503rd: Try iPhone/iPad/USB compatible tiac "IU2"

　The iPhone/iPad is the most active in the world of DTM in both soft and hardware.The other day, a new feature has appeared from the Tiac's TASCAM brand."IU2", which has a actual selling price of about 15,000 yen, is a compact product that can be used as an audio interface by connecting to a Dock connector and as a MIDI interface.It is an almighty interface that can be connected to the line input and output, guitar, microphone, and S/PDIF.In fact, I checked the usability and audio performance.

■ Compatible with iPhone/iPod touch

　First of all, look at the photos connected to IU2, iPad, IU2 and iPhone.If you look at this, you can imagine the size.110 x 110 x 20mm and 220g is quite compact.Also, as you can see from the connection part with the iPad and the iPhone, the major feature is that the iPad Camera Connection Kit can be directly connected without the need.

　As has been introduced several times, the iPad can be connected to the USB audio interface by via the iPad Camera Connection Kit.However, when iOS 3 to iOS 4, the power that can be supplied from the main unit has been restricted, so most audio interfaces cannot be used unless power supply from the outside in some way.。There is also a disadvantage that the iPad Camera Connection Kit is required, so it cannot be used on the iPhone.

　Meanwhile, the TASCAM IU2 that appeared this time can be used on iPad, iPhone, and iPod touch.It also seems to be a considerable power saving design, and can be operated by power supply from iPad and iPhone.Looking at the specifications, the power consumption is 2.5W.In addition, it is lightweight because there is no built -in battery.Well, just because it is a power saving design, even if you connect to the iPad or iPhone, no lamps are lighted, so there is a little lonely aspect, but this is inevitable.

　What is unique is the connection cable.Although it is directly attached to the IU2 itself, if the cover on the back of the main unit is removed, it can be stored here, so there is no need to worry about losing the cable when carrying it.However, the length of the cable is about 25cm.

■ Digital output is possible from iPad/iPhone

　Let's take a look at the input / output equipped by IU2 from here.First, from the audio output.Looking at the rear panel, the RCA Jack's analog line output is prepared in stereo, and on the left is the RCA jack and the S/PDIF coaxial output.The iPad and iPhone do not support multi -port output, so they are output from both sides.However, there is one big difference.The volume from the analog output terminal is adjusted with the LINE OUT knob in the top panel, while the S/PDIF output is the maximum volume regardless of the setting of this knob.In other words, there is no strange conversion on the IU2 side, and the output from the iPad/iPhone can be digitally output without deterioration.

　In addition, a headphone terminal with a stereo mini jack is also provided on the left side of the main unit.This also has the same sound as the line output and S/PDIF output as the previous line output, but the volume is independent of the line output, so that it can be set with PHONES knobs.

　There are also two mini jacks to the left of the headphone output, but this is MIDI IN and MIDI OUT, and by using the attached cable, connecting to the external MIDI keyboard or MIDI sound source module.You can.

　Of course, this is a COREMIDI compatible MIDI interface, so it can be used in various applications, including GarageBand.Earlier, I introduced MIDI interfaces such as LINE6's Midi Mobilizer II, Yamaha's IMX-1, and IK Multimedia's IRig Midi, but this plays the same role.I could use the common MIDI cable in these three devices, so I thought that the same cable could be used with this IU2, but it wasn't.Because the plug used in Midi Mobilizer II etc. is 2.5mm diameter, IU2 is 3.Because it was a 5mm diameter.As a user, it would be nice if the standards in this area were unified, but it would be inevitable.

　Next is input.Looking at the front panel, there are three standard jacks here.The leftmost is the guitar, L and R, but the connection where you connect will be switched by the switch on the bottom panel, so let's look at these switches.

　First of all, if you look at Input R, it is a switch between MIC and LINE, so if you set it to LINE, the input of R will be a line.It is OK to connect a general unbalanced plug here, but this terminal is well -balanced, so if you connect a TRS phone, you can record it to a higher level.The input level can be adjusted with the input knob of the top panel, the line level when squeezed to the left, and the microphone level when turning to the right.If the level is overloaded at this time, the red clip lamp will light up.

　On the other hand, in the case of MIC, it is a microphone input, and it is still possible to connect with a TRS phone, but IU2 comes with two adaptors for converting TRS phones and XLR.If you use this, you can use the XLR terminal microphone.Moreover, if you turn on the Phantom switch, you can supply+48V phantom power, so you can connect and use a condenser.However, only the supply of this phantom power can be provided by the power supply only from the iPad/iPhone.This will be described later.

　Looking at the input L, there are also mic and LINEs like INPUT R, and the two are the same as INPUT R.However, INPUT L has another option of Guitar, and if you choose this, the input from the L terminal will be invalidated and the guitar input will be valid.This is a high impedance input, so it can be directly connected to a guitar or bass.However, in the case of a normal stereo setting, the guitar can only be heard from the left.Therefore, when the MONO switch on the bottom panel is turned on, the input becomes monaural and can be heard from the left and right.In such a case, input from Input R also becomes monaural at the same time.

■ Try iPad connection

　By the way, when you actually connect to the iPad, the input/output of the audio is automatically switched from the built -in to IU2, and the playback of the music transferred from iTunes is IU2 analog line output, headphone output, and S/PDIF.It comes out from the three output.On the other hand, when recording apps such as DAW, Portastudio, and Rectools such as GarageBand and MusicStudio are used, it is possible to record microphones and guitars connected to IU2.

　At this time, like a GarageBand guitar amplifier simulator, the application that can monitor the effect of the effect can be easily monitored, but even if the application does not have such a monitoring function, the IU2 has a function that can perform direct monitoring.It is done.It is a knob called Mon Mix in the top panel that controls it.If this knob is set to Computre on the left, only the sound sent from the iPad/iPhone will be output, but when turning to the right, enter the line input, microphone input, and guitar input.The signal is mixed, and when it is completely turned to the right, the sound from the iPad/iPhone disappears, and only the input is output as it is.

　In this case, the entered signal is directly monitored without going through the iPad/iPhone, making it possible to monitors with no latency.However, in the case of direct monitoring, the effect cannot be applied.In addition, the direct monitoring with Mon Mix is the line output and headphone output, and S/PDIF output is not eligible.

　MIDI can be used without any problems, but if you check the port using Art Technica's MIDITOOLBOX, you can see two terminals, IU2 port 1, IU2 port 2, both input and output.This was mentioned in the manual, but it seemed to be such a specification, choosing IU2 port 1 and ignoring IU2 port 2.There are two ports in terms of internal hardware, but it may be that the terminals are not attached.

■ PC connection with USB terminal

　By the way, there is one terminal that I did not touch so far.It is a USB terminal in the rear panel.This USB terminal can be used for various purposes.The first is for power supply.The power supply can be supplied from the AC adapter here using the USB cable, and the phantom power supply described above can be driven by this.In fact, if you turn on the rear panel's Phantom switch with this connected, the 48V indicator of the top panel will light red and you can move the condenser.Furthermore, in this state, power can be supplied to the connected iPad or iPhone to charge.This will allow you to use it without worrying about running out of battery.

　And this USB terminal has another big function.It can be connected to a PC and use IU2 as a PC audio interface and MIDI interface.To do so, it is necessary to switch the Host switch of the bottom panel from iOS Device to Computer and connect to a PC.By doing so, it can be used on both Windows and Mac.In addition, because it is compatible with so -called class compliance, it can be used immediately if you connect without installing the driver.However, the specifications are 16bit/44.Since it is an audio interface of 1kHz, 16bit/48kHz, there is no signal such as 24bit/96kHz.In addition, Windows is only compatible with MME drivers, not ASIO drivers.Nevertheless, when I installed ASIO4ALL of freeware, I was able to confirm that it could be used without any problems.

　So, I decided to test it using RMAA Pro how much the audio performance of this IU2 is.The loopback is performed by connecting the RCA analog line output to the front line input in the rear panel.16bit/44.The results of testing at 1kHz and 16bit/48kHz are as follows.

　As far as this is seen, it is certain that there is a slightly inferior side compared to ordinary audio interfaces.In particular, there are aspects in the frequency characteristics that low -range streets are still unusual.Nevertheless, there are no other interfaces that are so many functional, so it's reasonable in terms of price, so isn't this a compromise? Output in S/PDIF, external D/A.There is also a way to use it, and I would like to welcome the appearance of this compact and attractive equipment.