Duophonic Keyboard module done!

dingebre · Posted: Tue Apr 17, 2012 7:53 pm Post subject: Duophonic Keyboard module done!

For me, this is the icing on the cake. The first module I built when I first met Nyle and started my project in the mid 1970s was the keyboard. It's somehow fitting I think that the Duophonic Keyboard is the last module for my Synthasystem.

There are pictures on the blog, here: http://analoguerealities.blogspot.com/

I decided on using COTO 9000 series, high sensitivity coil, reed relays to mimic the old Pratt-Read buss keybeds. The high sensitivity coil only draws 5 mA at 5 volts, just right for the Doepfer MTC 64 MIDI to TTL unit. Basically, the MTC 64 takes a note on/off and generates a unique TTL level voltage for that key, and that key alone. So, you turn a MIDI keyboard into a device which can control 64 other things with a single key press. For this module, the MTC 64 turns the relay matrix into a buss type keybed, perfect match.

The blog has more on the features, etc. Let me know if anyone has questions.

Here are a couple of photos.

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Description:

This is one of two relay PCBs. I had to split them into two due to the size of the relays.

Filesize:

1.24 MB

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729 Time(s)

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Description:

This is a side view of the module. You can see teh MIDI cables going into the MTC64, the two relay PCBs, and the Duophonic PCB on the bottom. To do over, I would flip the Duophonic PCB 180 degrees and maybe put it on top. I think I will rotate the trimmer

Filesize:

1.13 MB

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737 Time(s)

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Description:

This is the front panel. The Scale and Tune set the keyboard V/Oct and overall tuning (like the frequency knob on a VCO). The Range shifts the tuning by 1 octave per click. The Protamento adds glide between keys, a constant rate. The pitch bend bends the

Filesize:

1.06 MB

Viewed:

707 Time(s)

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