diff --git a/Detectors/TPC/calibration/include/TPCCalibration/SACDecoder.h b/Detectors/TPC/calibration/include/TPCCalibration/SACDecoder.h
index d16efc8995e8d..a57d9cafd10ff 100644
--- a/Detectors/TPC/calibration/include/TPCCalibration/SACDecoder.h
+++ b/Detectors/TPC/calibration/include/TPCCalibration/SACDecoder.h
@@ -233,6 +233,8 @@ class Decoder
 
   uint32_t mDebugLevel{0}; ///< Amount of debug information to print
 
+  uint32_t decodeTimeStamp(const char* data);
+
   /// \return status message: 1 = good, 0 = data length too short, -1 = decoding error
   int decodeChannels(DecodedDataFE& sacs, size_t& carry, int feid);
   void decode(int feid);
diff --git a/Detectors/TPC/calibration/src/SACDecoder.cxx b/Detectors/TPC/calibration/src/SACDecoder.cxx
index 49cfc81e067d5..24d64c872b787 100644
--- a/Detectors/TPC/calibration/src/SACDecoder.cxx
+++ b/Detectors/TPC/calibration/src/SACDecoder.cxx
@@ -60,7 +60,7 @@ bool Decoder::process(const char* data, size_t size)
 
   // check packet counters are increasing by one
   //
-  if (lastPacketInstance && (packetInstance != (lastPacketInstance + 1))) {
+  if (lastPacketInstance && (uint16_t(packetInstance) != uint16_t(lastPacketInstance + 1))) { // convert to uint16_t to respect size of sac.header.pktCount
     LOGP(error, "Packet for instance {} missing, last packet {}, this packet {}", instance, lastPacketInstance, packetInstance);
   }
 
@@ -137,6 +137,29 @@ int Decoder::decodeChannels(DecodedDataFE& sacs, size_t& carry, int feid)
   return 1;
 }
 
+uint32_t Decoder::decodeTimeStamp(const char* data)
+{
+  int carry = 0;
+  uint32_t value = 0;
+  for (int i = 0; i < 8; ++i) {
+    const auto c = data[carry];
+    uint32_t nibble = 0;
+    if ((c >= '0') && (c <= '9')) {
+      nibble = c - '0';
+    } else if ((c >= 'A') && (c <= 'F')) {
+      nibble = c - 'A' + 10;
+    } else {
+      LOGP(error, "unexpected '{}' in time stamp", data[carry]);
+      break;
+    }
+    value <<= 4;
+    value |= (nibble & 0xF);
+    ++carry;
+  }
+
+  return value;
+}
+
 void Decoder::decode(int feid)
 {
   const auto startTime = HighResClock::now();
@@ -157,7 +180,8 @@ void Decoder::decode(int feid)
       if ((carry == 0) && (data[0] == '\n') && (data[1] == 's')) {
         carry += 2;
       } else {
-        while (data[carry] != '\n') {
+        // while (data[carry] != '\n') {
+        while (data[carry] != 's') { // align to data after time stamp
           if (carry >= dataSize) {
             break;
           }
@@ -190,11 +214,7 @@ void Decoder::decode(int feid)
       const auto streamStart = carry;
       // time stamp comes after channel data
       ++carry;
-      std::string_view vd(&data[carry], 8);
-      std::stringstream str(vd.data());
-      str.flags(std::ios_base::hex);
-      uint32_t timeStamp;
-      str >> timeStamp;
+      uint32_t timeStamp = decodeTimeStamp(&data[carry]);
       decdata.timeStamp = timeStamp;
       decAdditional.timeStamp = timeStamp;
 
@@ -226,7 +246,8 @@ void Decoder::decode(int feid)
           auto& refCount = mTSCountFEs[feid].second;
           // NOTE: use (refTime > 1) instead of (refTime > 0), since in some cases the packet with TS 0 is missing
           if ((refCount == 0) && (refTime > 1)) {
-            LOGP(info, "Skipping initial data packet {} with time stamp {} for FE {}", mTSCountFEs[feid].first, timeStamp, feid);
+            LOGP(info, "Skipping initial data packet {} with time stamp {} for FE {}",
+                 mTSCountFEs[feid].first, timeStamp, feid);
           } else {
             if (refTime < firstRefTime) {
               // LOGP(info, "FE {}: {} < {}, adding {} DataPoint(s)", feid, refTime, firstRefTime, firstRefTime - refTime);
@@ -294,21 +315,25 @@ void Decoder::decode(int feid)
       ++carry;
     } else if (data[carry] >= 'a' && data[carry] <= 'z') {
       if (mReAlignType != ReAlignType::None) {
-        LOGP(error, "Skipping {} for FE {}, trying to re-align data stream", data[carry], feid);
+        LOGP(error, "Skipping {} for FE {}, trying to re-align data stream, time stamp packet count {}, ref count {}",
+             data[carry], feid, mTSCountFEs[feid].first, mTSCountFEs[feid].second);
         aligned = false;
         syncLost = true;
       } else {
-        LOGP(error, "Skipping {} for FE {}, might lead to decoding problems", data[carry], feid);
+        LOGP(error, "Skipping {} for FE {}, might lead to decoding problems, time stamp packet count {}, ref count {}",
+             data[carry], feid, mTSCountFEs[feid].first, mTSCountFEs[feid].second);
         ++carry;
       }
       decdata.reset();
     } else {
       if (mReAlignType != ReAlignType::None) {
-        LOGP(warn, "Can't interpret position for FE {}, {} / {}, {}, trying to re-align data stream\n", feid, carry, dataSize, std::string_view(&data[carry - 8], std::min(size_t(20), dataSize - 8 - carry)));
+        LOGP(warn, "Can't interpret position for FE {}, {} / {}, {}, trying to re-align data stream, time stamp packet count {}, ref count {}",
+             feid, carry, dataSize, std::string_view(&data[carry - 8], std::min(size_t(20), dataSize - 8 - carry)), mTSCountFEs[feid].first, mTSCountFEs[feid].second);
         aligned = false;
         syncLost = true;
       } else {
-        LOGP(error, "Can't interpret position for FE {}, {} / {}, {}, stopping decoding\n", feid, carry, dataSize, std::string_view(&data[carry - 8], std::min(size_t(20), dataSize - 8 - carry)));
+        LOGP(error, "Can't interpret position for FE {}, {} / {}, {}, stopping decoding, time stamp packet count {}, ref count {}",
+             feid, carry, dataSize, std::string_view(&data[carry - 8], std::min(size_t(20), dataSize - 8 - carry)), mTSCountFEs[feid].first, mTSCountFEs[feid].second);
         break;
       }
     }