John
Wadia’s 151PowerDAC Mini is a sealed compound: DAC, pre-amp and power-amp rolled into one box, all fused together in one clever digital circuit. There are four ways in (ALL digital: USB, optical and two coaxial) and one way out (loudspeakers). There’s no line- or pre-out. That’d cannibalise the market for Wadia’s 121 digital-pre. Amplification is all digital but this ain’t no standard Class D-esque implementation. This ain’t no B&O ICEowered device. All incoming data is up-sampled (here to 24/384) using Wadia’s home-cooked DigiMaster recipe. The PCM stream is converted to PWM which in turn is digitally amplified to drive the loudspeaker output stage.
“The only analog signal path in the digital amplifier is the output reconstruction filter. The main purpose of the output filter is to attenuate the high-frequency switching component of the power stage while preserving the integrity of all signals in the audio band.”, says Wadia’s John Schaffer.
Introduced in 2010 – an aeon in current digital audio terms – I see the 151PowerDAC Mini as the smaller, cheaper, feistier forerunner of NAD’s Direct Digital C390DD.
The Wadia iTransport-friendly remote control is reassuringly heavy and reflects the built all-round quality deployed on the this unit’s realisation. The pointed, rubber-compound feet ensure that the aluminium chassis (20cm x 20cm x 6cm, 2.72 kg) appears to float on the shelf.
Setup is absurdly simple: plug into mains, plug in a digital source (I started with USB), flip the rear power switch and let the music rip. It’s so easy even my Grandma could do it. This DAC-amplifier requires a significant run-in period. Don’t draw conclusions too early — things become smoother and more dynamic after eight or so weeks of regular use.
Let’s get a minor niggle out of the way early on so we can concentrate on the good stuff. USB only does 44, 48 and 96. No 88.2 says Audirvana+. Enter the Wyred4Sound uLINK which can pipe any sample rate up to 192 over S/PDIF. This USB convertor diversion bests the Wadia’s stock USB sound for liquidity and tonal richness by a small margin. Up-sampling to 176.4 via Audirvana+ is this reviewer’s current playback preference.
Listening sessions kicked off with 47Labs Lens loudspeakers. Single-driver are normally the preserve of SET fanciers. The 47Labs are deceptively demanding little buggers: 85db efficiency keeps sub-10 wpc amplifiers at arms length. They like a bit of grunt. With the Wadia151 they get exactly that. John Tejada’s Fabric mix is present as fast and punchy with an abundance of snappy dynamics. Transparency – seeing INTO the music – is readily apparent from the get go. Anyone who enjoys deep detail extraction will find much to like here.
The subtleties of Nick Cave and Mick Harvey’s songwriting skills are presented with flair and dexterity. This 24-bit version of the 2012 remaster of No More Shall We Part sounds exquisite. Warren Ellis’ heavily mournful violin turns are a standout – the textural reveal of the Wadia doesn’t overly romance the performance but (again) the immersive Wadia brings home emotional gravitas by underscoring the delicacy of Cave’s piano caress and cleaving space around his voice.
So far so illuminated, airy, punchy. Those three words nail the essence of this PowerDAC; but the Japanese mini-monitors can only give so much in return. The 151’s super-tight grip on bass means a presentation that’s sometimes short on heft but always long on finesse; this Wadia/47Labs pairing is a treat for the tenderness of “Love Letter” but insufficiently drama deal when the over-zealous preacher man of “Fifteen Feet Of Pure White Snow” comes a-riding. With vocal, piano, guitar and strings, this amp-speaker duo is superb, best suited to close quarters listening in small rooms and on desktops. That midrange is all Cave and Ellis. The latter’s heavy violin work dominates proceedings. That’s not to say the rhythm section doesn’t get a look in, just that its presence is dialled back in favour of textural and timbral information.
“The world is turning, I hope it don’t turn away”. The title track from Neil Young’s On The Beach kills with a thousand cuts. The spark that ignites Young’s guitar illuminates the song from from the inside out. This isn’t atypical of an amplifier that starts from the blackest of backgrounds. The Wadia is deep-space silent. A tambourine rattle buried deep in the left channel of “Ambulance Blues” appears mid way through On The Beach’s closer. Wadia strike frequently with those never-noticed-that-before neurons. Who doesn’t love that? Reminiscent of the Metrum Octave DAC, the effervescence of sparkling mineral water tantalises without ever feeling artificial. Detail that’s far from MSG enhanced — pure Perrier!
Moving toward more price-appropriate loudspeaker partners, the Usher S-520’s fickle load overstretched the little Wadia with some material. These are speakers that require grunt before refinement. This Power DAC works with those priorities inverted. An easier load was required. PSB Alpha’s B1 were just a jump to the left. 91db ensured a far more agreeable partnership. Again my listening notes read of cleanliness and transparency, particularly form the waist up.
The Wadia151PowerDAC was then compared to the latest iteration in the Nova series from Peachtree Audio. Having made the shift from Class A/B to Class D, the Nova125 offers a mightily respectable 220 wpc into 4 ohms as well as built-in DAC (an ESS Sabre 9023 implementation), switchable tube buffer and an excellent headphone output. When Peachtree-paired the mini-Maggies displayed greater tonal mass – in line with my experiences of bringing more watts to the Magnepan table – but the presentation was more recessed and polite than the Wadia. I’ve been informed that the MMG are perhaps the most laid back of all models in the Magnepan range. Hence, the dynamic sparkle of the 151 is a better match. Both amplifiers show a firm hand with low frequencies but the little fella served greater illumination, more spatial information and a soundstage depth that starts closer to the listening position. The Wadia brings the music to you. With the Nova125, you go to it. I’d wager the latter would be a superior choice with brighter loudspeakers that need bringing into line with more go-juice. A brief run with Usher’s super-budget champs – the S-520 – confirmed this. This is loudspeaker territory into which the Wadia doesn’t work as effectively as the more powerful rival. You win some, you lose some.
Currently midway through a three-way amplifier review for Magnepan’s MMG, a slew of reader emails ensued. Some readers have asked about Class D offerings, one or two about direct digital “PowerDACs” [like this very Wadia]. I hadn’t even considered it an option. I’d fallen hook, line and sinker for the desktop audio connotations of the 151’s form factor. Surely, this was amplifier for tighter corners and standmounts. The specifications sheet didn’t allude to MMG romance…
….but hallelujah, what a result! All of the 151-er’s aforementioned sonic traits mainline effortlessly into six hundred dollar panels. Here’s how the pen went down on an afternoon’s listening session:
Lambchop – Is A Woman. Purity and image specificity rain down. Guitar texture that sparkles without hardness. Subtlety and nuance make for a greater emotional connection. Voices From The Lake – Voices From The Lake. Air! Clicks and hisses more room to breathe and dart. Kings Of Convenience – Riot On An Empty Street. Veil-lifting on guitar strum and fretwork. Spatial information. Illusion or not: soundstage depth. “Brando Mumble, Mingus Eyes”. Richard Thompson’s Mirror Blue. Connotes the essence of NAD’s bigger, badder C390 DD. Clean, smooth and bags of depth. Here was a separation stunner that’s not quite as tonally dense as the beefed up Peachtree. However, there was emphatically more sparkle than the Nova125. No mess, no fuss.
Price informs the majority of critical context. My listening experiences with the Wadia 151PowerDAC all roll up into one tidy phrase: truly exceptional value for money. And that’s at the RRP of US$1299. Some online stores have been seen discounting it to $799 – here we move toward a definitive slice of must have hifi. It’s almost everything that great budget hecklers holler for: simple setup, unobtrusive form-factor – making it easy to sneak into the house – and utterly transparent and engaging in its reproduction of music. That it bucks no-go expectations with tougher loads like Magnepan’s MMG means we have a DAR-KO award winner on our hands.
Associated Equipment:
- iFi iUSBPower
- WiredWorld Starlight USB cable
- Resonessence Concero
- Wyred4Sound uLINK
- Zu Audio digital interconnect
- Peachtree Nova125
- Magnepan MMG
- Usher S-520
- PSB Alpha B1
- 47Labs loudspeaker cable
- Zu Audio Event loudspeaker cable
Audition Music:
- Lambchop – Is A Woman (2002)
- Voices From The Lake – Voices From The Lake (2012)
- Kings Of Convenience – Riot On An Empty Street (2004)
- Neil Young – On The Beach (1974)
- Richard Thompson – Mirror Blue (1994)
Further Information:
