diff --git a/src/sfizz/Config.h b/src/sfizz/Config.h
index b99eb5e2..52d26a31 100644
--- a/src/sfizz/Config.h
+++ b/src/sfizz/Config.h
@@ -24,8 +24,7 @@
 #pragma once
 
 namespace sfz {
-enum class Oversampling: int
-{
+enum Oversampling {
     x1 = 1,
     x2 = 2,
     x4 = 4,
diff --git a/src/sfizz/FilePool.cpp b/src/sfizz/FilePool.cpp
index 17e34f89..b6a5e46c 100644
--- a/src/sfizz/FilePool.cpp
+++ b/src/sfizz/FilePool.cpp
@@ -142,7 +142,7 @@ void sfz::FilePool::loadingThread() noexcept
                 if (sndFile.error() != 0)
                     continue;
 
-                DBG("Loading file for " << *promise->filename << " in the background");
+                DBG("Loading file for " << promise->filename << " in the background");
                 const uint32_t frames = sndFile.frames();
                 promise->fileData = readFromFile<float>(sndFile, frames);
                 promise->dataReady = true;
@@ -179,3 +179,19 @@ void sfz::FilePool::cleanupPromises() noexcept
         }
     }
 }
+
+
+void sfz::FilePool::setOversamplingFactor(sfz::Oversampling factor) noexcept
+{
+    this->oversamplingFactor = factor;
+}
+
+sfz::Oversampling sfz::FilePool::getOversamplingFactor() const noexcept
+{
+    return oversamplingFactor;
+}
+
+uint32_t sfz::FilePool::getPreloadSize() const noexcept
+{
+    return preloadSize;
+}
diff --git a/src/sfizz/FilePool.h b/src/sfizz/FilePool.h
index f5bd445c..08bae48a 100644
--- a/src/sfizz/FilePool.h
+++ b/src/sfizz/FilePool.h
@@ -133,6 +133,9 @@ public:
     void cleanupPromises() noexcept;
     FilePromisePtr getFilePromise(const std::string& filename) noexcept;
     void setPreloadSize(uint32_t preloadSize) noexcept;
+    uint32_t getPreloadSize() const noexcept;
+    void setOversamplingFactor(Oversampling factor) noexcept;
+    Oversampling getOversamplingFactor() const noexcept;
 private:
     fs::path rootDirectory;
 
diff --git a/src/sfizz/Region.cpp b/src/sfizz/Region.cpp
index 1e7a7758..2531ba81 100644
--- a/src/sfizz/Region.cpp
+++ b/src/sfizz/Region.cpp
@@ -644,9 +644,9 @@ float sfz::Region::getBaseGain() noexcept
     return normalizePercents(amplitude);
 }
 
-uint32_t sfz::Region::getOffset() noexcept
+uint32_t sfz::Region::getOffset(Oversampling factor) noexcept
 {
-    return offset + offsetDistribution(Random::randomGenerator);
+    return (offset + offsetDistribution(Random::randomGenerator)) * factor;
 }
 
 float sfz::Region::getDelay() noexcept
@@ -654,9 +654,19 @@ float sfz::Region::getDelay() noexcept
     return delay + delayDistribution(Random::randomGenerator);
 }
 
-uint32_t sfz::Region::trueSampleEnd() const noexcept
+uint32_t sfz::Region::trueSampleEnd(Oversampling factor) const noexcept
 {
-    return min(sampleEnd, loopRange.getEnd());
+    return min(sampleEnd, loopRange.getEnd()) * factor;
+}
+
+uint32_t sfz::Region::loopStart(Oversampling factor) const noexcept
+{
+    return loopRange.getStart() * factor;
+}
+
+uint32_t sfz::Region::loopEnd(Oversampling factor) const noexcept
+{
+    return loopRange.getEnd() * factor;
 }
 
 template<class T, class U>
@@ -757,13 +767,3 @@ float sfz::Region::velocityCurve(uint8_t velocity) const noexcept
 
     return gain;
 }
-
-void sfz::Region::setOversamplingFactor(sfz::Oversampling factor) noexcept
-{
-    oversamplingFactor = factor;
-}
-
-sfz::Oversampling sfz::Region::getOversamplingFactor() const noexcept
-{
-    return oversamplingFactor;
-}
diff --git a/src/sfizz/Region.h b/src/sfizz/Region.h
index 77c2a701..3692631b 100644
--- a/src/sfizz/Region.h
+++ b/src/sfizz/Region.h
@@ -201,7 +201,7 @@ struct Region {
      *
      * @return uint32_t
      */
-    uint32_t getOffset() noexcept;
+    uint32_t getOffset(Oversampling factor = x1) noexcept;
     /**
      * @brief Get the region delay in seconds
      *
@@ -214,14 +214,7 @@ struct Region {
      *
      * @return uint32_t
      */
-    uint32_t trueSampleEnd() const noexcept;
-    /**
-     * @brief Can the region use the preloaded data only to play its full range?
-     *
-     * @return true
-     * @return false
-     */
-    bool canUsePreloadedData() const noexcept;
+    uint32_t trueSampleEnd(Oversampling factor = x1) const noexcept;
     /**
      * @brief Parse a new opcode into the region to fill in the proper parameters.
      * This must be called multiple times for each opcode applying to this region.
@@ -232,21 +225,8 @@ struct Region {
      */
     bool parseOpcode(const Opcode& opcode);
 
-    /**
-     * @brief Set the oversampling factor to a new value. This will trigger updates of
-     * all the relevant values (sample ends, loop points, etc). It will also trigger
-     * preloading the file data again.
-     *
-     * @param factor
-     */
-    void setOversamplingFactor(Oversampling factor) noexcept;
-
-    /**
-     * @brief get the current oversampling factor
-     *
-     * @return Oversampling
-     */
-    Oversampling getOversamplingFactor() const noexcept;
+    uint32_t loopStart(Oversampling factor = x1) const noexcept;
+    uint32_t loopEnd(Oversampling factor = x1) const noexcept;
 
     // Sound source: sample playback
     std::string sample {}; // Sample
diff --git a/src/sfizz/Synth.cpp b/src/sfizz/Synth.cpp
index 8c06283e..a6fea684 100644
--- a/src/sfizz/Synth.cpp
+++ b/src/sfizz/Synth.cpp
@@ -550,10 +550,7 @@ void sfz::Synth::setOversamplingFactor(sfz::Oversampling factor) noexcept
     for (auto& voice: voices)
         voice->reset();
 
-    for (auto& region: regions) {
-        region->setOversamplingFactor(factor);
-    }
-
+    resources.filePool.setOversamplingFactor(factor);
     oversamplingFactor = factor;
 }
 
@@ -561,3 +558,18 @@ sfz::Oversampling sfz::Synth::getOversamplingFactor() const noexcept
 {
     return oversamplingFactor;
 }
+
+void sfz::Synth::setPreloadSize(uint32_t preloadSize) noexcept
+{
+    AtomicDisabler callbackDisabler{ canEnterCallback };
+    while (inCallback) {
+        std::this_thread::sleep_for(1ms);
+    }
+
+    resources.filePool.setPreloadSize(preloadSize);
+}
+
+uint32_t sfz::Synth::getPreloadSize() const noexcept
+{
+    return resources.filePool.getPreloadSize();
+}
diff --git a/src/sfizz/Synth.h b/src/sfizz/Synth.h
index 775963c7..410c14f4 100644
--- a/src/sfizz/Synth.h
+++ b/src/sfizz/Synth.h
@@ -296,6 +296,20 @@ public:
      * @return Oversampling
      */
     Oversampling getOversamplingFactor() const noexcept;
+
+    /**
+     * @brief Set the preloaded file size. This will disable the callback.
+     *
+     * @param factor
+     */
+    void setPreloadSize(uint32_t preloadSize) noexcept;
+
+    /**
+     * @brief get the current preloaded file size
+     *
+     * @return Oversampling
+     */
+    uint32_t getPreloadSize() const noexcept;
 protected:
     /**
      * @brief The parser callback; this is called by the parent object each time
diff --git a/src/sfizz/Voice.cpp b/src/sfizz/Voice.cpp
index 58a5700e..da2189ac 100644
--- a/src/sfizz/Voice.cpp
+++ b/src/sfizz/Voice.cpp
@@ -373,9 +373,9 @@ void sfz::Voice::fillWithData(AudioSpan<float> buffer) noexcept
     add<int>(sourcePosition, indices);
 
     //FIXME : all this casting is driving me crazy
-    const auto sampleEnd = min(static_cast<int>(region->trueSampleEnd()), static_cast<int>(source.getNumFrames())) - 1;
-    if (region->shouldLoop() && region->loopRange.getEnd() <= source.getNumFrames()) {
-        const auto offset = sampleEnd - static_cast<int>(region->loopRange.getStart());
+    const auto sampleEnd = min(static_cast<size_t>(region->trueSampleEnd(currentPromise->oversamplingFactor)), source.getNumFrames()) - 1;
+    if (region->shouldLoop() && region->loopEnd(currentPromise->oversamplingFactor) <= source.getNumFrames()) {
+        const auto offset = sampleEnd - static_cast<int>(region->loopStart(currentPromise->oversamplingFactor));
         for (auto* index = indices.begin(); index < indices.end(); ++index) {
             if (*index > sampleEnd) {
                 const auto remainingElements = static_cast<size_t>(std::distance(index, indices.end()));