Summary:
GroupDIY 51x Spec enhanced the API 500 Spec by adding 2 new power rails.
Radial Engineering has also enhanced the API 500 Spec by re-using three underused pins
The GroupDIY 51x pinout specs 7, 9 and 11 as NC and I was wondering whether it made sense for GroupDIY to adopt or acknowledge the Radial use?
About the Radial use:
Module fingers 7, 9, and 11 Radial describes as unused. API spec'd them as hot and cold -2dB inputs and a gain trim resistor. Still they are pretty much unused and GroupDIY 51x spec's them as NC.
Pin 7 and 9
Radial Engineering says in their “wh-userguide.pdf” available free online the following about the Omniport (http://www.radialeng.com/pdfs/wh-usersguide.pdf)
“OmniportTM is a special 1⁄4” TRS jack located on the rear panel that has been left ‘open’ to allow the module to perform a unique task. In other words, depending on the type of module, the manufacturer can assign the Omniport to perform a function that may be most appropriate. This could be a key input on a gate, a footswitch on a guitar effect or maybe an instrument input on a mic preamp.
The card-edge pins 7 and 9 (unused in the original spec) have been assigned to the OmniportTM TRS connector. The application here is only limited to one’s imagination as to the function that best relates to a given module. As the Omniport function is determined by the module, you will need to consult the module manufacturer’s specification for details on how it was designed to be used.”
This seems pretty innocuous, but does enable a number of uses. Here is a set of examples of uses Radial has made of the OmniPort, but many more purposes are possible (allowing for instance a module that outputs a stereo signal or two outputs without repurposing the input).
Module: Use made of OmniPort
PowerPre: Instrument input
JDV-Pre: Direct box output
PowerTube: Instrument input
PreComp: Send & receive insert
PreMax: Instrumentinput
X-Amp: Instrument input
PhazeQ: Balanced dry signal out
JDX: Direct box output
EXTC: Send & receive insert
Komit: Compressor side chain
Shuttle: Extra insert loop
Q3: Send & receive insert
Q4: UnbalancedI/O
TankDriver: Alternate reverb out
TossOver: Alternate 2-way output
SubMix: Mixer expansion bus
ChainDrive: Unbalancedinput
Pin 11
Radial Engineering says in their “wh-userguide.pdf” available free online the following about the Omniport
"Mixer Section
The mixer section in the Workhorse features an eight channel summing mixer with stereo outputs. It derives its signal via pin- 11 from the slot card-edge connector or from the D-sub summing mixer input connector. Each channel features an ON-OFF switch that enables you to select or mute the signal from the designated card slot. Individual channel gain controls are used to adjust the mix level while the pan control lets you position the signal across the stereo spectrum. To assign a channel to a left or right output, one simply hard-pans the module using the pan control. A channel-on LED lets you know when a channel is activated plus an overload peak indicator lets you monitor signal levels to ensure you are not overloading the summing mixer’s input."
also
"Radial Tech Note: Expansion Buss
The Radial ‘open source’ approach also enables the expansion buss to be interfaced with other manufacturer’s electronic equipment that is equipped with similar functionality such as products made by Rupert Neve DesignsTM. The expansion buss is essentially the inverting (virtual earth) input of an op-amp in the mixer section of the rack with a 4.75K Ohm resistor in series for unity gain connectivity. This can be used by an external device so long as it can operate into a 4.75K Ohm load. There is no DC blocking. This means that if there is any DC on the output of the external device, the clipping response of this stage will be non-symmetrical and headroom will be reduced."
It appears that pin 11's are all connected together as a single unbalanced virtual earth mix node with the input resistors spec'd above. They allow you to daisy chain that pin 11 bus (although they call it a Buss) between multiple (3) radial racks. it would not be hard to mod a 51x rack to connect pins 11 together on the backplane and achieve compatibility with an unbalanced TS connector.
Issues:
Should it be included? It might be a nice addition to GroupDIY 51x spec but maybe it is not needed. After all the Radial Spec is available and some folks have used it and it doesn't conflict with the 51x spec in any way. JLM makes some modules and some DIY PCB's that use the Radial Spec and the GroupDIY 51x spec for instance. It doesn't really restrict using pins 7 and 9 but it does really constrain 11 because there is going to be a mix bus on there (although the Workhorse does let you switch the pin 11 connection off). That constraint means it might be worth at least mentioning, if not adopting, how Radial uses Pin-11 so module makers could avoid accidental conflicts.
Are there any legal issues? Radial has published an Workhorse Open Source Document which originally they said was available freely by email, and it may be "free" but I never requested it because there is also an online form that requires a "click to agree" on various provisions about name use (you can't use Radial's name but radial can use yours and your picture etc... I suspect what happened was the lawyers got wind of the open source issue and over-reached). I wasn't comfortable with the provisions they really make very little sense. If GroupDIY (or whomever owns the GDIY 51x spec) wanted to include the Radial spec I think a simple note to Radial could sort out the issues, and I think Radial might view it as mutually beneficial without the bru-ha-ha (for instance as long as we called it a Radial Omniport pin, they might be happy), and nobody would have to give up their first born male child.
Any thoughts?
GroupDIY 51x Spec enhanced the API 500 Spec by adding 2 new power rails.
Radial Engineering has also enhanced the API 500 Spec by re-using three underused pins
The GroupDIY 51x pinout specs 7, 9 and 11 as NC and I was wondering whether it made sense for GroupDIY to adopt or acknowledge the Radial use?
About the Radial use:
Module fingers 7, 9, and 11 Radial describes as unused. API spec'd them as hot and cold -2dB inputs and a gain trim resistor. Still they are pretty much unused and GroupDIY 51x spec's them as NC.
Pin 7 and 9
Radial Engineering says in their “wh-userguide.pdf” available free online the following about the Omniport (http://www.radialeng.com/pdfs/wh-usersguide.pdf)
“OmniportTM is a special 1⁄4” TRS jack located on the rear panel that has been left ‘open’ to allow the module to perform a unique task. In other words, depending on the type of module, the manufacturer can assign the Omniport to perform a function that may be most appropriate. This could be a key input on a gate, a footswitch on a guitar effect or maybe an instrument input on a mic preamp.
The card-edge pins 7 and 9 (unused in the original spec) have been assigned to the OmniportTM TRS connector. The application here is only limited to one’s imagination as to the function that best relates to a given module. As the Omniport function is determined by the module, you will need to consult the module manufacturer’s specification for details on how it was designed to be used.”
This seems pretty innocuous, but does enable a number of uses. Here is a set of examples of uses Radial has made of the OmniPort, but many more purposes are possible (allowing for instance a module that outputs a stereo signal or two outputs without repurposing the input).
Module: Use made of OmniPort
PowerPre: Instrument input
JDV-Pre: Direct box output
PowerTube: Instrument input
PreComp: Send & receive insert
PreMax: Instrumentinput
X-Amp: Instrument input
PhazeQ: Balanced dry signal out
JDX: Direct box output
EXTC: Send & receive insert
Komit: Compressor side chain
Shuttle: Extra insert loop
Q3: Send & receive insert
Q4: UnbalancedI/O
TankDriver: Alternate reverb out
TossOver: Alternate 2-way output
SubMix: Mixer expansion bus
ChainDrive: Unbalancedinput
Pin 11
Radial Engineering says in their “wh-userguide.pdf” available free online the following about the Omniport
"Mixer Section
The mixer section in the Workhorse features an eight channel summing mixer with stereo outputs. It derives its signal via pin- 11 from the slot card-edge connector or from the D-sub summing mixer input connector. Each channel features an ON-OFF switch that enables you to select or mute the signal from the designated card slot. Individual channel gain controls are used to adjust the mix level while the pan control lets you position the signal across the stereo spectrum. To assign a channel to a left or right output, one simply hard-pans the module using the pan control. A channel-on LED lets you know when a channel is activated plus an overload peak indicator lets you monitor signal levels to ensure you are not overloading the summing mixer’s input."
also
"Radial Tech Note: Expansion Buss
The Radial ‘open source’ approach also enables the expansion buss to be interfaced with other manufacturer’s electronic equipment that is equipped with similar functionality such as products made by Rupert Neve DesignsTM. The expansion buss is essentially the inverting (virtual earth) input of an op-amp in the mixer section of the rack with a 4.75K Ohm resistor in series for unity gain connectivity. This can be used by an external device so long as it can operate into a 4.75K Ohm load. There is no DC blocking. This means that if there is any DC on the output of the external device, the clipping response of this stage will be non-symmetrical and headroom will be reduced."
It appears that pin 11's are all connected together as a single unbalanced virtual earth mix node with the input resistors spec'd above. They allow you to daisy chain that pin 11 bus (although they call it a Buss) between multiple (3) radial racks. it would not be hard to mod a 51x rack to connect pins 11 together on the backplane and achieve compatibility with an unbalanced TS connector.
Issues:
Should it be included? It might be a nice addition to GroupDIY 51x spec but maybe it is not needed. After all the Radial Spec is available and some folks have used it and it doesn't conflict with the 51x spec in any way. JLM makes some modules and some DIY PCB's that use the Radial Spec and the GroupDIY 51x spec for instance. It doesn't really restrict using pins 7 and 9 but it does really constrain 11 because there is going to be a mix bus on there (although the Workhorse does let you switch the pin 11 connection off). That constraint means it might be worth at least mentioning, if not adopting, how Radial uses Pin-11 so module makers could avoid accidental conflicts.
Are there any legal issues? Radial has published an Workhorse Open Source Document which originally they said was available freely by email, and it may be "free" but I never requested it because there is also an online form that requires a "click to agree" on various provisions about name use (you can't use Radial's name but radial can use yours and your picture etc... I suspect what happened was the lawyers got wind of the open source issue and over-reached). I wasn't comfortable with the provisions they really make very little sense. If GroupDIY (or whomever owns the GDIY 51x spec) wanted to include the Radial spec I think a simple note to Radial could sort out the issues, and I think Radial might view it as mutually beneficial without the bru-ha-ha (for instance as long as we called it a Radial Omniport pin, they might be happy), and nobody would have to give up their first born male child.
Any thoughts?
