diff --git a/sdl2-hyper-sonic-drivers/src/HyperSonicDrivers/drivers/midi/IMidiChannelVoice.cpp b/sdl2-hyper-sonic-drivers/src/HyperSonicDrivers/drivers/midi/IMidiChannelVoice.cpp
new file mode 100644
index 00000000..bedfd4e3
--- /dev/null
+++ b/sdl2-hyper-sonic-drivers/src/HyperSonicDrivers/drivers/midi/IMidiChannelVoice.cpp
@@ -0,0 +1,21 @@
+#include <HyperSonicDrivers/drivers/midi/IMidiChannelVoice.hpp>
+#include <HyperSonicDrivers/drivers/midi/IMidiChannel.hpp>
+
+namespace HyperSonicDrivers::drivers::midi
+{
+    uint8_t IMidiChannelVoice::getChannelNum() const noexcept
+    {
+        return m_channel->channel;
+    }
+
+    void IMidiChannelVoice::setVolumes(const uint8_t volume) noexcept
+    {
+        m_volume = volume;
+        m_real_volume = calcVolume_();
+    }
+
+    uint8_t IMidiChannelVoice::calcVolume_() const noexcept
+    {
+        return  std::min<uint8_t>((static_cast<uint32_t>(m_volume) * m_channel->volume / 127), 127);
+    }
+}
diff --git a/sdl2-hyper-sonic-drivers/src/HyperSonicDrivers/drivers/midi/opl/OplChannel.cpp b/sdl2-hyper-sonic-drivers/src/HyperSonicDrivers/drivers/midi/opl/OplChannel.cpp
new file mode 100644
index 00000000..ba75b84d
--- /dev/null
+++ b/sdl2-hyper-sonic-drivers/src/HyperSonicDrivers/drivers/midi/opl/OplChannel.cpp
@@ -0,0 +1,6 @@
+#include <HyperSonicDrivers/drivers/midi/opl/OplChannel.hpp>
+
+namespace HyperSonicDrivers::drivers::midi::opl
+{
+
+}
diff --git a/sdl2-hyper-sonic-drivers/src/HyperSonicDrivers/drivers/midi/opl/OplChannel.hpp b/sdl2-hyper-sonic-drivers/src/HyperSonicDrivers/drivers/midi/opl/OplChannel.hpp
new file mode 100644
index 00000000..52c6e26d
--- /dev/null
+++ b/sdl2-hyper-sonic-drivers/src/HyperSonicDrivers/drivers/midi/opl/OplChannel.hpp
@@ -0,0 +1,12 @@
+#pragma once
+
+#include <HyperSonicDrivers/drivers/midi/IMidiChannel.hpp>
+
+namespace HyperSonicDrivers::drivers::midi::opl
+{
+    class OplChannel : public IMidiChannel
+    {
+    public:
+        OplChannel() = default;
+    };
+}