diff --git a/.appveyor.yml b/.appveyor.yml
index e5cbfa0f..aefd7714 100644
--- a/.appveyor.yml
+++ b/.appveyor.yml
@@ -15,7 +15,7 @@ install:
 
 build_script:
   - make
-  - zip -9 fluxengine.zip fluxengine.exe brother120tool.exe cwftoflux.exe fluxtovcd.exe
+  - zip -9 fluxengine.zip fluxengine.exe brother120tool.exe cwftoflux.exe fluxtovcd.exe fluxtoau.exe
 
 artifacts:
   - path: fluxengine.zip
diff --git a/lib/fluxmap.h b/lib/fluxmap.h
index a7a3f54a..14d467ed 100644
--- a/lib/fluxmap.h
+++ b/lib/fluxmap.h
@@ -21,6 +21,7 @@ public:
 
 public:
     nanoseconds_t duration() const { return _duration; }
+    unsigned ticks() const { return _ticks; }
     size_t bytes() const { return _bytes.size(); }
     const Bytes& rawBytes() const { return _bytes; }
 
diff --git a/mkninja.sh b/mkninja.sh
index 6081693d..0e1ed2d1 100644
--- a/mkninja.sh
+++ b/mkninja.sh
@@ -211,6 +211,14 @@ buildprogram fluxtovcd \
     libbackend.a \
     libfmt.a \
 
+buildlibrary libfluxtoau.a \
+    tools/fluxtoau.cc \
+
+buildprogram fluxtoau \
+    libfluxtoau.a \
+    libbackend.a \
+    libfmt.a \
+
 runtest dataspec-test       tests/dataspec.cc
 runtest flags-test          tests/flags.cc
 runtest fmmfm-test          tests/fmmfm.cc
diff --git a/tools/fluxtoau.cc b/tools/fluxtoau.cc
new file mode 100644
index 00000000..4e31b512
--- /dev/null
+++ b/tools/fluxtoau.cc
@@ -0,0 +1,98 @@
+#include "globals.h"
+#include "flags.h"
+#include "fluxmap.h"
+#include "sql.h"
+#include "bytes.h"
+#include "protocol.h"
+#include "dataspec.h"
+#include "fluxsource/fluxsource.h"
+#include "decoders/fluxmapreader.h"
+#include "fmt/format.h"
+#include <fstream>
+
+FlagGroup flags { &hardwareFluxSourceFlags };
+
+static DataSpecFlag source(
+    { "--source", "-s" },
+    "source for data",
+    ":d=0:t=0:s=0");
+
+static StringFlag output(
+    { "--output", "-o" },
+    "output AU file to write",
+    "output.au");
+
+static SettableFlag highDensityFlag(
+    { "--high-density", "--hd" },
+    "set the drive to high density mode");
+
+static SettableFlag withIndex(
+    { "--with-index" },
+    "place index markers in the right hand channel");
+
+int main(int argc, const char* argv[])
+{
+    flags.parseFlags(argc, argv);
+
+    const auto& locations = source.get().locations;
+    if (locations.size() != 1)
+        Error() << "the source dataspec must contain exactly one track (two sides count as two tracks)";
+    const auto& location = *(locations.begin());
+
+    std::cerr << "Reading source flux...\n";
+    setHardwareFluxSourceDensity(highDensityFlag);
+    std::shared_ptr<FluxSource> fluxsource = FluxSource::create(source);
+    const auto& fluxmap = fluxsource->readFlux(location.track, location.side);
+    unsigned totalTicks = fluxmap->ticks() + 2;
+    unsigned channels = withIndex ? 2 : 1;
+
+    std::cerr << "Writing output file...\n";
+    std::ofstream of(output, std::ios::out | std::ios::binary);
+    if (!of.is_open())
+        Error() << "cannot open output file";
+
+    /* Write header */
+
+    {
+        Bytes header;
+        header.resize(24);
+        ByteWriter bw(header);
+
+        bw.write_be32(0x2e736e64);
+        bw.write_be32(24);
+        bw.write_be32(totalTicks * channels);
+        bw.write_be32(2); /* 8-bit PCM */
+        bw.write_be32(TICK_FREQUENCY);
+        bw.write_be32(channels); /* channels */
+
+        of.write((const char*) header.cbegin(), header.size());
+    }
+
+    /* Write data */
+
+    {
+        Bytes data;
+        data.resize(totalTicks * channels);
+        memset(data.begin(), 0x80, data.size());
+
+        FluxmapReader fmr(*fluxmap);
+        unsigned timestamp = 0;
+        while (!fmr.eof())
+        {
+            unsigned ticks;
+            int op = fmr.readOpcode(ticks);
+            if (op == -1)
+                break;
+            timestamp += ticks;
+
+            if (op == F_OP_PULSE)
+                data[timestamp*channels + 0] = 0x7f;
+            if (withIndex && (op == F_OP_INDEX))
+                data[timestamp*channels + 1] = 0x7f;
+        }
+
+        of.write((const char*) data.cbegin(), data.size());
+    }
+
+    return 0;
+}