Headmaster 1.0 p 20
Special Combination Midi Out And Dc Power In
Even though the MIDI connector has 5 pins, only 3 of them are used. The other two are
undefined by the MIDI specification and unused by most MIDI gear. The RIVERA AMP
connector uses those two undefined pins as a DC Power Input. The Rivera
Knucklehead Amp, and all future Rivera MIDI enabled amps, provide DC power on
these pins.
This allows the Head Master to operate without a "wall-wart" style power supply.
Warning!
This connector should ONLY be used to connect the Head Master to a Rivera Amp.
There is no agreement among manufacturers on the use of these two pins. Some
manufacturers also use them to provide power, but it may be a different voltage or
polarity. If you plug a cable from the special RIVERA AMP connector into another
device, and that device ALSO uses these pins , BOTH devices may be damaged!
Midi Cables For The Rivera Amp Connector
Even though the MIDI specification only defines three pins, most manufacturers of MIDI
cables provide all five wires. This means that most normal MIDI cables will work
correctly in the special connector. However, if you find a MIDI cable that only has 3
wires, it will not work.
A Few Thoughts On Non-Standard Connectors
When we designed the Head Master, we faced a difficult decision. We wanted to supply
power to the pedal from the amplifier using one cable for both power and MIDI. We then
had two choices - Use a standard MIDI connector in a non-standard way, or use a non-
MIDI connector.
If we had used a non-MIDI connector, the unit would have been more foolproof. The
special combo MIDI and Power connector could ONLY be connected using the special
cable. There would be no way to hook it up incorrectly.
But then we thought about the poor guy on the road, far from a well-stocked music
store. If his special cable failed, he would be out of luck. We decided to use a standard
MIDI connector and cable in a non-standard way because it is very easy to find a
replacement.