diff --git a/radio/tests/interpolation/farrow/Makefile b/radio/tests/interpolation/farrow/Makefile
index d04d847..f6f4e0a 100644
--- a/radio/tests/interpolation/farrow/Makefile
+++ b/radio/tests/interpolation/farrow/Makefile
@@ -9,6 +9,8 @@ CXXFLAGS += -std=c++20
 CXXFLAGS += -Wno-volatile
 CXXFLAGS += -Wno-deprecated-declarations
 
+DEFINES_debug += -DTEST_DEBUG
+
 PWD := $(realpath .)
 CXX_SRCS += $(PWD)/main.cpp
 CXX_SRCS += $(PWD)/test.cpp
diff --git a/radio/tests/interpolation/farrow/test.cpp b/radio/tests/interpolation/farrow/test.cpp
index 0df7b2e..b335bc3 100644
--- a/radio/tests/interpolation/farrow/test.cpp
+++ b/radio/tests/interpolation/farrow/test.cpp
@@ -116,7 +116,9 @@ class TimingGeneratorGardner : public Interpolation::TimingGenerator
 		if (is_time)
 		{
 			// @1 x symbolrate
+#ifdef TEST_DEBUG
 			cout << "Vd = " << vd << ", omega = " << m_dOmega << ", mu = " << getMu() << endl;
+#endif
 			m_dOmega = LeadLagProcess(&loop_filter_str, &str_loopfilter_coeff, vd);
 		}
 		is_time = not is_time;
@@ -138,8 +140,13 @@ void test()
 
 	// Setup IQ data
 	WAVEHEADER header;
+#ifdef TEST_DEBUG
 	CVec iq_in = wavLoad("m2_12k_12k_i_q_short_2sps.wav", header);
 //	CVec iq_in = wavLoad("sine.wav", header);
+#else
+	CVec iq_in = wavLoad("m2_12k_12k_i_q_2sps.wav", header);
+#endif
+
 	CVec iq_out;
 	iq_out.reserve(8*iq_in.size());