diff --git a/src/devices/cpu/es5510/es5510.h b/src/devices/cpu/es5510/es5510.h
index f64c810906a66..d1036c23de6f5 100644
--- a/src/devices/cpu/es5510/es5510.h
+++ b/src/devices/cpu/es5510/es5510.h
@@ -17,7 +17,6 @@ class es5510_device : public cpu_device {
 	// TODO : Not verified, Most of games are using 128KB DRAM.
 	static constexpr uint32_t DRAM_SIZE = (1<<20);
 	static constexpr uint32_t DRAM_MASK = (DRAM_SIZE-1);
-	static constexpr feature_type imperfect_features() { return feature::SOUND; }
 
 	es5510_device(const machine_config &mconfig, const char *tag, device_t *owner, uint32_t clock);
 
diff --git a/src/devices/sound/esqpump.h b/src/devices/sound/esqpump.h
index e6257c1c97776..4d6cc0dd02745 100644
--- a/src/devices/sound/esqpump.h
+++ b/src/devices/sound/esqpump.h
@@ -16,8 +16,6 @@
 class esq_5505_5510_pump_device : public device_t, public device_sound_interface
 {
 public:
-	static constexpr feature_type imperfect_features() { return feature::SOUND; }
-
 	esq_5505_5510_pump_device(const machine_config &mconfig, const char *tag, device_t *owner, uint32_t clock);
 
 	template <typename T> void set_esp(T &&tag) { m_esp.set_tag(std::forward<T>(tag)); }
diff --git a/src/mame/ensoniq/esq5505.cpp b/src/mame/ensoniq/esq5505.cpp
index 5816ad04715d8..71a2246909dcb 100644
--- a/src/mame/ensoniq/esq5505.cpp
+++ b/src/mame/ensoniq/esq5505.cpp
@@ -1242,13 +1242,13 @@ void esq5505_state::init_denib()
 } // Anonymous namespace
 
 
-CONS( 1988, eps,    0,   0, eps,   vfx, esq5505_state, init_eps,    "Ensoniq", "EPS",             MACHINE_NOT_WORKING )  // custom VFD: one alphanumeric 22-char row, one graphics-capable row (alpha row can also do bar graphs)
-CONS( 1989, vfx,    0,   0, vfx,   vfx, esq5505_state, init_denib,  "Ensoniq", "VFX",             MACHINE_NOT_WORKING )  // 2x40 VFD
-CONS( 1989, vfxsd,  0,   0, vfxsd, vfx, esq5505_state, init_denib,  "Ensoniq", "VFX-SD",          MACHINE_NOT_WORKING )  // 2x40 VFD
-CONS( 1990, eps16p, eps, 0, eps,   vfx, esq5505_state, init_eps,    "Ensoniq", "EPS-16 Plus",     MACHINE_NOT_WORKING )  // custom VFD: one alphanumeric 22-char row, one graphics-capable row (alpha row can also do bar graphs)
-CONS( 1990, sd1,    0,   0, sd1,   vfx, esq5505_state, init_denib,  "Ensoniq", "SD-1 (21 voice)", MACHINE_NOT_WORKING )  // 2x40 VFD
-CONS( 1990, sq1,    0,   0, sq1,   sq1, esq5505_state, init_sq1,    "Ensoniq", "SQ-1",            MACHINE_NOT_WORKING )  // 2x16 LCD
-CONS( 1990, sqrack, sq1, 0, sq1,   sq1, esq5505_state, init_sq1,    "Ensoniq", "SQ-Rack",         MACHINE_NOT_WORKING )  // 2x16 LCD
-CONS( 1991, sq2,    0,   0, ks32,  sq1, esq5505_state, init_sq1,    "Ensoniq", "SQ-2",            MACHINE_NOT_WORKING )  // 2x16 LCD
-CONS( 1991, sd132,  sd1, 0, sd132, vfx, esq5505_state, init_denib,  "Ensoniq", "SD-1 (32 voice)", MACHINE_NOT_WORKING )  // 2x40 VFD
-CONS( 1992, ks32,   sq2, 0, ks32,  sq1, esq5505_state, init_sq1,    "Ensoniq", "KS-32",           MACHINE_NOT_WORKING)                       // 2x16 LCD
+CONS( 1988, eps,    0,     0, eps,   vfx, esq5505_state, init_eps,    "Ensoniq", "EPS",             MACHINE_NOT_WORKING )       // custom VFD: one alphanumeric 22-char row, one graphics-capable row (alpha row can also do bar graphs)
+CONS( 1989, vfx,    0,     0, vfx,   vfx, esq5505_state, init_denib,  "Ensoniq", "VFX",             MACHINE_IMPERFECT_TIMING )  // 2x40 VFD
+CONS( 1989, vfxsd,  0,     0, vfxsd, vfx, esq5505_state, init_denib,  "Ensoniq", "VFX-SD",          MACHINE_IMPERFECT_TIMING )  // 2x40 VFD
+CONS( 1990, eps16p, eps,   0, eps,   vfx, esq5505_state, init_eps,    "Ensoniq", "EPS-16 Plus",     MACHINE_NOT_WORKING )       // custom VFD: one alphanumeric 22-char row, one graphics-capable row (alpha row can also do bar graphs)
+CONS( 1990, sd1,    sd132, 0, sd1,   vfx, esq5505_state, init_denib,  "Ensoniq", "SD-1 (21 voice)", MACHINE_IMPERFECT_TIMING )  // 2x40 VFD
+CONS( 1990, sq1,    0,     0, sq1,   sq1, esq5505_state, init_sq1,    "Ensoniq", "SQ-1",            MACHINE_NOT_WORKING )       // 2x16 LCD
+CONS( 1990, sqrack, sq1,   0, sq1,   sq1, esq5505_state, init_sq1,    "Ensoniq", "SQ-Rack",         MACHINE_NOT_WORKING )       // 2x16 LCD
+CONS( 1991, sq2,    0,     0, ks32,  sq1, esq5505_state, init_sq1,    "Ensoniq", "SQ-2",            MACHINE_NOT_WORKING )       // 2x16 LCD
+CONS( 1991, sd132,  0,     0, sd132, vfx, esq5505_state, init_denib,  "Ensoniq", "SD-1 (32 voice)", 0 )                         // 2x40 VFD
+CONS( 1992, ks32,   sq2,   0, ks32,  sq1, esq5505_state, init_sq1,    "Ensoniq", "KS-32",           MACHINE_NOT_WORKING)        // 2x16 LCD