics and pep to get your feet tapping and simply make music enjoyable. Combined with its speed and clarity, I’d say that it’s probably a better match for those of you looking for a slightly more energetic presentation, or perhaps if you want to inject a bit of needed verve into a more laid-back pair of speakers that benefit from a bit of added gusto. Switching the RA180 into “BTL” mode, which in effect makes it a 400 Watt-per-channel stereo amplifier takes things up another notch all together. The dynamic attack in Metallica’s Sad But True rose markedly, and also gave an added sense of alacrity and extension to the sheen and bite of cymbal hits in the highest octave - I’d suggest definitely keeping the RA180 in BTL mode if your speakers aren’t too sensitive.
The RA180’s phono stage is simply excellent. A spin of my 45rpm copy of Radiohead’s Hail To The Thief on the Thorens TD 102 A yielded brilliant results. The subsonic filter eliminated flutter from my speaker’s woofers, and after some play with the phono equaliser settings I found both the tone and dynamics as well as the low noise of the RA180’s inbuilt phono stage to be as convincing as any external standalone unit. The piano, hi-hat and simple revolving guitar track in my favourite track on the album, A Punchup At A Wedding sounded crisp and detailed, while Thom’s voice had all his trademark urgency and emotion on show. The droning synth bass in the next track, Myxomatosis was brutally luscious. Vinyl enthusiasts really ought to take note of the RA180’s ability to tango with all kinds of records and cartridges, and play them back with aplomb - it’s an analogue delight.
I don’t need to repeat myself in saying that the RA180 is a terrific looking piece of hifi - it’s simply peerless in that regard. As much as I think that the RA180 will suit those who audiophiles who are looking for a terrific “statement” piece to place at the heart of their setup and proudly put out on display, in terms of its features and talents it’s also an integrated amp that can easily take the place of a separate pre-amplifier, phono-stage and power amp.
In terms of analogue talents and features, HiFi ROSE has packed everything plus the kitchen sink into the RA180. It’ll provide the experienced hifi enthusiast a huge amount of flexibility to tailor their listening arrangement down the track, and will certainly keep them “busy” in that regard. And once you’ve found your perfect setup with the RA180, all that’s left is to put your feet up, put on your favourite music and smile while you look at it. It’s an amazing first amplifier from HiFi ROSE, they’ve certainly made their mark with the RA180.