Rotel RDD-1580 USB Digital to Analogue Converter REVIEW

$1299

4.5 Stars

Mr Baker isn’t disappointed in Rotel’s latest DAC, which acquits itself ably, even to his valve-saturated hearing apparatus.

IT’S TRUE I used to think that people who committed themselves to this new-fangled computer audio thing, eschewing vinyl and even plain old CDs, deserved to be dragged outside and beaten in the kidneys with big sticks. However, now I see digital, computer-based music has a place – even in my own home. I can even sympathise if not entirely abide with those who wish to have an exclusively digital setup. Vinyl is a wonderful hobby but I concede it can be hard work.

There are many things that puzzle me in this life, and one of those is whatever happened to Rotel’s RDD-06 DAC which I reviewed a couple of years back. It was tipped as being the next big (little) thing, apparently quite highly anticipated and when I compared it to the popular Cambridge Audio DACMagic Plus, the Rotel came out way on top. And yet, it has all but disappeared off the radar, certainly barely getting a mention on any hi-fi forum, let alone getting any widespread reviews (some publications even failing to realise its existence at all). My uneducated and rather assumptive guess is that it was intended mostly for the local Japanese market and managed to trickle out into other markets without much ado, but who knows? Not that it really matters now, for happily the popular Japanese manufacturer has come up with the RDD-1580, a full sized, fully featured USB based Digital to Analogue Converter available to one and all.

Build & Features

Unlike the diminutive RDD-06, the RDD-1580 is a full-sized component but keeps to a similar visual theme as the previous model with its brushed metal housing and fascia (available in black or silver), elegant rounded edges and push-button controls. Everything is more spread out however as there is more room to utilise. You can select between two coaxial inputs, two optical and one PC USB input as well as USB/iPod/Bluetooth, the input (MP3, WAV, WMA) for which is located on the front panel next to the power standby button. A Bluetooth dongle is conveniently supplied and you can also use a USB flash drive to play files up to 24/44.1 KHz. The RDD-1580 also charges your Apple iPod while it’s in use. My Android phone wouldn’t plug into it as Rotel have designed it specifically for Apple products.

The six available sample rates are also indicated by individual LEDs along the front panel – from 44.1 KHz through to 192 KHz, about which I’ll get to shortly. A full sized remote is included and while it works great for selecting inputs and even going forward and back through tracks on an album when using the PC USB input, I found I didn’t really use it much, simply because I already use my Android phone for controlling all my digital media. Still, it’s nice to have.

Also different from the RDD-06 – and most likely down to the older model’s size restraints – the RDD-1580 sports balanced as well as standard RCA outputs and, having its own toroidal transformer (made by Rotel themselves), a detachable IEC power cable – as opposed to a wall-wart type plug.

The RDD-1580 uses not the usual one but two Wolfson WM8740 digital-to-analogue converters in a complementary configuration to help with eliminating those nasty audio foes noise and distortion. The coaxial, optical (SPDIF LPCM) and PC USB (WAV, FLAC, PCM, depending on the PC) inputs can all accept files from standard CD quality 16/44.1 right up to high definition 24/192 KHz, although for PC users there is a disc supplied so you can install the necessary driver to process the higher resolution stuff (MAC users are off the hook in this case), and you do need to set the DAC to USB Audio Class 2.0 mode (it comes factory set to Audio Class 1.0) once the driver is installed. This is easily done and as it is explained in the manual, I won’t bother going into it here. One caveat, perhaps, is that the RDD-1580 does not cater for the newish DSD (Direct Stream Digital) signals, but given the comparative enormity of these files when compared to FLAC, I can’t see many people will be racing to convert just yet, so the Rotel is probably fairly safe in that regard.

I’m happy to see Rotel are still not falling for the inclusion of all those annoying user-selectable digital filter options like certain other brands – it’s all pure source direct here. There is also no headphone jack, in case you’re wondering.

Build-wise the RDD-1580 is a beauty; perhaps a little plain looking in black though I imagine the silver will look a little flashier. It measures 431mm wide by 316mm deep and is a bit of a shorty at 55mm high, so you shouldn’t have too much trouble slotting it into place somewhere. Incidentally, around the power/standby button is a rather bright blue LED (which stays on, even in standby) and Rotel have thoughtfully provided – for those who are offended by bright blue LEDs – a special little light-blocking ring that fits snugly around the button, thus preventing your room being lit up at night like a mono-coloured Christmas tree.

Listening

For amplification I used Line Magnetic’s magnificent LM-518IA SET amplifier as well as Unison Research and Sugden amplifiers. Speakers were from Reference 3A and Q Acoustics (their Concept 40 floorstanders, review coming) while source components included my PC laptop loaded with high and standard resolution FLAC and WAV files, CD and DVD player transports and a Logitech Squeezebox Classic as a wireless streamer. I also used my Android phone to stream music – courtesy of Jango – using the Rotel Bluetooth function. Unfortunately, I no longer own an RDD-06 for comparisons but I do have an MHDT Labs Stockholm NOS tube DAC which proved interesting to compare.

When I reviewed the RDD-06 I remember being immediately impressed by its strikingly silent background from which lovely, richly detailed music was allowed to emerge unhindered. The same was true of the 1580: music had a perfectly quiet stage upon which to perform. It sounds strange referring to silence as a good thing when discussing audio but in times – as with the Rotel – where it is distinctly noticeable, music has a greater sense of immediacy, depth and detail definition; sound floats and seems holographic rather than being flat or thin. Instruments sound cleaner with more apparent texture and nuance and the overall experience can be more engaging.

While sounding, naturally, very much like a digital player, the RDD-1580 is relatively free of the harsh grain, that often overbearing aural crap that even a similarly priced CD player can have; that glare that tends to cause blood to spurt from one’s ears and guttural Wookie noises to blast out through one’s tightly clenched teeth. Rather, it delivers a sound that is very clean, wide open and dynamic as well as fast, rhythmic and punchy without any of that yucky stuff and without really trying overtly to sound like vinyl. My Stockholm DAC, for instance, with its vacuum tube buffer stage and twin Burr-Brown chips which kind of soften the edges and give a hint of analogue-like warmth, is no less rhythmic or exciting but the Rotel has an extra sparkle and polish; a DAC for those who have no – nor have ever had – any interest in those big black discs, perhaps.

Luke Doucet’s album Outlaws (Live And Unreleased) is immediate, fast and raw with closely mic-ed instruments, and I have always found it to be a great recording for testing equipment. This sounded great with the RDD-06 and it was outstanding again with the RDD-1580. On the sublime ‘Another Woman’, Doucet’s guitar sounded spectacular, the Rotel baring all the little tone and pitch changes as he wrestled and ripped notes out of it and his vocal, and was able to soar and dive without straining the speakers. Most importantly, the pace of the band as a whole was fast and exciting – the leading edges and thump of the bass notes gave added richness and the drums were particularly impressive, sounding full scale and life-like – and there was just that urgency and feeling of near-chaos one can only experience at a live gig. Not that this was like being there, as such – and I have heard the track sound better dynamically and sharper in textural detail – but this was still a convincing rendition.

A recent Howe Gelb album, Dust Bowl, was next on the agenda. This is a very nice recording despite sounding a bit like a practice session throughout, but the rugged, unpolished playing gives an appealingly live and impromptu feeling. Gelb’s dusty, weathered voice came through superbly clear and forward, keeping the listener transfixed with his every-day, rural and often amusing tales of life and love. With its gentle banjo accompaniment, the song ‘John Deere’ is an amusing ode to that quintessential green tractor (“Made to make the day easier”) – or rather, that is, of coveting and drunkenly stealing his neighbour’s brand new JD tractor (“Spent the night with a case of beer/ And I woke up this morning with my neighbour’s John Deere”). The plucking and strumming of the banjo was deliciously conveyed with lovingly rendered texture and tone. The gentle, whimsical rhythm of Gelb’s playing perfectly matched the nature and lyrics of the song. The Rotel easily relayed the essence of the performance and the recording space – I don’t know where it was recorded but it’s easy to imagine it could’ve been his kitchen or a small grotty bar in the middle of nowhere – in a nicely lit up (though not bright) and textured soundscape.

All those qualities audiophiles and music-lovers alike come to expect from good quality audio equipment are more-or-less present and accounted for with Rotel’s new DAC: fairly sprightly, detailed and not too bright treble, a well-balanced, uncoloured midrange with good timbral accuracy and a solid, textured bass performance. The soundstage is big, wide and open with great imaging and instrument colour and detail. Some might like a sharper, livelier treble and what they’d describe as tighter bass, but on the whole the RDD-1580 performs very well indeed.

Another album ably demonstrating the good points is Happy Happer by Japanese four-piece stoner-dub band Audio Active. Full of samples and blips and noises, but with actual drums, bass, guitars and other instruments, the tracks on this infectiously fun and dope-hazy recording can give speakers and source a good workout through the frequencies. The highlight for me is ‘Mammoth Galactica’ with its marching style drum beat, ebullient horns and powerful plodding bass line. The sound was room-filling, by which I mean the solid bass line was firmly rumbling away in the centre just behind the speakers – with great start/stop action – while the rest of the sound seemed to come out into the room in great conjoining arcs from the speakers. Detail retrieval was satisfying as was the clear and silent background and lit-up sound; there was no brightness or fatigue, just a lively and dynamic presentation. Just as one would expect, the music floated in the air with holographic sharpness and confident bass, and images superbly laid out across and within the soundstage.

I found the Rotel had decidedly more gain and boldness of delivery than my Stockholm, and while being quite similar in terms of detail and tonal character, the Stockholm does indeed sound smoother and more analogue if perhaps less dynamic and more laid back than the Rotel. The Rotel, like a good DAC should, has great rhythm, timing and alacrity, making a ramble, meander or epic journey through one’s music collection an absolute pleasure.

The Bluetooth function works very well with above average sound quality – if a little flat and thin – depending of course on what is being played. When I used Jango Radio from my Android phone I found I could skip through tracks using the Rotel remote, which was definitely easier than having to unlock my phone every time. I was perhaps unfairly dismissive of the Bluetooth function when I reviewed the RDD-06, but it is definitely something I have grown to appreciate and it’s great for background music when. Overall operation was at times a little glitchy (although not intolerably so) with the occasional drop out but I got the feeling this was more to do with my not-very-smartphone and, more probably, my slow-even-though-I-pay-for-high-speed internet connection.

I have read at least one complaint that the PC USB input is only average in terms of sound quality, but I don’t entirely concur with that conclusion. When I used the Luke Doucet album to compare the USB with the digital inputs, I did find that (and this is listening ridiculously hard and unscientifically) when listening through the coaxial input, I got a sense that the sound was a little bit more engaging and spacious with slightly better edges to details; like the hitting together of drumsticks and buzzing guitar amps being slightly more prominent. The USB input is still, in my opinion, as good as most but if it really did bug you (and you’d really have to be a picky so-and-so, surely) a USB to SPDIF converter is a possible way to go, as there are some good options out there. However, I expect that most people won’t be bothered.

Conclusion

Arguably all DACs – even when using different off-the-shelf DAC chips and within a certain price point – should potentially sound the same, if not similar, with any differences often being subtle at the most. But it’s really all in the implementation, and a not properly thought-out circuit can result in an inferior sounding piece of equipment. Likewise, a lack of – or conversely an excess of – features can be utterly infuriating (all of which is why it is still worth reviewing these devices). The quality of the circuitry (for instance, analogue filters, output stage and even the power supply) can make a big difference, and with such attention to detail Rotel have managed to produce a solid performing and clean sounding DAC for a pretty reasonable price, which will do very well against its peers. With that clean delivery and quiet noise-floor, the RDD-1580 gives a more-than-subtle performance, with great dynamics, good detail and an agreeable tonal palette. It may not have the charm, character or “bespoke-ness” of say, an MHDT, Line Magnetic or Acoustic Plan, but it’s a bona fide workhorse and, at least on a basic level, does what any good DAC should and more.

Thirteen hundred bucks is not too much to part with for a quality digital source, and that’s only four or five more Lord Rutherford’s than the original RDD-06. Of course there is also a lot of competition at this price point – the industry has progressed in such a short space of time that you can get some pretty stunning sounding (and featured) DACs for a lot less than you may have had to spend a few years ago. If the Rotel RDD-1580 isn’t the best sounding performer in this point of the market then it’s definitely up there with the best.

It gets a hearty recommendation from me. ANDREW BAKER

 www.internationaldynamics.co.nz/