Audio issues with iPad air through audio in on PX

[splinters]

Mentioned this over on the facebook page.

If I connect my ipad air to any of the audio inputs on the PX (1/8" or both 1/4") the audio from the iPad is crystal clear with no noise or distortion. However, if I connect the iPad to the PX via the camera connection kit (official) there is a noticable hum/buzz which is very off putting. I,had to drop the external audio volume to less than 50 just to bear it but anything above 1 and its noticable.

Another user has confirmed the same issues so I dont think its specific to my board...which was brand new today. I turned off high resolution midi but that didnt help.

Any ideas how to fix it?

[Ebonivor]

Splinters, I posted this comment on the Facebook group. You are not alone, so hopefully we can get some answer as to why this is not happening with all PX-5S units.

Here is what I posted:

"I noticed this problem with the buzzing a couple of weeks ago but just put it down to the possibility of a dodgy audio cable. Having read all the reports here, I thought I should pursue it further.

I have an iPad 2, iPad Air, iPhone 3GS and iPhone 5C, so I am able to test with both Lightning and 30 pin connector, plus, I have the Apple CCKs for both connector types. I also tried swapping several different cables.

Here are my results:

With both iPads, a short buzz follows a played note, however, it is not consistent but tends to build as more notes are played.

The iPhone 3gs causes a continual buzzing, although, it says that the CCK is an unsupported device.

The iPhone 3C is silent, except for a bit of buzzing if the Lightning connector is slightly jiggled.

To determine whether the buzzing was only evident in the output stage of the PX-5S, I decided to record a a few notes to the USB stick. I first tried this with the iPad Air.

The first thing I discovered was that there was a lot of buzzing as the USB stick mounted. I recorded a few bars of single notes, fast and slow, at varying velocities, plus a few chords, and found that the buzzing was continuous while recording. And yes, it was there on the recording when played back with the iPad disconnected. I had the same result repeating the exercise with the other iPad.

By the way, I should have added, that I tested with and without mains power ( with batteries), and alternating between the 1/8th and 1/4 inch inputs.

I have had the unit for a little over 3 months and it is running firmware 1.11. Since Scott, Brad and Paul seem to have had their PX-5S for a while longer and aren't experiencing the problem, I'm starting to wonder whether there has been a change in componentry, or, perish the thought, a drop in quality control."

[splinters]

Thanks for replying...are you saying you get a similar hum when inserting a USB stick. I cannot eliminate the hum whatever combination of inputs, cables etc. i use. Gonna have to reconsider the use of iPad with the board unless there is a fix that doesnt involve buying more equipment...or return the board.

[Ebonivor]

Splinters, I don't get the noise when I insert the stick - it's when I mount it, but only when I have the audio out from the IPad connected to the PX-5S while the keyboard's USB midi is connected to the iPad with the Apple Camera Connection Kit.

Mike Martin is saying that it's a ground loop caused by the inadequacies of the USB midi standard and that may well be the case, although some users are saying that they don't have the problem.

Today, I tried connecting the standard midi connections to the iPad via my iRig MIDI connector instead of USB and there was no noise, so I guess I'll use that until a better solution comes up. My iRig MIDI is the 30 pin model, so I have to use the Lightning adapter with it which makes it potentially fragile, and of course, i need to run two cables instead on just one. There is one benefit; the iRig MIDI has a micro USB connector for supplying power to the iPad.

There's a lengthy discussion about the issue on the Facebook page that you might want to participate in.

[Choppin]

1st, keep in mind any device that receives or transmits wifi or bluetooth has a high probability of audio interference.  

 

2nd, If the port output is anywhere near the internal antenae of the device, or if the antenae and the port share the same electrical circuit or are in close enough proximity, there could be buzz and interference.  If using a different adapter solves the problem then it's likely the device or the previous adapter.  it doesn't sound like a px-5s problem

[Brad Saucier]

Agreed Choppin.   All devices are different.  One may cause trouble and another may not.  Casio did their part by putting the USB jack far away from all of the audio connections.   If another usb gadget was not so thoughtful in it's design, then it may be causing noise.   Suggestion to end all noises....Use the traditional midi connections for midi and not the USB.  The ancient midi system is still tops when it comes to combating noise. 

[Ebonivor]

Choppin, your points are quite valid. I've worked with electronics for over 50 years in design, build and repair, so I've had my share of solving interference problems. I took all of this and more into consideration when I was conducting my tests.

 

I do believe that the problem has more to do with the design of the iPad circuitry than that of the PX-5S. I don't think that even Steve Jobs could have predicted the incredibly diverse demands that the iPad would be expected to fulfil. Sometimes we just expect too much... :-)

[splinters]

Ebonivor, ironically that is my post on Facebook (paul woodward) and I solved it the same way you did but I used an el cheapo midi to usb adaptor i bought off eBay years ago. Brad is right when he says good old MIDI is still the best way, i had a noticeable lag playing the iPad through the USB connector but none through the midi/usb.

It has actually solved another problem I would have had when I eventually connect to Logic on my macbook....i need the USB to drive logic and, given Midi will work independently of the USB, i can control the iPad at the same time.

Brilliant.

[Ebonivor]

That's great Splinters, and I'm glad you worked out the method of driving Logic at the same time. I hadn't got around to doing both at once - it's good to know that I can.

I hope you end up being happy with the PX-5S - from your photo, it certainly looks as though Casio built it especially to fit your workspace :-)

[splinters]

I hope you end up being happy with the PX-5S - from your photo, it certainly looks as though Casio built it especially to fit your workspace :-)

You know what, i think they did. Finally found a day to do something not work related so I am going to connect it all up; mac, ipad, px, speakers, and see what it can do...will try the editor and new sound packs too.

Thanks for the help.