diff --git a/libs/ardour/amp.cc b/libs/ardour/amp.cc
index 5294cdf377..4f6e8a5edb 100644
--- a/libs/ardour/amp.cc
+++ b/libs/ardour/amp.cc
@@ -40,8 +40,6 @@
 using namespace ARDOUR;
 using namespace PBD;
 
-#define GAIN_COEFF_DELTA (1e-5)
-
 Amp::Amp (Session& s, const std::string& name, std::shared_ptr<GainControl> gc, bool control_midi_also)
 	: Processor(s, "Amp", Temporal::TimeDomainProvider (Temporal::AudioTime))
 	, _apply_gain_automation(false)
diff --git a/libs/ardour/ardour/dB.h b/libs/ardour/ardour/dB.h
index 17eb798522..8e1f97c5ae 100644
--- a/libs/ardour/ardour/dB.h
+++ b/libs/ardour/ardour/dB.h
@@ -27,6 +27,7 @@
 #define GAIN_COEFF_ZERO 0.f
 #define GAIN_COEFF_SMALL 0.0000001f  //-140dB
 #define GAIN_COEFF_UNITY 1.f
+#define GAIN_COEFF_DELTA (1e-5) // -100dB
 
 static inline float dB_to_coefficient (float dB) {
 	return dB > -318.8f ? pow (10.0f, dB * 0.05f) : 0.0f;
diff --git a/libs/ardour/disk_reader.cc b/libs/ardour/disk_reader.cc
index 51b42c44dd..ecb3731262 100644
--- a/libs/ardour/disk_reader.cc
+++ b/libs/ardour/disk_reader.cc
@@ -1626,7 +1626,6 @@ DiskReader::dec_no_disk_output ()
 /* min gain difference for de-click and loop-fadess
  * (-60dB difference to target)
  */
-#define GAIN_COEFF_DELTA (1e-5)
 
 DiskReader::DeclickAmp::DeclickAmp (samplecnt_t sample_rate)
 {
diff --git a/libs/ardour/internal_send.cc b/libs/ardour/internal_send.cc
index 8f0c077ed8..9a0e78dd20 100644
--- a/libs/ardour/internal_send.cc
+++ b/libs/ardour/internal_send.cc
@@ -49,8 +49,6 @@ using namespace std;
 
 PBD::Signal<void(pframes_t)> InternalSend::CycleStart;
 
-#define GAIN_COEFF_DELTA (1e-5)
-
 InternalSend::InternalSend (Session&                      s,
                             std::shared_ptr<Pannable>   p,
                             std::shared_ptr<MuteMaster> mm,
diff --git a/libs/ardour/monitor_port.cc b/libs/ardour/monitor_port.cc
index 6dd6588155..d996a71eae 100644
--- a/libs/ardour/monitor_port.cc
+++ b/libs/ardour/monitor_port.cc
@@ -28,8 +28,6 @@
 #include "ardour/runtime_functions.h"
 #include "ardour/session.h"
 
-#define GAIN_COEFF_DELTA (1e-5)
-
 using namespace ARDOUR;
 using namespace std;