midiplus miniEngine USB MIDI Sound Module

Works very well with the keyboard I have, works terribly with the midi guitar I have. Don't know why, I set the guitar with max sensitivity and a volume floor of 127 (max) but the device still barely registers that a signal is being sent...I have to pluck the hell out of the string. At least I have a fantastic little portable keyboard setup, in my case, an M-Audio KeyRig 49. The midiEngine even powers the keyboard (using USB)! All I have to do is plug an audio cable into the midiEngine and I'm golden. I have a feeling it'll work like that with any unpowered controller. Great little sound module.

This worked immediately with my m-Audio 32-key mini controller. The synth means I don't need a computer. I had the following issue: if you don't push the headphone plug in far enough it makes the sound very weak, and the reverb, when set to 0, makes the unit silent! The socket is a bit stiff, and I wonder if this caused some of the audio problems that others encountered. If I make sure the plug is pushed in all the way (mine makes a satisfying click), the sound in the headphones is quite loud enough, and the reverb is independent, as expected. This synth does just what I need, which is a small, portable synth/keyboard combination for learning. My Yamaha has better sound, but doesn't fit in a pocket. (I added a photo of my Yamaha PSR290 connected using the included MIDI-to-phone-plug cable.)

The midiplus arrived, and right from the start, I had some problems. However, I found a way around the problems and the final result is that it is working out very well.The first problem was that there was no midi output. I was deeply disappointed, but decided to try some different ways of testing out the module. It turns out that when I plugged in headphones to the unit, I had good synth operations. That is, I could control the volume and select different voices (patches) using the MG510 (Casio midi guitar) program functions. However, when I tried to connect the midiplus to the PA, the midi light went out. Next, I tried unplugging the MG510 from the PA and plugging the midiplus into the PA. The result was that it operated just fine as long as the MG510 was not plugged in.So, I went to Guitar center looking for some kind of isolation device like a 600 ohm to 600 ohm audio transformer, or an optical isolation unit. The clerk had no idea what I was asking for, but he did try. They have a multi-output 9volt pedal power supply that is supposed to eliminate ground loop problems, but that wouldn't do for isolating audio signals.So, it occurred to me that perhaps the solution would be to use a wireless guitar/mic system so that there was no physical connection of the midiplus to the PA. I had an older Sampson wireless system packed away. I dug it out, and hooked up the midiplus to it, and it works like a champ.The only other problem I had was that the midiplus has a button to change the reverb level of the audio output. I turned the reverb level down to zero, and found that when set to zero, there is no audio output at all regardless of the volume setting. However, it was not too severe of a problem because with the reverb level set very low, (10 out of 0-127) there was good audio output with very little reverb.I'm not sure if the problems I had will correlate to other applications, but for Casio MG510 players, this little midi module eliminates the need to carry around a keyboard synth to play some synth sounds. I found very little latency. One last item to note is that there does not seem to be any way to adjust the tuning of the Midiplus. However, that is a very minor detail for me.

I bought this when my ancient Proteus (outboard sound module) finally died, to use with a midi controller just to check notes and chords during sessions. I would certainly not play a show or record with this. The sounds are just OK, and definitely on the cheesy side.But even as a reference unit there are three issues which aren't quite deal-killers, but explain why it's so cheap.First, this unit is designed for headphones. The listing says "Headphone(LINE) OUT," but the signal is way too low for a standard line input. If you plan to use it this way, and can't adjust the trim on the input, you will probably need to add a headphone amp.Second, you have to manage the battery. It can't be run on straight DC. If you leave it plugged in at all times (my preference) the battery is constantly charging, and thus guaranteed to eventually fail. This means you should really unplug it and use the battery until it needs to be recharged. Great for portability, but a total drag when you want to just leave it on and ready.Third, it does some wacky stuff while powering on. Sometimes it comes on with a quick press of the power button. Other times it seems to require holding the button for a few seconds. Sometimes it enters what looks like a maintenance mode, but there's no mention of that in the documentation.Again, these aren't terrible problems. The device does work, and is certainly easy to use. But it's more like a musical toy than a serious studio device. Because it was cheap, I've decided to keep it. But I also expect to be shopping for a replacement sooner rather than later.