diff --git a/gtk2_ardour/midi_channel_selector.cc b/gtk2_ardour/midi_channel_selector.cc
index 327b9d74ae..6fba415389 100644
--- a/gtk2_ardour/midi_channel_selector.cc
+++ b/gtk2_ardour/midi_channel_selector.cc
@@ -1,11 +1,18 @@
 #include "midi_channel_selector.h"
+#include "gtkmm/separator.h"
+#include "i18n.h"
 #include <sstream>
 
 using namespace std;
 
-MidiChannelSelector::MidiChannelSelector() :
-	Gtk::Table(4,4,true)
-{
+MidiChannelSelector::MidiChannelSelector(int no_rows, int no_columns, int start_row, int start_column) :
+	Gtk::Table(no_rows, no_columns, true)
+{	
+	assert(no_rows >= 4);
+	assert(no_rows >= start_row + 4);
+	assert(no_columns >=4);
+	assert(no_columns >= start_column + 4);
+	
 	property_column_spacing() = 0;
 	property_row_spacing() = 0;
 	
@@ -22,7 +29,10 @@ MidiChannelSelector::MidiChannelSelector() :
 					sigc::mem_fun(this, &MidiChannelSelector::button_toggled),
 					&_buttons[row][column],
 					channel_nr - 1));
-			attach(_buttons[row][column], column, column + 1, row, row + 1);
+
+			int table_row    = start_row + row;
+			int table_column = start_column + column;
+			attach(_buttons[row][column], table_column, table_column + 1, table_row, table_row + 1);
 		}
 	}
 }
@@ -54,12 +64,64 @@ SingleMidiChannelSelector::button_toggled(Gtk::ToggleButton *button, uint8_t cha
 	} 
 }
 
+MidiMultipleChannelSelector::MidiMultipleChannelSelector(uint16_t initial_selection)
+	: MidiChannelSelector(6, 4, 0, 0)
+{
+	_select_all.add(*new Gtk::Label(_("All")));
+	_select_all.signal_clicked().connect(
+			sigc::bind(sigc::mem_fun(this, &MidiMultipleChannelSelector::select_all), true));
+	
+	_select_none.add(*new Gtk::Label(_("None")));
+	_select_none.signal_clicked().connect(
+			sigc::bind(sigc::mem_fun(this, &MidiMultipleChannelSelector::select_all), false));
+	
+	_invert_selection.add(*new Gtk::Label(_("Invert")));
+	_invert_selection.signal_clicked().connect(
+			sigc::mem_fun(this, &MidiMultipleChannelSelector::invert_selection));
+
+	set_homogeneous(false);
+	attach(*new Gtk::HSeparator(), 0, 4, 4, 5, Gtk::FILL, Gtk::SHRINK, 0, 0);
+	set_col_spacing(4, -5);
+	attach(_select_all,       0, 2, 5, 6);
+	attach(_select_none,      2, 4, 5, 6);
+	attach(_invert_selection, 0, 4, 6, 7);
+	
+	_selected_channels = 0;
+	for(uint16_t i = 0; i < 16; i++) {
+		Gtk::ToggleButton *button = &_buttons[i / 4][i % 4];
+		if(initial_selection & (1L << i)) {
+			button->set_active(true);
+		} else {
+			button->set_active(false);
+		}
+	}
+}
+
 void
 MidiMultipleChannelSelector::button_toggled(Gtk::ToggleButton *button, uint8_t channel)
 {
-	if(button->get_active()) {
-		_selected_channels.insert(channel);
-	} else {
-		_selected_channels.erase(channel);
+	_selected_channels = _selected_channels ^ (1L << channel); 
+}
+
+void 
+MidiMultipleChannelSelector::select_all(bool on)
+{
+	for(uint16_t i = 0; i < 16; i++) {
+		Gtk::ToggleButton *button = &_buttons[i / 4][i % 4];
+		button->set_active(on);
 	}
 }
+
+void 
+MidiMultipleChannelSelector::invert_selection(void)
+{
+	for(uint16_t i = 0; i < 16; i++) {
+		Gtk::ToggleButton *button = &_buttons[i / 4][i % 4];
+		if(button->get_active()) {
+			button->set_active(false);
+		} else {
+			button->set_active(true);
+		}
+	}
+}
+
diff --git a/gtk2_ardour/midi_channel_selector.h b/gtk2_ardour/midi_channel_selector.h
index 5060087ea6..5b3e20e859 100644
--- a/gtk2_ardour/midi_channel_selector.h
+++ b/gtk2_ardour/midi_channel_selector.h
@@ -1,8 +1,10 @@
 #ifndef __ardour_ui_midi_channel_selector_h__
 #define __ardour_ui_midi_channel_selector_h__
 
+#include "boost/shared_ptr.hpp"
 #include "gtkmm/table.h"
 #include "sigc++/trackable.h"
+#include "gtkmm/button.h"
 #include "gtkmm/togglebutton.h"
 #include "gtkmm/label.h"
 #include <set>
@@ -10,7 +12,7 @@
 class MidiChannelSelector : public Gtk::Table
 {
 public:
-	MidiChannelSelector();
+	MidiChannelSelector(int no_rows = 4, int no_columns = 4, int start_row = 0, int start_column = 0);
 	virtual ~MidiChannelSelector() = 0;
 	
 protected:
@@ -38,12 +40,20 @@ protected:
 class MidiMultipleChannelSelector : public MidiChannelSelector
 {
 public:
-	const std::set<uint8_t>& get_selected_channels() const { return _selected_channels; }
+	MidiMultipleChannelSelector(uint16_t initial_selection = 1);
+	
+	const uint16_t get_selected_channels() const { return _selected_channels; }
 
 protected:
 	virtual void button_toggled(Gtk::ToggleButton *button, uint8_t button_nr);
 	
-	std::set<uint8_t> _selected_channels;
+	void select_all(bool on);
+	void invert_selection(void);
+	
+	Gtk::Button            _select_all;
+	Gtk::Button            _select_none;
+	Gtk::Button            _invert_selection;
+	uint16_t               _selected_channels;
 };
 
 #endif /*__ardour_ui_midi_channel_selector_h__*/
diff --git a/gtk2_ardour/processor_box.cc b/gtk2_ardour/processor_box.cc
index b2b1c3b538..9ce28d0aa6 100644
--- a/gtk2_ardour/processor_box.cc
+++ b/gtk2_ardour/processor_box.cc
@@ -352,6 +352,7 @@ Menu *
 ProcessorBox::build_processor_menu ()
 {
 	processor_menu = dynamic_cast<Gtk::Menu*>(ActionManager::get_widget("/processormenu") );
+	assert(processor_menu != 0);
 	processor_menu->set_name ("ArdourContextMenu");
 
 	show_all_children();