Updated Version announced Jul09!
The Touch Panel began life with investigation of articles in the 1970s Synapse Magaine
(A Touch Responsive Keyboard / Constructing a Programmer), but the module presented here bares little resemblance to the ideas discussed there. The initial prototype version (shown below) has now been updated with a Sequencing core to create one of the most unique and downright fun modules of the system. Note Oct09:
since the initial run of the v2 I have slightly changed the functioning during sequencing - now pressing a key will 'HOLD' on that step while the key is pressed instead of jumping and then continuing to step - this was deemed an improved function in use!
The four Keys
are shaped to provide a highly responsive tactile interface with each generating an independent Pressure CV output along with summed Common
outputs for overall Pressure and Gate. The module is generally considered monophonic, but the pressure outputs can be changed by touching more than one key.
The keys are also used to select the active stage (column A-D) of the three Preset Rows
. You can think of these as four-step touch-activated sequencer rows - at any time only one step is active, the one corresponding to the last key pressed. Each row has an independent CV output and a switch to select the output voltage range.
The major addition to this new version is the inclusion of Step Sequencing allowing the selected stage to be shifted Left or Right by an external clock signal. This can actually be clocked by any signal rising over 1v and the sequencing core can run right up into audio rates allowing the Preset Rows to act as suboscillators when clocked from a VCO.
For an overview of the various functions check out the YouTube video below.Note: these touch keys should not be confused with those on the Weevil range - they are totally different in response and method!Instruction Sheet (pdf)
Step Input Threshold:
c. 1v (passes through comparator)CV Outputs:
0 -> +10v (0v when no touch)Row Outputs:
independently selectable 1v / 5v / 10vGate Output:
0 -> +5v (0v when no touch, +5v on any key press)PCB trimmers:
Sensitivity (key pressure), Row Voltages x 3 (1v/5v/10v)
Added on Saturday 03 January, 2009.