//
K4815
// Pattern Generator
13p
MIDI Implementation
In addition to analog interfaces available from the front panel, the K4815 fully supports MIDI and
provides a number of useful functions that are not available on the front panel. It also provides a
useful MIDI clock output which can be used as either a stand-alone MIDI clock generator, or as an
analog (5V) clock to MIDI converter.
It also provides clock input via MIDI clock, which can be used instead of the analog clock input.
Control change and note outputs are supported, as well as note and controller input for transposing
the pattern, using key trigger playback mode, and reversing the direction of playback.
MIDI Hardware Interface
On the back of the K4815 PCB is a 10 pin header labelled as MIDI/TEST. It contains MIDI TX and RX
signals, +5V output, as well as a test pin which places the machine in test mode when jumpered to
ground. You can access the MIDI signals via a compatible Kilpatrick Audio MIDI module, or by building
your own MIDI interface to attach to the 10 pin connector. Since power is supplied, you can use a
single cable to connect a simple MIDI interface, with no main power supply connection required. Note
that the signals on the MIDI header are 5V TTL signals and cannot be interfaced directly to MIDI
cables without some simple circuitry. Please see the Kilpatrick Audio website for free information
about building your own MIDI interface.
MIDI Clock Support
By sending MIDI clock to the machine while it is in external clock mode, it is possible to synchronize
the machine to an external MIDI sequencer or other clock source. The input is divided by the CLOCK
SPEED control just as with an analog clock input.
When running in any clock mode, MIDI clock is sent to the MIDI output. This means that the machine
can be used as a MIDI clock generator (internal clock), or an analog to MIDI clock converter.
MIDI Program Change
The 64 motion types can be selected by a MIDI program change command received by the machine.
Programs 1-64 correspond to the 64 patterns selectable by the MOTION TYPE control. Programs 65-
128 correspond to the same 64 patterns, except that keyboard trigger mode is enabled. Keyboard
trigger mode allows the playback of a motion to be started when a key is pressed, to use the K4815 as
a sort of auto-arpeggiator.
MIDI Note Support
When in CV/GATE output mode, MIDI notes corresponding to the ones being sent from the CV and gate
outputs will be sent. The note length and transposition are the same as the analog outputs.
Notes received by the machine from an external MIDI keyboard will transpose the currently playing
notes. Middle C is treated as the default transposition. Any notes higher or lower will shift the note
User Manual
Hardware Version D/E
Firmware Version 1.1x
February 16, 2011
© 2010 Kilpatrick Audio
