Connecting a digital piano, an iPad, an audio mixer and headphones

I recently bought a Yamaha P-115 Digital Piano (which I love) in an attempt to teach myself to play piano. Its piano sounds are amazing and the graded-hammer-action on the keys really do feel like an acoustic piano.

I quickly discovered there are some really great apps available on iOS for learning piano and the majority of them allow you to connect your iOS device to your digital piano via its MIDI port. This means the app can check which keys you’re playing and help guide you though your piano lessons.

A great example of this is Simply Piano by JoyTunes.

Simply Piano on the App Store   Simply Piano on Google Play

Learning to play with the help of an app is all well and good but to anyone in the house, having to listen to someone bashing away on a piano with some cheesy backing music or the app chatting away, can be pretty annoying.

I’ve read reports of people actually wearing two pairs of headphones – one in-ear and one over-ear so they can hear the app and their digital piano at the same time!

I’ve come up with a solution that allows me to play the piano, listen to its amazing natural sounds and listen to training app on my tablet at the same time – all through a single set of headphones – and without disturbing anyone*.

I’ll go through the kit I’ve used and how I’ve configured it.

* Apparently the sound of me hitting the piano keys still reverberates through the floor and my foot tapping to keep time still annoys the rest of my household.

Here’s a list of the kit I’m using

I must stress here that I’m using an iPad Pro, so some of the information here is iPad specific. If you’re using an Android tablet it should be the same except for the need for an Apple Lightning to USB Camera Adapter.

Yamaha P-115 Digital Piano
Any keyboard or digital piano with a USB MIDI interface will work here. Most use the larger USB-B connector, but some use the mini and micro USB connectors. Be careful with these as they can be easily dislodged.

If your piano has more traditional 5-pin DIN connectors, you’ll need a MIDI to USB adapter like the iRig Midi 2 UNiversal MIDI Interface.

Male USB-B to male USB-A cable.
If your keyboard or digital piano has a different connector, you’ll need a different cable. Whatever you get, it must have a standard male USB-A connector on one end. This plugs into the Apple Lightning to USB Camera Adapter.

Apple Lightning to USB Camera Adapter
This connects to your iOS device through its lightning connector and allows you to plug in a cable with a USB-A connector. It also has a lightning socket so you can charge your iOS device at the same time. You’ll need a second lightning cable to do this.

This is expensive for what it is and there are cheaper alternatives out there. However these cheap versions are very poorly made, have bad internal connections and fall apart. I’ve tried some of them and ended up throwing them away after a couple of days.

Worse case, they could damage your Apple device or invalidate your warranty.
Don’t scrimp here – go and buy the right tool for the job.

Male 3.5mm to male 3.5mm stereo audio cable
You’ll need one of these to take the audio from your iOS device to the audio mixer. An angled connector is also a good option and can keep the cables a bit tidier.


Male 6.35mm (¼”) to male 3.5mm stereo audio cable
This will connect the headphone output of your keyboard to the audio mixer. If your keyboard has a smaller 3.5mm headphone socket, then you’ll need another 3.5mm to 3.5mm stereo audio cable (like the one above).

If you’re really lucky and your keyboard has an AUX output, then definitely use that instead. My Yamaha P-115 has a pair or mono 6.35mm AUX sockets on the back, so I use a cable with 2 x male mono 6.35mm to a single stereo male 3.5mm connector.

Simple stereo audio mixer
This is the key part of your setup. This is where the audio from your iOS device and your keyboard is mixed and sent to your headphones.

You’ll need a mixer that allows at least 2 x stereo audio inputs and a headphone output. This particular one has 3 x 3.5mm stereo inputs and a 3.5mm headphone output – which is perfect for what we need. It can be powered either by a couple of AA batteries (!) or via a micro USB cable.

Hooking it all up

Here’s how it all fits together

Configuring audio levels

I tend to set the audio on my iOS device to a maximum of 50% using it’s volume buttons. This reduces the strength of the signal to the mixer.

If you’re using the headphone output of the keyboard, you should set its volume to 50% for the same reason. If you’re using the AUX output on your keyboard, this will be delivered at an industry-standard level so you don’t have to worry about the output volume.

The mixer has input volume and gain settings for each channel and an output volume. I’ll assume your iOS device is using channel 1 and the keyboard is channel 2.

Here’s how I set mine up:

  1. Make sure everything is connected-up but turned off
  2. On the mixer:
    • Set the channel balance dials to zero i.e. equal left/right balance
    • Set all the channel volume sliders to zero
    • Set all the gain and AUX dials to 50%
    • Set the output (master) volume slider to 100%
  3. Turn on your iOS device
    • Set the volume on your iOS device and keyboard to 50%
  4. Turn on your keyboard
    • Set your keyboard volume to 50% (or zero if you’re using AUX output)
  5. Turn on the mixer
  6. Put on your headphones
  7. Set some audio playing on your one of your piano apps on your your iOS device
  8. Slide the volume slider of channel 1 (iOS device) up until it’s at a level you like.
  9. Play a few notes and chords on your keyboard while sliding the volume of channel 2 (keyboard) up.

Find a mix of channels 1 and 2 where you can hear the iOS device and your piano notes clearly. I like the piano channel (2) slightly louder so I can hear myself clearly while playing along with backing tracks.

Getting rid of the hiss, hum and crackle

You will hear some hiss, hum and crackle through your headphones.

Before fiddling with the mixer, try changing how your cables are laying and what they’re near i.e. power cables, chargers, adapters, speakers etc. Moving the cables can change the contact between plug and socket and 3.5mm jacks are particularly prone to bad connections.

To reduce any residual hiss, hum and buzzing, use the gain dials of both channels to find the sweet spot where it disappears. Adjust one channel at a time.

Each channel’s gain dial controls the input volume into that channel. Each channel’s volume slider controls the output volume of that channel.  The master slider controls the overall output volume of the mixer to the headphones.

Increased gain will increase the output volume of that channel, so you may need to adjust the channel’s volume slider down slightly to stop things getting too loud.

Once you’ve set one channel, the second channel is much easier. Just turn the gain dial until the hiss disappears completely. Again, tweak the volume slightly as the gain affects the volume.

In this particular mixer, the channels are not completely isolated and insulated from one another. This means changing the gain and volume of one channel can cause hiss and hum in the other. After a couple of minutes of slightly changing gains and volumes, you’ll soon have a nice clean mix.

I’ve included a diagram of roughly how my mixer looks for my setup of a Yamaha P-115 and iPad Pro.

15 thoughts on “Connecting a digital piano, an iPad, an audio mixer and headphones”

  1. You saved my P-115. So simple, yet, I couldn’t find much guidance until I found this page. Thank you. Still wondering why YAMAHA does not provide two-way MIDI connection on the P-115 whereas it does it very well on the PSR series. Now I can use Yousician again…

    • Behringer Q502USB Xenyx MixerHi Aaron, I’m glad you found the article useful.

      Since writing it, I’ve updated my mini-mixer to a slightly more advanced one which has a USB audio input. This accepts the digital audio from my iPad which eliminates the noisy iPad headphone connector and helps with the input levels as it’s essentially line out from the iPad.

      The high-quality controls, the DAC, the professional connectors and the internal mixing circuitry is also much better which I find results in a much purer and more “predictable” sound.

      The mixer I’m using is the Behringer Q502USB Xenyx.

      It does mean I have to introduce a powered USB hub into the mix though. Depending on the power and capabilities of the hub, you might find you can eliminate the Apple USB Camera Adapter as the hub is…

      1. powering the iPad
      2. passing MIDI data from the iPad to the piano and vice-versa
      3. passing digital audio from the iPad to the mixer

      Your mileage may vary here.

  2. Wow, this is involved. Just using the ipad headphone output without the mixer gives the exact same quiet training effect (you hear the piano and the instruction/music). The only downside is that the sound is what the iPad generates out of the Midi signal, so it sounds slightly different, but with much less clutter and fewer cables. Nice solution but I am sticking with the simpler setup (right half of your drawing). Thanks for sharing and explaining everything.

    • I agree, a much simpler setup would be to just plug your keyboard into the lightning port of your iThing and plug in some headphones (assuming you still have a headphone socket). This will work if whatever app you’re using also generates sounds in response to the MIDI signals received from your keyboard – that your are happy to hear – and this is the key point.

      Listening to app-generated keyboard sounds isn’t what this article is about.

      This article is specifically about physically mixing the sound generated by your app i.e. backing music or sound effects with the actual sounds from by your digital piano. If you’ve invested good money in an weighted 88 key digital piano which sounds amazing, then you’ll want to hear those sounds rather than the keyboard sounds from your iThing.

      I personally use both setups. At home with my Yamaha P-115, I use a mixer. When I’m away from home I use a lightweight portable MIDI controller which is powered from my iThing and I listen to the app sounds.

  3. Sorry I might have missed it but the iPad Pro doesn’t have a headphone jack and the lightning port is used for the camera adapter. How did you connect the iPad to the mixer?

    • Hi Preston,

      You’re right, this article was written before Apple dropped the headphone socket from iPad Pro’s.

      I addressed this in a reply to Aaron in October 2018.

      TL;DR; Use a powered USB hub and a cheap digital mixer (like the Behringer I mentioned). Route everything through the hub. You then plug your headphones into the mixer.

  4. Adrian, first off: thank you (!) for taking the time to do this. Alas, I’m still a little lost with the new iPad changes and would love it if you can help me out with a little step by step.

    Here’s what I’ve got
    – A Roland FP-30 with aux and USD outputs
    – the newest iPad with only a lightning output
    – Simply Piano app (which needs to hear the piano notes to say correct/incorrect)
    – headphones

    The goal here is obviously to hear everything through the headphones so no one else in the apartment has to listen to me play and I can hear at full volume on my headphones.

    Is the following correct?

    – route output sound of iPad via lightning adaptor/aux cable to mixer
    – output of piano sound via USB to mixer
    – headphones into mixer

    But how does to the iPad app “hear” the piano? And can you recommend a USB hub so I can order one online that will work for this setup? Sorry I’m new to all of this. I can’t believe no one else has addressed this issue online and I’d be very grateful if you could help me out! I’m sure I’m not the only newbie trying to get technical and figure this out. Thanks!

    • Hi Marcus,

      Thanks for your message.

      Yes, you’re right in your statements, although it’s important to understand that your digital piano isn’t actually sending sounds to your iPad to “hear”, it’s actually sending MIDI data i.e. a coded digital message saying which key was pressed and how hard. This is how Simply Piano knows that you’ve pressed the right key at the right time.

      Here’s a connection diagram:

      USB Digital Piano, iPad, Mixer connections

      It’s important to find a powered USB hub that will work with your iPad, mixer and digital piano. I have this mixer: Behringer Xenyx Q502USB USB Audio Mixer and this USB hub: AUKEY USB 3.0 Hub.

      The hub is particularly good (for me) as it’s USB 3, has a built-in Gigabit Ethernet port (which works on a MacBook Pro) and a high-capacity charge-only port (the green one) which is great for fast-charging an iPad. Don’t connect anything to this port if you want to transfer data though, otherwise nothing will happen! 🙂

  5. Hi Adrian,
    Thanks a lot for your article.

    I’m using ipad pro with usb-c connection, can I just connect this ipad to P115 by USB-A to USB-C then use AirPods to get both sounds from Simply Piano and my P115?

    Is there any special set up with above system to really get SimplyPiano “hears” P125?
    Thank you so much.

  6. Thanks for your post. I’ve been racking my brain trying to figure out how to listen to my keyboard and iPad/iPhone at the same time through headphones. I have a Roland FP30 that connects to my IOS devices through Bluetooth. How would that impact the setup? Is a powered hub still needed or would you recommend a different setup all together?

    • Hi Eric. If you’re using MIDI over Bluetooth, then there shouldn’t be a problem. You’d still need to run the audio out of your iPad and your FP30 into a mixer.

      Depending on the model of your iPad, you’d use either the headphone socket or the USB port (lightning or USUB-C).

      If you’re going by the headphone socket, a simple analogue audio mixer will do. If via USB audio, then you’d need a digital mixer with a USB port like the Behringer Xenyx Q502USB.


Leave a comment