New Portable Amp - "Pocket Class A" by xrk971 - now available as complete PCB

  1. xrk971
    Thanks for the order! Let's customize for you now.
  2. Mboom
    For the DIY kit, What kind of soldering iron do you recommend to use ? Ive only soldered a few things year's ago.
  3. xrk971
    Nothing fancy, but I personally like a moderately small chisel tip like this:


    Watch some YouTube videos on how to do it. Basically solder one end first while holding it with a good tweeter. Then solder other end.
    Solder paste from syringe works well too - use hot plate and cook on medium heat for about 2 minutes until all paste liquifies and forms neat fillets.

    A basic kit like this with variable temp and good collection of tips will work just fine.

    GHB Soldering Iron Kit Micro Soldering Kit 110V Adjustable Temperature Electric Iron Sets for Various Repairing Usage
    Last edited: Oct 15, 2017
    Mboom likes this.
  4. xrk971
    Thanks so much for the order!
    Lost Cosmonaut likes this.
  5. Lost Cosmonaut
    You're welcome -

    I wish you success with your amps!
    DBaldock9 likes this.
  6. DBaldock9
    ...especially the Balanced Desktop model... :wink: :ksc75smile:
    Lost Cosmonaut likes this.
  7. Lost Cosmonaut
    I'm discovering that the NHB takes full advantage of headphones that excel at producing midrange.... It's making me regret that I sold off all of my Audio-Technicas

    Luckily, the HD650 and the NHB are a match made in heaven and it also clicks with the Thinksound ON2.

    I can't wait to use it with the HE-4XX to take advantage of that planar bass.
  8. xrk971
    I just built a new one today and found that Nichicon KA 2200uF 16v audio grade caps (big fat blue ones) fit perfectly. I am bypassing on the other side with a Elna Silmic II 10uF 35v. Now this combo has the most output capacitance of any I have built as a pocket amp. Sure to please the deep bass, low impedance IEM crowd. Sounds very nice. Measures wonderfully too, here is 1000mVpp into 270ohms.

    SN034-2200F-AK-Photo.jpg SN034-2200F-AK-FFT-1vpp.png
    Last edited: Nov 20, 2017
    DBaldock9 and Slater like this.
  9. xrk971
    I built two just like this yesterday. I wish I could have kept one for myself but alas, one went out to a customer in Colorado. The other is on its way to New Zealand - you guessed it, to member Brooko for a review on Head-Fi. :)
    DBaldock9 likes this.
  10. DBaldock9
    Which batteries are you using with that new amp?
  11. xrk971
    Those are just Tenergy brand Alkalines that I ship out as standard with every amp I sell. It allows the customer to listen and enjoy immediately while waiting for rechargeables to arrive, and allows verification that all still works after shipping. Alkalines are nice in that you never have that auto-shutdown problem on startup due to in-rush which requires clicking on-off a few times.
    DBaldock9 likes this.
  12. xrk971
    My new commuter rig: Cayin N3, NHB Pocket Amp, and KZ ZS5v1 quad driver IEM's. Superb sounding combo.

    Thanks to @Lost Cosmonaut for the recommendation of the N3 - very happy with it!
    DBaldock9 likes this.
  13. krunchcrispy
    Just wanted to say that I got some EBL1200 mAh rechargeables to go with my ARKAudio NHB amp -- they are slightly bigger than the 600, and so fiddly to fit, but they will fit. And they last a good long time, too.
    Lost Cosmonaut likes this.
  14. xrk971
    Can you please give a link for the rechargeable 1200mAhr batteries? The only one I could find are EBL 9v 1200mAhr Li non-rechargeable batteries. These have a 10yr shelf life.
  15. DBaldock9
    When trying to find a single high-output 18V Li-Po battery pack (to substitute for the dual 9V batteries), all that seems to come up in searches, are the handheld drill batteries.
    I did find that one Chinese company that sells 18V Li-Po batteries, but they can't ship them into the USA any longer.

Share This Page