diff --git a/gtk2_ardour/ardour_knob.cc b/gtk2_ardour/ardour_knob.cc
index 8cea0f4a4d..1bb3671578 100644
--- a/gtk2_ardour/ardour_knob.cc
+++ b/gtk2_ardour/ardour_knob.cc
@@ -33,6 +33,7 @@
 #include "gtkmm2ext/gui_thread.h"
 #include "gtkmm2ext/keyboard.h"
 
+#include "ardour/automation_control.h"
 #include "ardour/rc_configuration.h" // for widget prelight preference
 
 #include "ardour_knob.h"
@@ -69,7 +70,8 @@ ArdourKnob::ArdourKnob (Element e, Flags flags)
 	UIConfiguration::instance().ColorsChanged.connect (sigc::mem_fun (*this, &ArdourKnob::color_handler));
 
 	// watch automation :(
-	Timers::rapid_connect (sigc::mem_fun (*this, &ArdourKnob::controllable_changed));
+	// TODO only use for GainAutomation
+	Timers::rapid_connect (sigc::bind (sigc::mem_fun (*this, &ArdourKnob::controllable_changed), false));
 }
 
 ArdourKnob::~ArdourKnob()
@@ -460,7 +462,7 @@ ArdourKnob::set_controllable (boost::shared_ptr<Controllable> c)
 
 	binding_proxy.set_controllable (c);
 
-	c->Changed.connect (watch_connection, invalidator(*this), boost::bind (&ArdourKnob::controllable_changed, this), gui_context());
+	c->Changed.connect (watch_connection, invalidator(*this), boost::bind (&ArdourKnob::controllable_changed, this, false), gui_context());
 
 	_normal = c->internal_to_interface(c->normal());
 
@@ -468,7 +470,7 @@ ArdourKnob::set_controllable (boost::shared_ptr<Controllable> c)
 }
 
 void
-ArdourKnob::controllable_changed ()
+ArdourKnob::controllable_changed (bool force_update)
 {
 	boost::shared_ptr<PBD::Controllable> c = binding_proxy.get_controllable();
 	if (!c) return;
@@ -476,13 +478,19 @@ ArdourKnob::controllable_changed ()
 	float val = c->get_interface();
 	val = min( max(0.0f, val), 1.0f); // clamp
 
-	if (val == _val) {
+	if (val == _val && !force_update) {
 		return;
 	}
 
 	_val = val;
 	if (!_tooltip_prefix.empty()) {
-		_tooltip.set_tip (_tooltip_prefix + c->get_user_string());
+		boost::shared_ptr<ARDOUR::AutomationControl> ac = boost::dynamic_pointer_cast<ARDOUR::AutomationControl> (c);
+		if (_printer && ac) {
+
+			_tooltip.set_tip (_tooltip_prefix + _printer->value_as_string (ac));
+		} else {
+			_tooltip.set_tip (_tooltip_prefix + c->get_user_string());
+		}
 	}
 	set_dirty();
 }
diff --git a/gtk2_ardour/ardour_knob.h b/gtk2_ardour/ardour_knob.h
index d9a9c94209..ede200f4b1 100644
--- a/gtk2_ardour/ardour_knob.h
+++ b/gtk2_ardour/ardour_knob.h
@@ -25,6 +25,8 @@
 #include <gtkmm/action.h>
 
 #include "pbd/signals.h"
+#include "ardour/automatable.h"
+
 #include "gtkmm2ext/binding_proxy.h"
 #include "gtkmm2ext/activatable.h"
 #include "gtkmm2ext/cairo_widget.h"
@@ -74,7 +76,7 @@ public:
 	void add_elements (Element);
 	static Element default_elements;
 
-	void set_tooltip_prefix (std::string pfx) { _tooltip_prefix = pfx; }
+	void set_tooltip_prefix (std::string pfx) { _tooltip_prefix = pfx; controllable_changed (true); }
 
 	boost::shared_ptr<PBD::Controllable> get_controllable() { return binding_proxy.get_controllable(); }
  	void set_controllable (boost::shared_ptr<PBD::Controllable> c);
@@ -84,6 +86,8 @@ public:
 	bool on_scroll_event (GdkEventScroll* ev);
 	bool on_motion_notify_event (GdkEventMotion *ev) ;
 
+	void set_printer (boost::shared_ptr<ARDOUR::Automatable> p) { _printer = p; controllable_changed (true); }
+
 	void color_handler ();
 
   protected:
@@ -97,14 +101,14 @@ public:
 	bool on_focus_in_event (GdkEventFocus*);
 	bool on_focus_out_event (GdkEventFocus*);
 
-	void controllable_changed ();
+	void controllable_changed (bool force_update = false);
 	PBD::ScopedConnection watch_connection;
 
 
   private:
-	Element                     _elements;
-
-	BindingProxy                binding_proxy;
+	Element _elements;
+	BindingProxy binding_proxy;
+	boost::shared_ptr<ARDOUR::Automatable> _printer;
 
 	bool _hovering;
 	float _grabbed_x;