Tag Archives: iPad

Wired USB iPad rig

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After investigating a wireless iPad-based rig for church gigs, I decided to take a 180 and try wired! The urge was inspired by a recent thread in the MusicPlayer Keyboard Forum about taming the rat’s nest of wires that engulf our keyboard set-ups.

My approach goes all-in with MIDI over USB. Both the Korg Microkey Air 49 and the Boss EV-1-WL wireless MIDI expression pedal have full-size USB-B device ports, so it made sense to start with them and build out.

I really detest the iPad 3.5mm audio jack on my 3rd generation iPad Air. That may sound like crazy-talk to people owning phones and iPads without a 3.5mm audio jack. However, the jack’s placement exposes an inserted 3.5mm plug to all sorts of physical and sonic abuse. Every time I pick up or move the iPad, the jarred plug causes all manner of crackles, pops and hum — at loud volume, no less.

Thus, an external USB audio interface is a necessity. I pulled out an old Behringer UCA222 2-in/2-out USB audio interface, which was my PC audio workhorse for many years. (Now replaced by a Yamaha AG-06 mixing console and audio interface). The UCA222 is not the best interface, but it’s inexpensive. Sweetwater is selling these for about $10USD and you can’t go wrong at that price.

Based on my success with UCA222, I put a Creative Labs Sound Blaster Play 3 external USB sound adapter on order ($20USD). The Play 3 is even smaller and will do 24-bit, 96kHz given driver and control panel support. The Play 3 is not spec’ed as IOS compatible, but folks are having success with Play 3 and iPad.

For extra credit, I would eventually like to control IK Multimedia B-3X with a Crumar D9U DIY drawbar controller. The D9U hasn’t seen much action lately and it would be good to get it into the mix. The D9U can do MIDI over USB through its micro USB port. That particular test must await another rainy (snowy?) day as I need to adapt the D9U Arduino sketch for B-3X.

Well, if you were counting, that’s four (4) MIDI devices. The Apple Lightning to USB 3 Camera Adapter has only one USB-A host port. Uh, oh. We need a hub. Fortunately, I have a few Sabrent HB-MCRM 4-port portable USB 2.0 hubs on hand. The Sabrent HB-MCRM is small, light and cheap (less than $10USD).

One could use an olde style Apple USB Camera Adapter, but why put yourself through the agony? Better to have the Lightning charge/power port than fight electrical current restrictions. BTW, I wish the Belkin RockStar™ had three ports: USB-A host, Lightning charge and 3.5mm audio.

It’s not rocket science, so plug it all in and success! Core MIDI merges the MIDI input streams together. Korg Module Pro and Crudebyte iSymphonic Orchestra respond to the Microkey Air and the Boss EV-1-WL expression pedal. I expect the D9U to function correctly, too, if I get its sketch right.

                                 S   <---->  Microkey Air 49
                                 a 
                   Apple         b H <---->  EV-1-WL expression pedal
  iPad Air <---->   USB   <----> r u 
                  Adapter        e b <---->  UCA222 audio
                                 n 
                                 t   <---->  D9U drawbars

As to power, the EV-1-WL is not bus-powered. It needs either an external power adapter (9V 500mA center negative) or two AA batteries. The Korg Microkey Air and the Behringer UCA222 draw power from the Apple adapter through the Sabrent hub. (The Sabrent hub itself is not a powered hub, keeping things simple.)

A Lightning extension cable connects the Apple adapter to the iPad. This means only one cable to the iPad. The Lightning connector is reliably tight and eliminates the pops and crackles when moving the iPad. Most of the cabling sits on the floor out-of-sight.

As to audio connection, there are two options. Option 1 is running a long-ish unbalanced analog cable to the monitor. (The monitor is a Behringer B205D with a balanced XLR OUT to front-of-house.) Option 2 adds a USB extension cable between the hub and the audio interface (UCA222) for most of the distance with a short unbalanced cable from the interface to the monitor. Option 2 keeps things digital as long as possible, eliminating hum and other noise problems due to a long unbalanced cable run. Of course, there are limitations to USB extension (USB 2.0: 5M, USB 3.0: 3M).

Well, there you have it — an inexpensive, super-light, wired iPad rig. I haven’t found Bluetooth MIDI latency to be a problem, but wired latency should be less, if that is your concern. The USB approach seems to be less fiddly as to pairing, merging, etc.

If you’re curious about my wireless MIDI adventures, check out:

More blasts from the past about the Crumar D9U:

The Crumar D9U works pretty well with the Yamaha Reface YC, too.

Copyright © 2021 Paul J. Drongowski

Chord Tracker revealed

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I am using the Yamaha Chord Tracker app to figure out the chords to some tunes. Chord Tracker analyzes the music in an MP3/audio file and displays a chord chart. This is great for learning new tunes and working out arrangements.

Chord Tracker can do much, much more! Yamaha really needs to produce a manual for this app to reveal all of these functions. Here are some useful tips including how to send a MIDI file for a transcribed song to your Yamaha PSR/Tyros arranger for playback.

First off, you can change the chords in the chord chart. If you don’t like a chord, just tap the chord and select a new one. Chord Tracker does a pretty decent job of identifying chords in “simple” music. For example, it did a great job with Hot Chocolate’s “Every 1’s A Winner.” (My guilty pleasure.) It didn’t do such a good job with Groovy Waters downtempo “Wicked Game.” The jazz chords (Dm/Eb, come on, man) threw Chord Tracker off. No problem, just edit the chord chart.

Here’s a crazy idea. Use a DAW to produce a three minute song with one or two chords at the beginning. Transcribe the song with Chord Tracker. When you need to create a new song from scratch, edit the new chords. Presto, a chord chart editor.

Next, you can send the chord progression to your PSR/Tyros. The Yamaha web site touts wireless connection, but you can send the song file via wired USB. I transferred the chord progression to my S950 using the Apple Camera Connection kit. (My iPad is a gen 4 running iOS9, BTW.)

The Yamaha web page for Chord Tracker states that Chord Tracker is compatible with the currently listed “Related Products.” That is true. However, Chord Tracker worked successfully with the S950 (not listed). So, even though you don’t own the latest and greatest, please give this capability a try.

On the iPad side, you need to establish a connection from Chord Tracker to your keyboard. Plug in the Camera Connection Kit and USB cable first. Then select your instrument in the Connection box on Chord Tracker’s main screen.

Choose an audio song to transcribe to a chord chart and turn Chord Tracker loose. Once you have a chord chart, tap the upload icon, i.e., that square box with an arrow shooting upward. Then tap the “Send to Instrument” button. Chord Tracker pops up a dialog in which you can enter/change the name of the song file to be created on the arranger workstation. Tap SEND and Chord Tracker sends the song file to the arranger.

Chord Tracker stores the song file in the arranger’s internal drive. It creates a directory named “ChordTracker” and stores the song file in this directory. Any other song file that you create this way is stored in the “ChordTracker” directory.

Press the SONG SELECT button on the arranger to find and select the song file. Navigate to the USER tab of the internal drive and then press the corresponding button for the “ChordTracker” directory. Then press the corresponding button for the song file itself, e.g., “every1s”, which is the name that I gave to the “Every 1’s A Winner” song file.

Press the play button. The arranger will play back the song using the currently selected style and section. Now have fun changing the style, section, tempo and so forth. You can change the style, section, etc. in real time while the song plays, making it easy to tune the song to your sonic wishes.

Of course, you can dive into SONG CREATOR and tweak away. The System Exclusive TAB reveals much of the magic behind the scenes.

Chord Tracker generates three MIDI metadata records for time signature, key signature and tempo, followed by three System Exclusive messages:

    F0 7E 7F 09 01 F7             GM reset
    F0 43 10 4C 00 00 7E 00 F7    XG system ON
    F0 43 60 7A F7                Accompaniment start

The preamble is followed by a slew of Yamaha System Exclusive messages for the chord changes:

    F0 43 7E 02 34 00 34 7F F7    Chord control (F maj/F)
    F0 43 7E 00 08 7F F7          Section control (MAIN A ON)
    F0 43 7E 02 23 00 23 7F F7    Chord control (Eb maj/Eb)

Chord Tracker does not generate the Yamaha proprietary CdS1 chunk in the MIDI file. All playback is controlled by metadata and System Exclusive messages.

We can expect to see more of these kinds of features from Yamaha. They have a US patent (number 9,142,203) for a formatted chord chart and accompaniment generator. The generator is driven by a simple, free form text chord chart.

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