Buzz from iPad audio when connecting a USB midi keyboard

[erik_nie]

Hope that someone can help me.

 

Buzz in my case is a higher pitch sound, not the typical 50/60Hz. Like a phone is too close.

 

My situation is as follows:

- We have a few songs with some backing tracks (mostly percussion, effects), stereo output is good enough: left -> audio, right -> click

- I have a iPad mini with an application that can play backing tracks, display chords/lyrics and can send out midi program changes (made this myself, but could be any of the usual suspects)

- In a first version I did not use the program change output and just plugged the iPad into the charger and use the audio out from the iPad to my mixer. This was 100% clear and no buzz.

- When added the option to send program changes and connected my midi board (Nord Stage 3 compact) I noticed a high pitch sound on the audio out of the iPad. When I took out the USB cable it was 100% clear again. Connection via the official Apple connection-kit with charger input, so it can work all night during a gig.

- I have a no-name USB-audio interface, so I added a none-powered USB hub where I connected the Nord Midi and the audio interface. The buzz was less and almost acceptable. Again: removing the midi USB cable did remove the buzz completely. That no-name USB interface was already a few times a lifesaver/backup for my old Laptop rig.
I changed the cables and USB Hub with anothers, and have a short USB cable with ESD-Coil.

 

I think this is pretty straight forward setup and other might have similar issues. Hope that there is an solution for this.

 

I could think of:

- using a high-end iPad audio interface. This might be expensive, bulky, overspec'd, another wall-wart,...

- Battery only iPad. This makes me nervous, as we play 4 sets of one hour

- Balanced USB cable. Do they exist?

- Using a DI box. I have two small audio transformers that I could put in a small box.

- ????

 

The level is now almost acceptable and I played a gig with it.   

 

[Kawai James]

Two other options to consider:

 

1. Use a USB to MIDI IN/OUT adapter (e.g Roland UMone etc.) to connect the Nord to the iPad.

2. Use a ground loop filter in between the iPad and the amplifier.

 

Cheers,

James

x

[emmabruj7]

So whenever I have an application open on my MBP that uses MIDI (like Logic, Finale, DP, etc) and I have a USB MIDI keyboard plugged in and on, I get an audible hiss/buzz from my headphones or monitors. It's like the noise floor shoots up radically. It doesn't matter if the keyboards a USB-powered or not (plugged into the same outlet as my MBP or not) or whether the MBP is plugged in or not. If I turn off the board then it goes away. The weirdest part is that as I am typing this right now, when my fingers contact the MBP, the noise improves right away and when I take the keyboard off my lap, it gets better too. Anyone lese have this or ideas how to fix it? Is an external DAC a solution? 

[erik_nie]

1 hour ago, Kawai James said:

Two other options to consider:

 

1. Use a USB to MIDI IN/OUT adapter (e.g Roland UMone etc.) to connect the Nord to the iPad.

2. Use a ground loop filter in between the iPad and the amplifier.

 

Cheers,

James

x

 

Thanks for the quick reply.

I have two Nords that are midi-connected to each-other, so no free midi port. (Use the organ-section in the Stage 3 to be played from the Wave 2)

Could you point me to a small ground loop filter?

[erik_nie]

1 hour ago, Kawai James said:

Two other options to consider:

 

1. Use a USB to MIDI IN/OUT adapter (e.g Roland UMone etc.) to connect the Nord to the iPad.

2. Use a ground loop filter in between the iPad and the amplifier.

 

Cheers,

James

x

 

I saw your post (at the same time as mine), the bluetooth midi connectors could be a solution:
Could buy two of them and use them for inter-midi between my two synths (using a iPad application MidiFire) and also use it for sending the program changes.
I'm a bit creepy of the use of wireless connection for live midi, the program changes will  most probably work. Still, wireless is not preferred.  
Could make my setup time quicker.
Not sure about the reliability and the latency of this option... any users out here that have a similar setup or use the Quicco Sound mi.1 II?
I could remove the camera connection kit and just use bluetooth.

[Kawai James]

14 hours ago, erik_nie said:

 

Thanks for the quick reply.

I have two Nords that are midi-connected to each-other, so no free midi port. (Use the organ-section in the Stage 3 to be played from the Wave 2)

Could you point me to a small ground loop filter?

Something like this?
https://www.amazon.com/s?k=ground+loop+isolator

I don't have any personal experience of using these, however I know some folks have had success with them, typically when playing VIs on a laptop controlled via USB-MIDI, then routing the sound back into a digital piano via an instrument's Line In connectors.

 

Regarding the QuiccoSound, I have both the original mi.1 (as in the very first Indiegogo backed device) as well as the latest mi.1 II, which has even better latency.

I haven't used it for gigging yet, but this is ultimately what I intend to try once my new iPad arrives.  I'm hopeful that it will work for playing (the latency playing VIs on my Mac is pretty acceptable), so should be absolutely fine for just sending PGM# messages.

 

Cheers,

James

x

[emmabruj7]

I have suggest you to one website techters which have all the information about the pc  and my personal experience is on many digital musical instruments you find two USB connectors - one Type A connector labeled To Device and one Type B labeled To Host . The To Host is usually used to send MIDI, Audio or both Audio and MIDI to a computer, smartphone or tablet.

[AnotherScott]

Some people have also modified the USB cable, cutting the ground wire.

[D. Gauss]

On 7/20/2022 at 4:07 PM, AnotherScott said:

Some people have also modified the USB cable, cutting the ground wire.

 

For anyone having a USB iphone/ipad noise/interference problem, this solved it for me:

 

  You have to remove the connections to the 2 outside pins on a USB cable.  I have a casio CDP-s150 with USB midi out going into an Iphone 6 (headphone jack!) with camera adapter kit running Pianoteq 8. All are powered via the wall, no batteries. The Iphone headphone jack is connected via 1/8" audio cable to the audio in on the Casio.  It was unusable due to deafeningly painful digital noise.  I tried lifting the ground/shield on the audio cable, no luck.  Moving to a battery pack for the Iphone lowered the noise some, but still terrible.  USB cable with ferrite beads did nothing.  Removing the pin 1 connection on the USB cable did not work either.  BUT.... removing the connections to the 2 outside pins on the USB cable resulted in glorious, noise free, midi controlled Iphone piano.

 

Easiest way to test this without cutting wires, soldering, ruining your cable, etc... hopefully i explain this clearly:

 

-get a piece of printer paper

-cut a strip that is just wide enough to fit inside the end of a USB cable. (about a 1/2" and maybe inch and a half long)

-now cutout a 1/2 inch "U" in the end of the strip so it looks like the devil horns, heavy metal hand gesture. Like 2 little legs/fingers.

-insert the paper into the USB end, fold over the excess and plug it into your interface, camera kit, whatever.