diff --git a/hardware/externalopl.rst b/hardware/externalopl.rst
new file mode 100644
index 0000000..bdbe363
--- /dev/null
+++ b/hardware/externalopl.rst
@@ -0,0 +1,16 @@
+External OPL audio
+==================
+
+The **YMOPL2Board** :ref:`sound card <settings/sound:Sound card #1-#4>` allows for a real Yamaha OPL2 (YM3812) chip to be connected to the emulated machine for authentic FM synthesis output.
+
+Usage
+-----
+
+1. Connect the `OPL2 Audio Board from Cheerful Electronic <https://www.cheerful.nl/OPL2_Audio_Board/>`_ to a `supported Arduino board <https://github.com/DhrBaksteen/ArduinoOPL2/wiki/Connecting-the-OPL2-Audio-Board>`_.
+2. Connect the Arduino board to the host system.
+3. Select the **YMOPL2Board (External Device)** sound card on the :ref:`emulated machine's configuration <settings/sound:Sound card #1-#4>`.
+4. Use the *Configure* button to select the Arduino's serial port.
+
+.. note::
+  * The **OPL3 Duo!** board is currently not supported.
+  * Regular **PCM/wave audio** still requires an emulated sound card to be configured. If the emulated sound card provides its own OPL, it can often be **muted** through a mixer utility within the machine.
diff --git a/index.rst b/index.rst
index e1f7d01..46bfe5c 100644
--- a/index.rst
+++ b/index.rst
@@ -50,6 +50,7 @@ Contents
    hardware/ideterqua
    hardware/network
    hardware/isabugger
+   hardware/externalopl
 
 .. toctree::
    :maxdepth: 1
diff --git a/settings/sound.rst b/settings/sound.rst
index 643b975..92474d8 100644
--- a/settings/sound.rst
+++ b/settings/sound.rst
@@ -16,6 +16,8 @@ The *Configure* button opens a new window with settings specific to the selected
 
 Emulation for the Yamaha OPL series of synthesizers (used by many of the emulated cards) is provided by a modified `Nuked OPL3 <https://github.com/nukeykt/Nuked-OPL3>`_ or `ymfm <https://github.com/aaronsgiles/ymfm>`_ library, per the :ref:`selection below <settings/sound:FM synth driver>`. MOS Technology 6581 SID emulation for the Innovation SSI-2001 and The Entertainer is provided by the reSIDfp component of the `libsidplayfp <https://github.com/libsidplayfp/libsidplayfp>`_ library. General Instrument AY-3-8913 emulation for the Mindscape Music Board is provided by the `Ayumi <http://sovietov.com/app/ayumi/ayumi.html>`_ library.
 
+The **YMOPL2Board** requires an external hardware device containing an OPL2 chip. See :doc:`../hardware/externalopl` for more information.
+
 MIDI Out Device
 ---------------