Besides the mechanical size standard of Eurorack modules, there is also a power standard.
A Eurorack case usually provides two power rails:
• ±12 V –
the most important rail, used by almost all modules. This is a
practical compromise that supplies enough energy for most integrated
circuits while providing sufficient headroom for classic audio and CV
signals.
• +5 V – mainly intended for digital modules. This
rail is less commonly used today, because most modern digital chips run
on 3.3 V or less, and most designers include onboard voltage regulators
to generate the required voltage locally.
There are two standard sizes:
• 10-pin – provides only ±12 V and ground.
• 16-pin – adds +5 V, as well as bus connections for CV and Gate signals.
The red (or otherwise marked) edge of the ribbon cable indicates the –12 V
side. On most designs, this is located at the bottom of the connector
(and should be clearly marked on the PCB if it’s different). This
becomes especially important if the IDC socket is replaced with a 0.1″
(2.54 mm) pin header to save space or cost.
Warning!
Do not plug in the cable incorrectly!
This can destroy your module.
Euroack Power
Besides the mechanical size standard of Eurorack modules, there is also a power standard.
A Eurorack case usually provides two power rails:
• ±12 V –
the most important rail, used by almost all modules. This is a
practical compromise that supplies enough energy for most integrated
circuits while providing sufficient headroom for classic audio and CV
signals.
• +5 V – mainly intended for digital modules. This
rail is less commonly used today, because most modern digital chips run
on 3.3 V or less, and most designers include onboard voltage regulators
to generate the required voltage locally.
Power is delivered via an IDC ribbon cable connector. There are two standard sizes:
• 10-pin – provides only ±12 V and ground.
• 16-pin – adds +5 V, as well as bus connections for CV and Gate signals.
The red (or otherwise marked) edge of the ribbon cable indicates the –12 V
side. On most designs, this is located at the bottom of the connector
(and should be clearly marked on the PCB if it’s different). This
becomes especially important if the IDC socket is replaced with a 0.1″
(2.54 mm) pin header to save space or cost.
These guides are part of our effort to share practical knowledge about DIY synth building,
tools, and Eurorack standards. We want them to be as clear and useful as possible, and we
know there’s always room for improvement.
Your feedback matters
If you spot an error, think something could be explained better, or want to share your own DIY tips,
please let us know. You can reach us at
shop@exploding-shed.com
or through our
contact page
.
Synth DIY Guides
These guides are part of our effort to share practical knowledge about DIY synth building,
tools, and Eurorack standards. We want them to be as clear and useful as possible, and we
know there’s always room for improvement.
Your feedback matters
If you spot an error, think something could be explained better, or want to share your own DIY tips,
please let us know. You can reach us at
shop@exploding-shed.com
or through our
contact page
.
