Connections for LinnStrument and LinnStrument 128 are identical except LinnStrument 128 does not have the power input jack, which is not necessary because its power is supplied from the USB connection. In fact, few LinnStrument owners use the power jack.
(Not on LinnStrument 128): Standard round power connector, for use when not getting power from USB. Any DC power supply, center negative or center positive from 7.5 to 15 volts, at least 300 mA can be used. Or any AC supply with 9 to 15 volts, at least 300+ mA, can also be used.
Standard full-size MIDI IN and OUT jacks. Be sure MIDI I/O (in Global Settings) is set to MIDI JACKS. There's little need to connect MIDI IN unless you're using MIDI Sync or want custom MIDI control of the panel lights.
Full-size USB B (peripheral) jack. Use for 3.7 times faster MIDI speed than the MIDI jacks, and to provide power. Can be used for power with any standard USB power adaptor when using the MIDI jacks. LinnStrument can also be powered with any iPad with USB-C, or with an iPad or iPhone with lightning connector, though see below for power limitations from Lightning.
Tip: To protect the USB jack against damage from cable pulls, tie the USB cable around the nearest guitar strap button. This will act as a strain relief, a trick that guitarists have used for years. See near the end of this page for more info.
Stereo 1/4 inch jack for single or dual momentary (not latching) foot switch (not expression pedal). Functions of foot switches are assigned in GLOBAL SETTINGS. If using a single foot switch, only the Right Foot Switch setting is used. You can use either Normally Open or Normally Closed foot switches because the unpressed state is automatically sensed when power is connected. By default, the right foot switch (or a single foot switch) is assigned to Sustain Pedal and the left foot switch is assigned to Arpeggiator On/Off.
LinnStrument is a MIDI controller and doesn't generate its own sounds, so you'll need to connect it to a computer, iPad or hardware MIDI synth in order to generate sound.
The large LinnStrument is usually powered from its USB jack. LinnStrument requires at least 350 milliamperes of current. A computer's USB jack usually provides that but a USB hub--especially a USB hub without its own power supply-- often doesn't. If LinnStrument's lights ever flash unexpectedly, this means it's not getting enough current.
Important: if LinnStrument's lights ever flash unexpectedly, this means it's not getting enough power. If this unexpected flashing happens repeatedly, eventually this could cause LinnStrument to stop working, requiring a reload of the current software version to bring it back to life. So if you see this unexpected flashing, stop and change to a better source of power.
Connect a USB cable from LinnStrument your computer for both MIDI communication and power. A computer's USB jack usually provides 500 mA of current, which is adequate for LinnStrument. USB is better for MIDI data than the round MIDI jacks because it's 3.7 times faster.
Once connected, "LinnStrument MIDI" should appear in your computer. Be sure that Global Settings > Actions column > USB is selected. If you're using a USB hub and having any problems, try connecting directly to your computer. If your computer isn't recognizing LinnStrument, see the LinnStrument FAQ page, "Problems" tab, first FAQ.
Current iPads don't have an audio output jack, so you must use the USB-C or Lightning jack for power, MIDI input and audio output. I (Roger) use the following configuration in order to connect my iPad Pro (with USB-C) simulaneously to 1) power for both iPad and LinnStrument, 2) LinnStrument USB to iPad, and 3) quality stereo audio output from iPad:
1) Anker USB C Hub, 7-in-1 USB C Adapter, about $50 on Amazon
2) Apogee Jam+ USB Instrument Input and Stereo Output for iPad, $159 on Apple's site
There are other products that do the same thing.
Regarding power, an iPad with USB-C will power your LinnStrument fine.
If using an iPad or iPhone with Lightning connector, Lightning doesn't provide adequate power for LinnStument, so you'll need to enable LinnStrument's Low Power mode (in Global Settings, Power/MIDI column.) To start LinnStrument in Low Power mode, hold Octave/Transpose while connecting power.
Also, you'll need to use a Lightning-to-USB adapter. It's best to use Apple's adaptors because other third-party adaptors usually don't provide enough power for LinnStrument, even in Low Power mode. Apple has two such adapters:
1) Apple's $30 Lightning to USB Camera Adapter. Use this adapter if you wish to power LinnStrument from the iDevice's battery.
2) Apple's $40 Lightning to USB 3 Camera Adapter. This would seem to be the ideal adapter to power both your iDevice and LinnStrument because it has an additional Lightning port for connecting a USB power supply. However, this additional Lightning port only powers the iPad, not any devices connected to its USB jack like LinnStrument. Also, Apple appears to change the amount of power this adapter can supply to external devices (LinnStrument) with some iOS updates. As of March 2018, iOS supplied enough power for LinnStrument from my (Roger's) iPhone X but not from my 2016 iPad (not Pro) or my 2016 iPad Pro (large). So it seems to supply enough current from newest iDevices but not older ones but because of Apple's changes to these rules, you'll have to try it out to see if it works with your iDevice and iOS version.
Other options for powering LinnStrument are:
1)Use a USB Y-adapter cable that has 2 flat USB connectors at the computer/iPad end of the cable--one for data and another for power, thereby eliminating the need for the iDevice to supply power.
2) If you have the large LinnStrument model, connect the power input to a DC power supply.
You can also use LinnStrument's MIDI OUT to connect to a hardware MIDI synth or your computer's MIDI interface. In this case, you must power LinnStrument either by USB or (on the large LinnStrument model) by a power supply. By default, the MIDI I/O parameter (Global Settings, column 15) is set to USB, so you must select MIDI JACKS if you are using the MIDI jacks.
I (Roger) have tested the WIDI Master from CME-PRO and found it to be well-designed, fast, easy to use and low-cost at only $59. You simply connect its two little wireless plugs into LinnStrument's MIDI IN and OUT jacks, and it transmits and receives low-latency MIDI over Bluetooth to and from your computer or other Bluetooth device.
Interestingly, CME have figured out how to get the latency down to as low as 3 mS, which is quite an accomplishment. In my test playing 3-note chords and melody with 3D MPE expression, I didn't perceive any added latency or delays normally associated with Bluetooth.
Also, LinnStrument's software creator Geert Bevin has created a way to make your LinnStrument fully wireless by integrating a WIDI Master, an Anker PowerCore+ power source, and a custom 3D-printed holder.
You can connect either a single or dual momentary (not latching) foot pedal switch to LinnStrument's 1/4" Foot Switch jack. For example, any keyboard sustain pedal can be used. It can be a Normally Closed or Normally Open foot switch, because LinnStrument automatically senses which type is connected when you connect power. If you use a single foot switch, it should have a standard mono (tip-sleeve) 1/4" plug and only LinnStrument's Right Foot Switch assignment will work. If you use a dual foot switch, it should have a standard stereo (ring-tip-sleeve) 1/4" plug.
There are three dual foot switches we're aware of:
1) The StudioLogic VFP2/10B (normally open ) or VFP2/15B (normally closed), both of which work with LinnStrument. Be sure to get these model numbers with a single TRS stereo jack (works with LinnStrument) and not the models with two TS jacks, which won't work with LinnStrument.
2) Crumar Dual Footswitch, available in the U.S. at Sweetwater
3) Saturnworks Amp Switches. Select the "Momentary Double Switch Normally Open" option.
Unfortunately the classic USB jack was designed for stationary things like printers and modems, and not for music instruments. If you pull hard on your USB cable, this can damage LinnStrument's USB jack, requiring replacement of the main circuit board.
To avoid such damage, tie the USB cable around the nearest guitar strap button, similar to how guitarists commonly protect the guitar's output jack. This acts as a strain relief and protects the USB jack. This is especially important when playing LinnStrument in the standing position.
The Model 18825 Equipment Stand from German company K&M is a sturdy, steel-construction floor stand that works well with either LinnStrument or LinnStrument 128.