• Rotel RDD-1580
Our Verdict 
There’s plenty to be impressed with this Rotel DAC, but its poor USB input holds it back
For 
Remarkably clear and precise sound
Even tonal balance
Direct and expressive vocals
Extensive feature spec
Good design and build
Against 
Rear USB input sounds poor
Treble could have more spark
Reviewed on

We haven’t seen a standalone Rotel DAC in a long while now, and this new RDD-1580 has come in with guns blazing.

This high-resolution DAC aims high with a full array of digital connections – including USB inputs and Bluetooth streaming – and a clear, balanced sound, but it’s not without its faults.

What’s interesting is how different the RDD-1580 sounds depending on which input you use.

But before we get stuck into the Rotel DAC’s musical idiosyncrasies, we must first applaud it for the extensive selection of inputs it offers.

Connections

Two coaxial inputs, two optical inputs and an asynchronous Type B USB input – all of which support high-res audio files of up to 24-bit/192kHz – are plenty enough to plug in your streamer, CD player and laptop. 

There’s another USB port on the front panel, which proves to be a versatile connection: you can play songs from a USB flash drive (but only up to 24-bit/48kHz), from any Apple smart device; or plug in the supplied Bluetooth dongle to give the RDD-1580 the gift of wireless streaming.

We should point out that you can only play Apple devices (iPhone, iPod, iPad) through the front USB port. It will also charge your device while playing. 

You get two options for analogue outputs: a pair of line-level RCA plugs and a pair of balanced XLR outputs.

Bluetooth

We like that Rotel has added in the Bluetooth option with the RDD-1580, giving it another level of versatility. The Bluetooth dongle itself is much smaller than any normal USB stick and looks unobtrusive when plugged into the DAC.

Bluetooth pairing is swiftly done, and we didn’t experience any drop-outs or hiccups when streaming Spotify tunes from an Apple iPhone 5.

Design and build

The DAC itself is a slim metal chassis, available in black and silver finishes. Its size and shape (similar to Rotel’s stereo amplifiers) places it firmly as part of a hi-fi set-up.

It’s not compact enough to sit as part of a desktop system, and the lack of a headphone output and volume controls further indicates that.

The front panel is sleek and neat, with bright blue LEDs indicating which input and sampling rate is being played. There’s an audible click as it switches from one sample rate to another.

There’s a button for each of the six inputs on the front. It’s worth remembering that you’ll have to push the ‘USB’ button when playing Bluetooth.

The supplied remote control is useful for changing inputs, but the design is rather sparse and clunky.

More after the break

Sound quality

Playing Radiohead’s 15 Step from our Naim reference streamer and into the Rotel’s coaxial input, we’re struck by how remarkably clean and straightforward the RDD-1580 sounds.

Each instrument is carefully and precisely laid out, and there’s a good sense of rhythm and crispness to the edges – it’s quite the feat considering the song’s intricate arrangement.

There’s good weight to the sound, too, and the tonal balance is even throughout the frequencies.

Nick Cave’s measured vocals sound direct and expressive on We No Who U R; you can easily hear the reverbs in the song. The treble could be a tad sweeter, but there’s plenty of depth and wallop in the low end.

Switch to Breezeblocks by Alt-J, and the Rotel can’t quite render the playful and agile rhythmic framework convincingly.

The depth of detail and the even tonal balance remain, but it’s not quite as exciting and musical as its rival – the Award-winning Audiolab M-DAC (£600).

The M-DAC is quick to respond to abrupt changes in rhythm, and has a punchier, more interesting sound – but not by much.

The Rotel is weakest through the rear USB input. The detail, weight and dynamism that we heard through the coax input all disappear.

The bassline on Trent Reznor’s On We March becomes rather flabby and lethargic, the treble is further strained and the entire presentation just sounds weak.

We played a couple more tracks through iTunes and Spotify, and the result was the same lacklustre sound.

We’re disappointed, as the USB input would’ve been most convenient (and crucial) for those wanting to use their laptop or desktop computer as the main music source. But it’s far from a deal-breaker.

There are other ways of using the RDD-1580 that better exploit its talents.

We’d advise you to use the Rotel’s optical input instead, which falls somewhere between the coaxial and USB inputs’ sound.

You’ll need an adapter to plug the optical cable into your laptop’s headphone output, but it’s a small price to pay for a far more detailed and punchier sound than you’d get through USB.

But the surprise of the lot came when we plugged our iPhone into the front panel USB port – it sounds surprisingly good. Even allowing for a drop in subtlety, Dio’s The Last In Line packs a punch.

There’s a good sense of power and energy charging through the heavy metal track, and we found ourselves tapping along to the Rotel’s newfound agility.

Bluetooth streaming delivers a similarly snappy sound; once we’d heard it, we spent the rest of the afternoon happily streaming our Spotify playlists. 

Verdict

We have mixed emotions about the Rotel RDD-1580. On one hand, we really like the clarity and balance of its sound and the amount of digital features on board is impressive.

On the other hand, the poor quality of its PC-USB input is a big letdown. And in absolute terms, the rival Audiolab M-DAC delivers a more engaging and energetic performance – for the same price. 

If the sound quality had remained consistent throughout all the inputs during our test, the Rotel RDD-1580 would have had a good shot at getting the full five-star treatment.

As it is, despite its promising start, the existence of better-sounding rivals means the Rotel falls just short of being an unequivocal winner.

MORE: See all our DAC reviews

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