diff --git a/artiq/dashboard/waveform.py b/artiq/dashboard/waveform.py
index 0201b5f34..e27ea0f10 100644
--- a/artiq/dashboard/waveform.py
+++ b/artiq/dashboard/waveform.py
@@ -46,12 +46,14 @@ class _AddChannelDialog(QtWidgets.QDialog):
         grid = QtWidgets.QGridLayout()
         self.setLayout(grid)
 
+        self._channels_mgr = channels_mgr
         self._channels_widget = QtWidgets.QTreeView()
         self._channels_widget.setHeaderHidden(True)
         self._channels_widget.setSelectionBehavior(
             QtWidgets.QAbstractItemView.SelectItems)
         self._channels_widget.setSelectionMode(
             QtWidgets.QAbstractItemView.ExtendedSelection)
+        self._channels_widget.setModel(self._channels_mgr)
         grid.addWidget(self._channels_widget, 0, 0, 1, 2)
         cancel_btn = QtWidgets.QPushButton("Cancel")
         cancel_btn.clicked.connect(self.close)
@@ -66,20 +68,13 @@ class _AddChannelDialog(QtWidgets.QDialog):
                 QtWidgets.QStyle.SP_DialogApplyButton))
         grid.addWidget(confirm_btn, 1, 1)
 
-        self._model = Model(dict())
-        channels_mgr.add_setmodel_callback(self.set_model)
-
-    def set_model(self, model):
-        self._model = model
-        self._channels_widget.setModel(model)
-
     def add_channels(self):
         selection = self._channels_widget.selectedIndexes()
         channels = []
         for select in selection:
-            key = self._model.index_to_key(select)
+            key = self._channels_mgr.index_to_key(select)
             if key is not None:
-                width = self._model[key].ref
+                width = self._channels_mgr[key].ref
                 channels.append((key, width))
         self.accepted.emit(channels)
         self.close()
@@ -668,8 +663,7 @@ class WaveformDock(QtWidgets.QDockWidget):
         self.setFeatures(
             QtWidgets.QDockWidget.DockWidgetMovable | QtWidgets.QDockWidget.DockWidgetFloatable)
 
-        self._channels_mgr = LocalModelManager(Model)
-        self._channels_mgr.init({})
+        self._channels_mgr = Model({})
 
         self._devices = None
         self._dump = None
@@ -745,12 +739,7 @@ class WaveformDock(QtWidgets.QDockWidget):
 
     def _update_log_channels(self):
         for log in self._state['logs']:
-            self._channels_mgr.update({
-                "action": "setitem",
-                "path": "",
-                "key": log,
-                "value": (0, "log")
-            })
+            self._channels_mgr[log] = (0, "log")
 
     def on_dump_receive(self, data):
         decoded_dump = comm_analyzer.decode_dump(data)
@@ -853,7 +842,9 @@ class WaveformDock(QtWidgets.QDockWidget):
     def init_ddb(self, ddb):
         self._ddb = ddb
         addr = None
-        self._channels_mgr.init(comm_analyzer.get_channel_list(ddb))
+        channel_list = comm_analyzer.get_channel_list(ddb)
+        for k, v in channel_list.items():
+            self._channels_mgr[k] = v
         for name, desc in ddb.items():
             if isinstance(desc, dict):
                 if desc["type"] == "controller" and name == "core_analyzer":