Maybe you would like to play your music in the great outdoors at a family picnic. Or, like me, you would like an extremely light, battery-powered rig for quick set-up at rehearsals.
Modern battery technology to the rescue! More musical instruments and portable speakers than ever run on battery power. Many of these devices sport an integrated rechargeable battery and a USB-based charge or power outlet. You can have that light battery-powered portable rig by combining a battery- or USB-powered keyboard with one of the many available portable speakers.
Here’s how I designed my portable rig.
I started with the KORG TRITON Taktile 49 USB-powered MIDI controller and synthesizer. The TRITON Taktile (TT) has 49 keys and is very light-weight (less than 8.5 pounds). The TT incorporates the Triton Classic sound engine and programs which are under the control of eight front panel knobs and sliders. I reviewed the TT here and here , so I won’t go into more detail about its sonic capabilities.
The TT does not have built-in battery power. However, it runs quite well on a rechargeable USB battery pack. USB battery packs are readily available and are usually intended to power or recharge personal electronic devices such as MP3 music players, phones, tablets and so forth. Fortunately, electricity is electricity and the TT is happy to operate on power supplied by a USB battery pack. As long as a battery pack can supply the necessary current (usually stated in milli-amperes or “mA”), the pack should be able to power any compatible musical instrument keyboard.
Let’s explore power requirements a little bit more, using the TT as the example. KORG claim that the TT draws 550mA of power through the 5 Volt DC USB-B port. I purchased an Incase Portable Power 5400 recharging “brick.” The Incase brick can supply up to 2.1 Amps (2100 mA) of current, more than enough to power the TT. The “5400” in the product name refers to the battery capacity: 5,400 mAH. In theory, the Incase 5400 brick should be able to power the TT for nearly 10 hours. (God helps us if we ever rehearse that long!) I have been using the TT/Incase combination during practice for the last few days under light use and haven’t burned off 20% of total capacity yet.
So far, so good. But, what about a portable speaker? Unfortunately, you can’t expect to drag your keyboard into Target or Best Buy and audition portable speakers. Most of the speakers on display in box stores are wired into a point-of-sale demonstration system which plays back canned demo tracks. You won’t be able to disconnect from the demo system and connect a synth to the back of the portable speakers on display. Thus, you should audition as many speakers as possible with the canned tracks and try to find the one with the best overall reproduction without “boxiness” and weak low end.
I tried out portable speakers in-store rather obsessively and exhaustively. I eventually settled on the JBL Charge 2 Bluetooth speaker. The JBL Charge 2 has reasonably flat response and good low end without the boxiness of many small speakers (such as the higher priced Jambox Mini). The Charge 2 is a little bit chunky weighing about 0.5 pounds. It specs out pretty well: 2×7.5 Watts and 75Hz – 20kHz frequency response. Two passive radiators provide solid bottom end; bass notes are distinct with recognizable pitch.
Sonically, I’m quite happy with the TRITON Taktile and JBL Charge 2 combination. The JBL handles high energy sounds like organ and French horn without distortion and flappy speakers. The headphone output from the TT is a little too low, however, and I must turn the volume all the way up on the JBL in order to get to rehearsal-level volume. Our church group rehearsals are “unplugged” (except for me, of course), so I don’t anticipate any problems on the job. However, I’m considering the addition of a battery-powered gain stage between the TT and the JBL. The following candidates for gain stage look viable:
- Boostaroo R234 Revolution Headphone Amplifier
- Rolls MX56C Minimix A/V Battery Powered Mixer
- MCM Custom Audio Compact Headphone Amplifier
The Rolls MX56C is attractive because, hey, who couldn’t use a battery powered utility mixer for other production applications? The MCM headphone amplifier has a Micro USB-B power input in addition to a 9V barrel connector. The MCM can be powered from a USB-A port just like the one on the Incase power brick.
Potentially, a fourth alternative is a guitar boost pedal. The pedal solution is viable as long as the pedal is flat and does not color the sound of the acoustic voices. I tried a Danelectro D-2 FAB Overdrive pedal with the jazz/pop voices and the overdrive does a great job of dirtying up the voices while adding gain. The TT voices are exceptionally clean and the added grit on electric pianos and guitars is especially welcome. As Moe the Bartender would say, “He ain’t pretty no more.”
There are two other aspects of the JBL Charge 2 that are worth mentioning. First, the JBL is such a chunk because it incorporates a 6000 mAh Lithium-ion Polymer battery and a 2.0 Amp USB-A charging/power port. Originally, I intended to power the TT using the JBL Charge 2. Unfortunately, there is too much digital noise on the USB power line when the TT is connected and is drawing power. One can clearly hear undesirable synthesis artifacts and noise at a completely unacceptable level when the JBL both powers and amplifies the TT. Now, I run the TT on the Incase power brick separately. I am thinking that the JBL could power the MCM headphone amplifier, hopefully without the digital noise.
Second off, the JBL is a Bluetooth speaker. (It works quite well in this capacity having tried the JBL with an iPad.) It seems like a no-brainer to send audio from the TT to the JBL over Bluetooth assuming that a Bluetooth audio transmitter is attached to the 3.5mm stereo output of the TT. This is a loser for live play, however. The transmitter must encode and compress the audio which imposes an unacceptable delay between playing a note and actually hearing the note through the JBL. I’ll stick to good ole latency-free audio cable.
The picture below shows the whole rig: the gray Incase power brick, the TRITON Taktile, and the JBL speaker resting on top of the TT. The TT does not have much clear room on top. Most of the top is taken by buttons, switches, sliders, pads, etc. The JBL’s perch is rather precarious. I would feel better having the JBL on the floor or a stable resting place nearby.
The entire rig fits into a Kaces 49-key gig bag and weighs 12 pounds. Finally, a self-powered rig that is as easy to handle and move as an acoustic guitar!