Disclaimer: plusSound graciously provided the plusSound Cloud Nine for the purposes of this review. It starts at 349$ USD. You can find out all about it here.
Device Type: Solid State
Battery Type: 9V (x2)
Frequency response: 20hz – 20khz +/-0.1dB
Gain: 1x/0dB, 5x/10dB, 10x/20dB
Input impedance: 50K
Output impedance: <1 ohm
Maximum output: 200mA
Power rating: 1.28W into 32 ohm, 1W into 50 ohm, 250mW into 300 ohm, 120mW into 600 ohm
Noise floor: ~-150dB
Protection: Reverse battery
Input/Output: 3.5mm Switchcraft / 3.5mm Switchcraft
Dimensions: 2.3″ x 4.5″ x 0.95″
Weight: 3.2 oz (without batteries)
Let’s get physical
Cloud Nine is as close to a moon boot as a portable headphone can be. It starts with the unapologetically mottled finish. It continues with the finely scored battery bolts and almost-holographic labels. Then there’s the easy-sliding gain and power switches that duff rather than click into place. And, like a day spent destroying snow forts, the sallow lamp is all fun and games. Want it by your bedside? No problem. Want to know the amp is still in the day time? Ditto.
And, Cloud Nine is an appealing, if completely anachronistic shape.
I’m most into its 1970s SLR silver finish. Most into it indeed. It makes me miss my old Pentax K1000.
Ergonomically Cloud Nine works: there’s enough space between ins and outs to plug in most modern ins and outs. But, if you’ve got fat interconnects and headphone plugs, Cloud Nine will cramp up. Here’s my opinion: the gain switch should be situated between the ins and outs for a more comfy faceplate.
And the aesthetically pleasing bolts about which plusSound say:
Amplifier features back panel with thumbscrews for easy battery switching.
There ain’t nothing easy about removing, or inserting the battery again. Sure, the batteries spring out when finally you wrench those little buggers away. But trust me, you’ll need a wrench. Or a grade six. They’re positively Lilliputian. And the rear cap really scrunches down on the dual 9V power supply, making it difficult to both handle the batteries, and get the rear cap on with only two hands. And for your trouble? The rear plate slides a bit on its mount.
The bolts holding the faceplate are adequate, but don’t quite fit flush. The firm volume pot grinds a bit on its post: nothing a twirl of the Allen bolt won’t fix. (The torque necessary to twist it is Cloud Nine’s first, and last defense against burning eardrums. And it is way better at that the pot on most portable amps. Applause.)
I guess that’s the problem with moon boots. They look freaking awesome in the club. But your feet? Sweaty messes. Cloud Nine looks great, looks like a car from your childhood, but those looks are accompanied by a few comic bookian quirks that really should be ironed out.
That’s to say that Cloud Nine does NOT say: I’m German-engineered. Nor do they say: I’m haute couture. It says loud and shiny: I’m moon boots, bitches, and you’re in for a ride!
That’s all to say that I LOVE the aesthetic. It’s unique. It’s got this 80’s (1979 October counts, right?) kid dripping with nostalgia. But certain ergonomic compromises were made in the name of moon boots. Se la vie.
In case you forgot, I’m Headfi’s hiss king. Sssssssss! Sssssssss! I hate the stuff. It is the biggest reason I give the nod to the MZAK100 mod over the RWAK100, which comes quite a bit cheaper, and is backed by Vinnie Rossi, a long-time friend of portable audio. The MZAK100 simply doesn’t hiss.
And within reason, neither does the Cloud Nine. My hiss-proniest earphones are the Ultrasone IQ. They’ve made me hate some previously loved audio gear. And, yes, they do pick up background noise from the Cloud Nine. But, by the power of Greyskull!, it’s minimal. It is in fact, about on par with the latest generation iPod nano (of which I am a proud owner), which means: only the MZAK100, and maybe the Calyx M have less hiss.
Even when paired with the same Ultrasone IQ, the finger exercise machine that is the volume pot achieves perfect balance between left and right channels almost immediately. That said, its usable volume range, at least for my ears, and when paired with the same earphones, is contained within a 10º turn of the pot. Urbaner earphones will allow more leeway. But that is a problem 99% of portable amps have with the IQ. And Cloud Nine outdoes most them.
Amps with gains more appropriate to the IQ are:
PURE II (ahead by two hairs)
Portaphile Micro (ahead by three hairs)
Cypher Labs Duet (ahead by a half a hair, but far hissier)
Cypher Labs Picollo (simply amazing gain system for sensitive earphones)
Background noise doubles and trebles when switching gain from medium to high. But it is completely commensurate to the power it outputs. Your DT880/600 won’t be bothered by the worst the Cloud Nine can do.
Even on low gain, they can kick out solid, unperturbed, and powerfully backed volume.
As for performance-by-numbers, Cloud Nine is impressive on almost all fronts. One: it provides plenty of current into low impedance loads to keep distortion to a minimum while managing pristine frequency responses. It is an excellent earphone amplifier. In the Sound portion of this review, I will describe what earphones are best suited to it. Low-current, high-voltage headphones like the DT880, to a certain extent, are Cloud Nine’s sweet spot. In particular, the stereo image is extremely wide, and the amp can scale up to the highest signal outputs.
In every single case, the limiting factor (RMAA, not my ears) was the output device, not the Cloud Nine. If an iPod, or an AK device puts out 90dB of dynamic range, so will Cloud Nine. If the iPod or AK puts out 85dB of stereo separation, so will the Cloud Nine. The difference will be that Cloud Nine will keep those numbers even under low-Ω loads, while the AK device will fall by at least 5dB in either metric, and the iPod: it depends. We are talking about a very high-quality output.
But it does sport a low-pass filter, smoothing peaks here, softening crashes there. If you’re a play-by-numbers type that must have absolute signal integrity, hit up the PURE II, which is even Stephen from top to bottom. If you’re in it for the simple pleasure that accompanies a favorite pair of headphones, a comfy chair, a smoldering fire, and whiskey on ice, you are in the market for a really nice low-pass filter. In the section below I’ll outline just how nice the Cloud Nine’s low pass filter is.
Back to power: in low gain, Cloud Nine supplies enough current-backed voltage to power a DT880/600, but only to levels that are slightly louder than safe. On high gain, volume levels safely jump up by ten to fifteen decibels. Those levels are too much for me. But, I know that many of you are in it for the hearing aids. If you’re intent on making this hobby a happy two-year affair before welcoming deafness, you will find that Cloud Nine can’t keep sizzle out of the bass when set to high gain past 3 o’clock on the volume pot. If you want to ruin your ears, other, more powerful amps exist.
But make no mistake: listening to DT880/600 at those volume levels WILL destroy your hearing. It is just a question of when.
By the way, I didn’t properly gauge battery life, but my excellent deductive mind tells me you can get around 30 hours to a charge, if not a bit more. That means like 50 whirls of John Denver’s Farewell Andromeda.
Sound and more continued after the jump: