MIDI Merge & Thru

MIDIbox of the Week
1

Hi all

here is what i did these last days : a box, capable of merging two inputs (circuit of TK), and redistribute it through 4 thru outputs. In between, an out and an in, destinated to my MIDI Hardware Recorder of the moment : an MMT8.

So Merge in 1+2 =>merge out=>MMT8 in =>ECHO=>MMT8 out =>Thru in=>Thru Out 1+2+3+4

A jumper has been added to bypass the MMT8 if needed. It links the Merge out to the Thru in.

The schematic to create midi thru is very easy : the idea is to recopy the input. It uses Schmidt triggers. Find out more on

http://m.bareille.free.fr

As I wanted being nomad, I have added a battery supply. I just measured the current consumption  : 50 mA, so considering a 9V squared battery (500mAh), it can belong 10 hours, so approximatly 5 live gigs.

I also added bridge before the VR 7805 : so don’t have to worry if the supply is well connected or inverted between + and - pin.

I have put two DC in : one is for the Midibox, the other is a copy, in order to supply another machine. The diameters used are : 2.1 and 2.5, it covers every possibilities (my MMT8 is 2.5 for example) : it reduces the number of power supply that lay on the ground in your flat.

I don’t have a PCB maker, and the one of my School is out of order : I made it by hand and brain, on veroboard : there is only one wire under but several bridge upper. I was very long (approx 10h) to make.

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i discover yesterday that a router appli exists … i am a crap.

The hardest was to drill : i broke rear panel with circular holes, finally made a rectangular hole (with a saw, hardy).

the jumper is to make a direct link between merge out and thru in : can be replaced by a switch on the front panel.

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Doh! It’s still great work :slight_smile: Especially that you did it without TK’s app hehehe