diff --git a/tests/node_mux9.rs b/tests/node_mux9.rs
new file mode 100644
index 0000000..00486cf
--- /dev/null
+++ b/tests/node_mux9.rs
@@ -0,0 +1,169 @@
+// Copyright (c) 2021 Weird Constructor <weirdconstructor@gmail.com>
+// This file is a part of HexoDSP. Released under GPL-3.0-or-later.
+// See README.md and COPYING for details.
+
+mod common;
+use common::*;
+
+fn setup_mux9_slct(matrix: &mut Matrix) {
+    let amp  = NodeId::Amp(0);
+    let mux9 = NodeId::Mux9(0);
+    let out  = NodeId::Out(0);
+    matrix.place(0, 0, Cell::empty(amp)
+                       .out(None, None, amp.out("sig")));
+    matrix.place(0, 1, Cell::empty(mux9)
+                       .input(mux9.inp("slct"), None, None)
+                       .out(None, None, mux9.out("sig")));
+    matrix.place(0, 2, Cell::empty(out)
+                       .input(out.inp("ch1"), None, None));
+    for i in 1..=9 {
+        pset_n(matrix, mux9, &format!("in_{}", i), 0.01 * (i as f32));
+    }
+
+    matrix.sync().unwrap();
+}
+
+fn setup_mux9(matrix: &mut Matrix) {
+    let mux9 = NodeId::Mux9(0);
+    let out  = NodeId::Out(0);
+    matrix.place(0, 0, Cell::empty(mux9)
+                       .out(None, None, mux9.out("sig")));
+    matrix.place(0, 1, Cell::empty(out)
+                       .input(out.inp("ch1"), None, None));
+    for i in 1..=9 {
+        pset_n(matrix, mux9, &format!("in_{}", i), 0.01 * (i as f32));
+    }
+
+    matrix.sync().unwrap();
+}
+
+#[test]
+fn check_node_mux9_9() {
+    init_test!(matrix, node_exec, 3);
+    setup_mux9(matrix);
+
+    let mux9 = NodeId::Mux9(0);
+
+    pset_s(matrix, mux9, "in_cnt", 9.into());
+
+    let (out, _) = run_for_ms(node_exec, 1.0);
+    assert_float_eq!(out[0], 0.01);
+
+    for i in 2..=9 {
+        pset_n_wait(matrix, node_exec, mux9, "t_up", 0.0);
+        pset_n_wait(matrix, node_exec, mux9, "t_up", 1.0);
+        let (out, _) = run_for_ms(node_exec, 1.0);
+        assert_float_eq!(out[0], 0.01 * (i as f32));
+    }
+}
+
+#[test]
+fn check_node_mux9_limit() {
+    init_test!(matrix, node_exec, 3);
+    setup_mux9(matrix);
+
+    let mux9 = NodeId::Mux9(0);
+
+    pset_s(matrix, mux9, "in_cnt", 2.into());
+
+    let (out, _) = run_for_ms(node_exec, 1.0);
+    assert_float_eq!(out[0], 0.01);
+
+    for i in 2..=3 {
+        pset_n_wait(matrix, node_exec, mux9, "t_up", 0.0);
+        pset_n_wait(matrix, node_exec, mux9, "t_up", 1.0);
+        let (out, _) = run_for_ms(node_exec, 1.0);
+        assert_float_eq!(out[0], 0.01 * (i as f32));
+    }
+
+    for i in 1..=3 {
+        pset_n_wait(matrix, node_exec, mux9, "t_up", 0.0);
+        pset_n_wait(matrix, node_exec, mux9, "t_up", 1.0);
+        let (out, _) = run_for_ms(node_exec, 1.0);
+        assert_float_eq!(out[0], 0.01 * (i as f32));
+    }
+}
+
+#[test]
+fn check_node_mux9_reset() {
+    init_test!(matrix, node_exec, 3);
+    setup_mux9(matrix);
+
+    let mux9 = NodeId::Mux9(0);
+
+    pset_s(matrix, mux9, "in_cnt", 5.into());
+
+    let (out, _) = run_for_ms(node_exec, 1.0);
+    assert_float_eq!(out[0], 0.01);
+
+    for i in 2..=3 {
+        pset_n_wait(matrix, node_exec, mux9, "t_up", 0.0);
+        pset_n_wait(matrix, node_exec, mux9, "t_up", 1.0);
+        let (out, _) = run_for_ms(node_exec, 1.0);
+        assert_float_eq!(out[0], 0.01 * (i as f32));
+    }
+
+    pset_n_wait(matrix, node_exec, mux9, "t_rst", 1.0);
+    pset_n_wait(matrix, node_exec, mux9, "t_rst", 0.0);
+
+    for i in 1..=3 {
+        let (out, _) = run_for_ms(node_exec, 1.0);
+        assert_float_eq!(out[0], 0.01 * (i as f32));
+        pset_n_wait(matrix, node_exec, mux9, "t_up", 0.0);
+        pset_n_wait(matrix, node_exec, mux9, "t_up", 1.0);
+    }
+}
+
+#[test]
+fn check_node_mux9_slct() {
+    init_test!(matrix, node_exec, 3);
+    setup_mux9_slct(matrix);
+
+    let mux9 = NodeId::Mux9(0);
+    let amp  = NodeId::Amp(0);
+
+    pset_s(matrix, mux9, "in_cnt", 5.into());
+    pset_n_wait(matrix, node_exec, amp, "inp", 0.9);
+
+    let (out, _) = run_for_ms(node_exec, 1.0);
+    assert_float_eq!(out[0], 0.06);
+
+    pset_n_wait(matrix, node_exec, amp, "inp", 0.0);
+    let (out, _) = run_for_ms(node_exec, 1.0);
+    assert_float_eq!(out[0], 0.01);
+
+    pset_n(matrix, amp, "inp", 1.0);
+    let (out, _) = run_for_ms(node_exec, 20.0);
+    assert_decimated_feq!(out, 90, vec![
+        0.01,
+        0.02,
+        0.03,
+        0.04,
+        0.05,
+        0.06,
+        0.06,
+        0.06,
+        0.06,
+    ]);
+
+    pset_s(matrix, mux9, "in_cnt", 8.into());
+    pset_n_wait(matrix, node_exec, amp, "inp", 0.0);
+
+    pset_n(matrix, amp, "inp", 1.0);
+    let (out, _) = run_for_ms(node_exec, 20.0);
+    assert_decimated_feq!(out, 50, vec![
+        0.01,
+        0.02,
+        0.03,
+        0.04,
+        0.05,
+        0.06,
+        0.07,
+        0.08,
+        0.09,
+        0.09,
+        0.09,
+        0.09,
+        0.09,
+    ]);
+}