diff --git a/neurodamus/connection_manager.py b/neurodamus/connection_manager.py
index 87caf41f..a841b06a 100644
--- a/neurodamus/connection_manager.py
+++ b/neurodamus/connection_manager.py
@@ -1081,8 +1081,7 @@ def finalize(self, base_seed=0, sim_corenrn=False, *, _conn_type="synapses", **c
         n_created_conns = 0
 
         for popid, pop in self._populations.items():
-            attach_src = (pop.src_id == 0 or not pop.virtual_source  # real populations
-                          or pop.virtual_source and bool(sim_corenrn))  # Req'd for replay
+            attach_src = pop.src_id == 0 or not pop.virtual_source  # real populations
             conn_params["attach_src_cell"] = attach_src
             logging.info(" * Connections among %s -> %s, attach src: %s",
                          pop.src_name or "(base)", pop.dst_name or "(base)", attach_src)
@@ -1234,8 +1233,7 @@ def __init__(self, circuit_conf, target_manager, cell_manager, src_cell_manager=
     def finalize(self, base_seed=0, sim_corenrn=False, **kwargs):
         """Create the actual synapses and netcons. See super() docstring
         """
-        # CoreNeuron will handle replays automatically with its own PatternStim
-        kwargs.setdefault("replay_mode", ReplayMode.NONE if sim_corenrn else ReplayMode.AS_REQUIRED)
+        kwargs.setdefault("replay_mode", ReplayMode.AS_REQUIRED)
         super().finalize(base_seed, sim_corenrn, **kwargs)
 
     def _finalize_conns(self, tgid, conns, base_seed, sim_corenrn, **kw):
diff --git a/neurodamus/neuromodulation_manager.py b/neurodamus/neuromodulation_manager.py
index 020c34d6..f1524a49 100644
--- a/neurodamus/neuromodulation_manager.py
+++ b/neurodamus/neuromodulation_manager.py
@@ -2,7 +2,7 @@
 
 from .connection_manager import SynapseRuleManager
 from .connection import Connection, NetConType, ReplayMode
-from .core.configuration import GlobalConfig, SimConfig
+from .core.configuration import GlobalConfig
 from .io.sonata_config import ConnectionTypes
 from .io.synapse_reader import SynapseParameters, SonataReader
 from .utils.logging import log_all
@@ -35,7 +35,7 @@ def __init__(self,
     def finalize(self, cell, base_seed=0, *,
                  skip_disabled=False,
                  replay_mode=ReplayMode.AS_REQUIRED,
-                 base_manager=None, attach_src_cell=True, **_kwargs):
+                 base_manager=None, **_kwargs):
         """ Override the finalize process from the base class.
             NeuroModulatory events do not create synapses but link to existing cell synapses.
             A neuromodulatory connection from projections with match to the closest cell synapse.
@@ -60,16 +60,8 @@ def finalize(self, cell, base_seed=0, *,
             if syn_obj is None:
                 logging.warning("No cell synapse associated to the neuromodulatory event")
                 return 0
-            nc = None
-            # For coreneuron, create NetCon attached to the (virtual) source gid for replay
-            # For neuron, create NetCon with source from replay stim
-            if SimConfig.use_coreneuron:
-                nc = self._pc.gid_connect(self.sgid, syn_obj)
-                nc.delay = syn_params.delay
-                self._netcons.append(nc)
-            elif self._replay is not None:
+            if self._replay is not None:
                 nc = self._replay.create_on(self, sec, syn_obj, syn_params)
-            if nc:
                 nc.weight[0] = int(self.weight_factor > 0)  # weight is binary 1/0, default 1
                 nc.weight[1] = self.neuromod_strength or syn_params.neuromod_strength
                 nc.weight[2] = self.neuromod_dtc or syn_params.neuromod_dtc
diff --git a/neurodamus/node.py b/neurodamus/node.py
index ea15b859..f0fe4acc 100644
--- a/neurodamus/node.py
+++ b/neurodamus/node.py
@@ -774,25 +774,7 @@ def _enable_replay(self, source, target, stim_conf, tshift=.0, delay=.0,
 
                 logging.info("=> Population pathway %s -> %s. Source offset: %d",
                              src_pop_str, dst_pop_str, src_pop_offset)
-                if SimConfig.use_coreneuron:
-                    self._coreneuron_replay_append(spike_manager, src_pop_offset)
-                else:
-                    conn_manager.replay(spike_manager, source, target, delay)
-
-    def _coreneuron_replay_append(self, spike_manager, gid_offset=None):
-        """Write replay spikes in single file for CoreNeuron"""
-        # To be loaded as PatternStim, requires final gids (with offset)
-        # Initialize file if non-existing
-        if not self._core_replay_file:
-            self._core_replay_file = ospath.join(SimConfig.output_root, 'pattern.dat')
-            if MPI.rank == 0:
-                log_verbose("Creating pattern.dat file for CoreNEURON. Gid offset: %d", gid_offset)
-                spike_manager.dump_ascii(self._core_replay_file, gid_offset)
-        else:
-            if MPI.rank == 0:
-                log_verbose("Appending to pattern.dat. Gid offset: %d", gid_offset)
-                with open(self._core_replay_file, "a") as f:
-                    spike_manager.dump_ascii(f, gid_offset)
+                conn_manager.replay(spike_manager, source, target, delay)
 
     # -
     @mpi_no_errors