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New iPhone Pro (w/o headphone jack) and a USB battery powered rig

McDMcD
edited March 2020 in App Tips and Tricks

I got a new iPhone without the headphone jack and wanted to use a Powered USB hub to connect:

  1. A USB bus power Audio Interface with a headphone jack
  2. A USB MIDI keyboard controller
  3. A USB Guitar audio interface (optional to allow more audio in's on the audio interface like Mic's)

I wanted to power the whole "USB Network" of devices with a battery so I bought one of the new
Battery Units that outputs a port of 18W 5V.

My USB hub would only work with a wall power adapter but today a 5V barrel adapter showed up that brings the Hub up off the single 18W power port on the new battery and everything connected to the hub lit up.

Finally audio in/out with headphones and MIDI controllers (the HUB has 8 USB ports).
Everything I connect is visible in AUM and not a single connect to wall power.

Now how long will the 18W battery drive the whole rig... it's rated at 20,000 mAH.

Comments

  • Verdict ?

  • edited March 2020

    18W, 5V would mean 3.6A can be delivered from the hub (max). Which sorta makes sense. A lot of hubs allow for 2devices to be plugged in.

    Assuming it's a USB 3.1 HUB, it should draw a maximum of 900mA.

    So, at 900mA, you're 25% requirement from the max. Since the voltage is the same, you're good.

    So, to answer your question, at full charge, and assuming the battery has 100% of its charge cycle,

    20000mAH/(900mAH) = 22.2 hours of use (approximately)

    Depending on how much power your hardware draws, you might not be able to use all the ports.

  • @Samflash3 The Hub is fed 4A from the wall power adapter and 3.6A from my 18W battery pack.

    I connect the HUB output USB A cable into the iPhone CCK's adapter. I also like to cable up the CCK's lightning power port to the Battery as well on an optional 2.4A port in the Battery pack to reduce the load on the Hub.

    So, I'm expecting I can provide power to 4 USB A connected devices. Currently I have tested
    two MIDI keyboards and 1 Presonus USB Audio Interface. I'm trying to find my USB A to iRig HD so see if I can see it as an additional audio interface in AUM.

    I think charging up the battery to 100% and and seeing how long everything stay "lit" will
    be a reasonable way to gauge the current being consumed in total.

    The specs on the USB Hub state:
    USB 3.0 Hub with wall power adapter must not exceed a combined current of 4A.
    *I'm probably sourcing 3.6A max as you suggest from the Battery units "Quick Charging" 18W port.

    The Hub provides 7 USB 3.0 data ports with maximum output current of each USB 3.0 data port is 0.9A

    And 1 smart USB charging port to provide current up to 2.4A (maximum output of any USB 3.0 charging port) for charging your mobile phone,camera and any more USB devices.
    Provide a 5V/4A power adapter that help transfer data more stable.

    • I use this charging port into the CCK Lightning port

    I need to find that iRig custom cable before I run a timed trial to gauge the total current draw.

  • McDMcD
    edited March 2020

    I need to find that iRig custom cable before I run a timed trial to gauge the total current draw.

    AUM doesn't offer the Presonus Audio ports as options when the iRig is active so I have just plugged the guitar in an audio port in the Presonus and added a Phantom Power mic on the other port.

    A lot of people assume that 48V phantom power assumes a lot of "power" but the reality is that it's a "charge" voltage intended to create an electro-magnetic field between the plates of the mic and you need very little current to charge up the potential of 48V's using a step up transformer.

    So, I have the MIDI keyboard, Phantom Powered Studio mic + Guitar into the Presonus audio interface using only 2 USB ports on the hub. So, I could add more USB MIDI devices for knobs or more keyboards.

    I started with 81% and drew down 15% in about 3/4 of an hour. It the discharge rate is linear this could last about 5 hours on a full charge so I'll probably see another 3 hours before the lights go out around 9.

    https://forum.audiob.us/uploads/editor/wq/1bu656lxlol8.jpeg

    The iPhone Pro is being used to take the photo.

  • @McD said:
    So, I'm expecting I can provide power to 4 USB A connected devices. Currently I have tested
    two MIDI keyboards and 1 Presonus USB Audio Interface. I'm trying to find my USB A to iRig HD so see if I can see it as an additional audio interface in AUM.

    >

    I need to find that iRig custom cable before I run a timed trial to gauge the total current draw.

    You can only use one audio interface with iOS at a time, so you might as well skip trying to use both at once. I think it’s always the last one plugged in that is the one that gets used.

    Neat idea though. I got a 20,000 mAh battery pack as well recently. It has USB C and USB A. It supports PD as well, so it should be able to fast charge my iPhone 8 and iPad Pro. I just bought a generic Anker cable so maybe it won’t actually fast charge that fast.

    There are also some USB hubs that you don’t need to get an adapter for uGreen makes a few where you just plug in microUSB and it powers it. I have one, but never really put anything with a heavy load on it. A hub powered by USB C might be a good option as it provides more power.

  • @DMan said:
    A hub powered by USB C might be a good option as it provides more power.

    This hub I got has a USB C port 2. It and the fast charging USB A port are both blue while the
    standard port is black. The Hub is rated to support up to 4A's worth of devices before it protects the wall adapter.

    I/O Specs for the battery are:

    3-input - micro usb; usb c; Lightning port
    3-output – usb c; usb 3.0; usb 2.0

  • Had a feeling my math would be wrong. Wasnt sure if it was 900mAh per port or overall.

    Also, sick setup. Have the same Akai keyboard amd I've been planning to use it as a dynamic midi pedal for my guitar with the drumpads but never got around to setting it up.

  • McDMcD
    edited March 2020

    @Samflash3 said:
    Had a feeling my math would be wrong. Wasnt sure if it was 900mAh per port or overall.

    Thank you for commenting.

    There was some useful details in here to help think through the P = I x E relationships.

    Power = Current (I) x Voltage (E).
    Current = Power / Voltage
    Voltage is always 5V in this situation.

    P is Power (18 Watts for quick charge ports and typical USB A devices at 4.5 Watts)

    Trivia buffs:

    The conventional symbol for current is I, which may seem puzzling. It originates from the French phrase intensité de courant, or in Englishcurrent intensity. ... The I symbol was used by André-Marie Ampère himself, after whom the unit of electric current is named.

    The scientific symbol for voltage is an "E", dating to early days of electricity when it was called the "Electromotive force".

    Hence P = I x E.

    Also, sick setup. Have the same Akai keyboard and I've been planning to use it as a dynamic midi pedal for my guitar with the drumpads but never got around to setting it up.

    FYI: the lower C key barely functions unless I smack it. But I bought it to play with programming knobs and pads in Mozaic. If I do much in that area I'll buy something much better for that purpose. The keys, pads and knobs will give be a lot of triggers for Mozaic input purposes.

    I pulled the power on the test run after 3 hours and 30 minutes: consuming 45% battery of the effective battery maximum.

    I think the IK Multimedia iRig Pro with stereo audio in/out and optional 5 pin MIDI in/out would be good for an even more compact mobile studio replacing the Presonus USB AudioBox. I could easily velcro the parts to the front of the Tele' and put the battery in a pocket and hang a speaker from by belt.

    I am so glad someone mentioned the barrel connector option (jn another thread) to light up the powered USB Hub from a quick charge port.

  • Welcome to my world!
    I find Korg nanokontrol mk1 and mpk mini mk1 the best low power controllers.
    However I’m trying a new set up below

  • @supadom said:
    Welcome to my world!
    I find Korg nanokontrol mk1 and mpk mini mk1 the best low power controllers.
    However I’m trying a new set up below

    The Novation Launchkey 3 seems to be the better replacement for the Akai. At least that's what I've heard.

  • @Samflash3 said:

    @supadom said:
    Welcome to my world!
    I find Korg nanokontrol mk1 and mpk mini mk1 the best low power controllers.
    However I’m trying a new set up below

    The Novation Launchkey 3 seems to be the better replacement for the Akai. At least that's what I've heard.

    It needs a powered hub or a bank to work. Also the pads are small and only send notes and not ccs. I’m about to sell mine.

  • @supadom said:

    @Samflash3 said:

    @supadom said:
    Welcome to my world!
    I find Korg nanokontrol mk1 and mpk mini mk1 the best low power controllers.
    However I’m trying a new set up below

    The Novation Launchkey 3 seems to be the better replacement for the Akai. At least that's what I've heard.

    It needs a powered hub or a bank to work. Also the pads are small and only send notes and not ccs. I’m about to sell mine.

    Wait, really? I see.
    My main gripe with the Akai is just the arpegiators. Can't seem to make the most of it on iOS. Also, getting used to the pitchbend.

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