Philip Rees Midi Thru Info

V3 MIDI THRU UNITClassic MIDI ‘splitter’

The highly suc-cessful V3 is ahandy one-into-three MIDI Thruunit, which youcan use to con-vert one MIDIout into threebuffered parallelouts. The V3 isvery compact -just 58mm x69mm x 23mm.

Power optionsYou can use a PP3 (6F22) battery to poweryour V3 - the battery will give a very longlife (usually a year or more in normal use).When you leave the IN socket uncon-nected, or your MIDI master device isquiescent or switched off, no battery poweris consumed.

You can use and external 6Vdc to 9Vdcsupply to power your V3 - you’ll have tomake connection via a PP3 type snap(press stud) connector with the negativevoltage on the male stud. The currentdemand is just 10mA maximum.

V4 MIDI THRU UNITThe V4 is ahandy one-into-four Thruunit and ithas the samecompactdimensionsas the V3.

Powered from the lineThe power for the V4 buffer circuit isderived from the MIDI connections at itsMIDI In socket. This configuration makesassumptions about the master MIDI device,so compatibilty problems can occur;problems are however rare.

The MIDIIn andpowercontrolcircuit ofthe V4 isdesignedfor bestpossible

compatibility and resistance to damage. Itwill work perfectly when driven by the vastmajority of MIDI master devices.

When an incompatible driver is found, it isnearly always easy to rearrange the systemto avoid the problem, as in the examplewhich follows. In the example below theMIDI Thru of the Synth Expander is chosento drivethe V4instead ofthe in-compat-ible MIDIoutput ofSynth 1.

V8 MIDI THRU UNITTwo output banksThis Thrubox haseight Thruoutputs.They arearrangedas twobanks offour. It hastwo MIDIinput ports,marked ‘A’and ‘B’.

There is an INPUT SELECT slide switch foreach output bank. Each switch has threepositions: position ‘A’ selects MIDI IN A,position ‘B’ selects MIDI IN B, while position‘0’ means no MIDI signal for that bank.

There are lamps that indicate when MIDI datais being received at each of the MIDI inputs.A POWER lamp is also fitted, to showwhen proper dc power is being supplied.

External power requiredThe V8 does not incorporate its own powersupply, so it requires to be connected to anexternal DC power source. An ordinarymains adaptor (regulated or unregulated) ofbetween nine and twelve volts will do fine.The current requirement is just 30mA.

Power connection is made via a 3.5mmjack socket, with the tip positive.

The dimensions of the V8 MIDI Thru Unitare 109mm x 109mm x 40mm.

V10 MIDI THRU UNITThe bigbrightMIDI star

The V10 is aone-into-tenMIDI Thrubox, which willconvert oneMIDI out into ten buffered parallel outs. Itwill provide your MIDI master device withThru outputs to drive up to ten slavedevices in a ‘star’ network.

Mains-poweredThe mains power supply of the V10 MIDIThru Unit is built-in, so no external adaptoris required. The mains lead is permanentlyfitted, so it won’t get lost. It is supplied witha mains plug fitted.

There is a POWER indicator lamp. Thedimensions are surprisingly compact - just175mm x 40mm x 45mm.

W5 DUAL INPUTMIDI THRU UNITTwo inputs and five outputsThe W5 has five MIDI Thru outputs, andtwo MIDI inputs - with independent sourceselection for each output. The W5 isversatile and excellent value-for-money.

On one side of the W5 are the two inputsockets, and on the other side are the fiveThru outputs. On the front panel are the fivethree-position slider selectors, one for eachoutput. Each switch can independently linkthe corresponding output to either of theinputs or a centre ‘off’ position.

The case of the W5 is 109mm x 109mm x40mm. Even though it is so compact, themains supply of the W5 is built-in, so youwaont need an external adaptor. Theintegral mains lead comes with a plug. AnLED POWER indicator is provided.

Why you need a MIDI thru unitInterconnecting several items of MIDI gearcan be a frustrating business.

Some of your MIDI gadgets may lack theMIDI Thru sockets which are required forconnecting several devices together in a�chain�. Where MIDI thru ports are provided,the signal throughput may introduce �dutycycle� distortion or time delays - so �chain�performance may be unacceptable,particularly on �chains� of three or more.

The preferred alternative to the troublesome�chain� is the �star� network. The only snagis that for a �star� network you will needmore than the single MIDI Out, which is allthat may be available on your mastercontroller. You�ll need a MIDI thru box tosolve this problem by setting up a MIDI�star� system.

A MIDI network may be expanded via ahybrid combination of �star�, and �chain�.

Phil Rees Music Tech +44 (0)1903 691160 www.philrees.co.uk