Connecting a Yamaha digital piano, iPad Pro, 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.

This 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.

So to get round this, I came up with a solution that allows me to play the piano, listen to its amazing natural sounds and listen to the iOS app at the same time – all through a single set of headphones – and without disturbing anyone*.

I’ll go through the list of kit I’ve used and how I’ve configured it. I’ll also recommend a few iOS apps I’ve been using.

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

Here’s a list of the kit I’m using

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.

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.

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