Review: PlusSound Cloud Nine – A Second View

Disclaimer: PlusSound is an American company that mostly specializes in after-market cables. They however do also have their own portable amplifier the Cloud Nine. I got the amp free of charge for this review.

Cloud Nine

Ever since Nathan reviewed the PlusSound Cloud Nine (CN) I had been dying to hear one. PlusSound got word of that and they decided to send me another Cloud Nine amp for review. At the same time I also got a superb Apollonian+ IEM cable I have been using with the Earwerkz Legend R, an Apollonian+ cable terminated for Audeze that I have been using with my LCD-XC and an Echo+ Interconnect which has been my to go to interconnect since I got it.

When you look at Nathan’s gorgeous pictures of the Cloud Nine, you can immediately see it’s a pretty basic amplifier. It doesn’t have the fancy enclosure of an ALO or CypherLabs amps and it’s more of a back to basics kind of unit. I quite like that approach. The Cloud Nine is a simple looking portable amplifier intended for use with In-Ear Monitors and low and high impedance headphones. The Cloud nice was designed primarily on improving sound quality and pretty much explains why it has such basic but lovely enclosure. The anodized aluminium shielded enclosure, volume knob, and screws are custom made specifically for Cloud Nine.

The Cloud Nine isn’t the smallest of portable amps and it measures about 2.3″ x 4.5″ x 0.95″ and weighs 3.2 oz (without batteries). The CN actually is an 18V (2 x 9V!) battery powered amp. The down side is that you will have to change out the batteries. That means either replacing the stock delivered Duracell or buy rechargeable ones like I did. I have a mixed feeling with the choice for the 9V batteries but the upside is that you get an extremely effective, powerful and clear sounding amplifier in return. I was pleasantly surprised by the durability of the 9V batteries: I expected them to die on me under 10 hours but I’ve listened to it a whole lot and can you believe I’m still on the original set? All 9 volt batteries (Alkanine, NiMH, Lithium) will work with this amplifier and it can run from 20 hours to 80 hours. Expect long battery life, seriously!

A related down side of the Cloud Nine using 9V batteries is that they have to be easily accessible to change them out. To allow this PlusSound decided to use a thumbscrew system on the back and well it looks awful as we’re not used to seeing that on modern day amps. Then again, contrary to Nathan, I found these thumbscrews very easily accessible and easy to use. Sure it doesn’t look stellar and you can’t put the Cloud Nine up straight but it sure is handy.

The Cloud Nine has 3 gain stages (1x/0dB, 5x/10dB, 10x/20dB) and because of it sounds superb with all my gear from my most sensitive custom IEMs to the hardest to drive HE-500 Hifiman. On the inside you’ll find a precision amplifier followed with dual mono operational amplifier integrated circuits in the output stage. I have to admit I have a soft spot for Dual Mono designs. The entire amplifier goes through cryogenic treatment to improve durability and sound quality but I’m not really convinced of the whole cryo treatment myself.

Does it live up to its expectations?

With a power rating of 1.28W into 32 ohm, 1W into 50 ohm, 250mW into 300 ohm and 120mW into 600 ohm you can clearly see the Cloud Nine is no slouch, it’s extremely powerful for a portable amp of its size. Not only is it powerful: THD:~0.0009%!

Sound on Page 2

Review: PlusSound Cloud Nine – A Second View
4.4 (87.06%) 17 votes

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Lieven is living in Europe and he's the leader of the gang. Coming from a musical family he's always been interested in good sound. Unlike his family members the only musical instruments he plays are amps and DACs. He loves playing with old tubes and discovering new products while staying faithful to the good old Sennheiser HD650.

17 Comments

  • Reply June 18, 2015

    George Lai

    I presume those two screws jutting out at the back are for opening to change batteries, so I don’t understand why Nathan said it’s inaccessible. Can you include a couple more pictures on how the battery looks like inside the device? Thanks.

    • Reply June 18, 2015

      Headfonia_L.

      He must have huge fingers

    • Reply June 18, 2015

      dalethorn

      It has to be better than the Decware Zen Head. That one is difficult enough to get a 9v in and out of, then if you just happen to touch the terminals in reverse, it immediately fries the chips.

    • Reply June 19, 2015

      ohm image

      They are very small screws and the batteries bulge backward, forcing the rear door against the screws. They are much harder to turn than had they been larger screw tops. My fingers are slim.

      • Reply June 19, 2015

        Headfonia_L.

        I really have no problem at all with the screws, I just have to make sure not to drop them 🙂

  • Reply June 18, 2015

    Lofthanza Art

    Is the Fiio X5 ii a bit brighter than the dx90?
    And is the amp section of the Fiio better than that of the dx90?

  • Reply June 19, 2015

    Miguel Garcia-Guzman

    Great review, indeed, it complements very well Nathan’s review. Based on your description I think I may get the Cloud Nine or the Vorzüge PURE II . I have a Noble K10 and I am looking for a good amp that works well with the K10. It seems that Nathan likes both the Cloud Nine and the Vorzüge PURE II with the Noble K10.

    I have two questions to chose between the Cloud Nine and Vorzüge PURE II

    Question1: of the two amps which one pulls the best of the Noble K10?
    Question 2: I assume that these amps are shielded and there is no problem in using an iPhone for possible wifi/LTE signal interferences in the sound. Is that correct or I will need to use the iPhone in airplane mode to avoid electrical effects on the amps when playing music?

    Thank you!

  • Reply January 23, 2016

    Gabriel Ross

    L.and N. If I could please gush for a moment. If not for Headfonia from year to year. I would not have, the set up I have today. Thank you. Mid-Fi I know, but at it’s best :] Forza usb, Fostex A4, Forza ,Cloud nine[as desk top],Forza, L2’s. Have a great 2016.

  • Reply February 19, 2016

    Juan Luis Quiroz Guevara

    How compared with cypher labs pocollo?

    • Reply February 19, 2016

      Headfonia_L.

      Same type of full bodied sound, but don’t forget the picollo is an IEM amp (even if it works quite well with some fill sized cans). Picollo is the most silent one

      • Reply February 19, 2016

        Juan Luis Quiroz Guevara

        If not a user iem , but would need to use an amplifier for portable cans and home headphone as he400s . ¿What amplifier should choose? ¿Picollo or Cloud nine? Sound quality being my priority.

  • Reply June 11, 2016

    Gabriel Ross

    L. I don’t [hear] a problem, but to run my new Fostex Mk3’s. I am running my Cloud Nine [low gain for best sound] full open; using my A4 dac as vol. control. Is full open OK, on the CN? Old fan.

    • Reply June 11, 2016

      Lieven

      I’d always put the DAC full open (=0dB gain)

  • Reply January 28, 2017

    Joel

    Hi, I hope this amp is still open for discussion. The description reminds me a lot of the original Headamp Pico, which I have heard. How similar are the two? If the Cloud has a similar tonality minus the congestion that I did experience with the Pico then it may be something for me to consider. I just loved the way the Pico sounded with female vocals. Thank you.

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