diff --git a/TTS/tts/models/base_tts.py b/TTS/tts/models/base_tts.py
index c71872d3..6069eb26 100644
--- a/TTS/tts/models/base_tts.py
+++ b/TTS/tts/models/base_tts.py
@@ -10,6 +10,7 @@ from torch.utils.data import DataLoader
 from torch.utils.data.sampler import WeightedRandomSampler
 from trainer.torch import DistributedSampler, DistributedSamplerWrapper
 
+from TTS.config import get_from_config_or_model_args, get_from_config_or_model_args_with_default
 from TTS.model import BaseTrainerModel
 from TTS.tts.datasets.dataset import TTSDataset
 from TTS.tts.utils.data import get_length_balancer_weights
@@ -108,7 +109,9 @@ class BaseTTS(BaseTrainerModel):
             self.speaker_embedding.weight.data.normal_(0, 0.3)
 
     def get_aux_input(self, **kwargs) -> Dict:
-        """Prepare and return `aux_input` used by `forward()`"""
+        """Prepare and return `aux_input` used by `forward()`
+
+        If not overridden, this function returns a dictionary with None values"""
         return {"speaker_id": None, "style_wav": None, "d_vector": None, "language_id": None}
 
     def get_aux_input_from_test_setences(self, sentence_info):
@@ -323,7 +326,9 @@ class BaseTTS(BaseTrainerModel):
                 use_noise_augment=False if is_eval else config.use_noise_augment,
                 verbose=verbose,
                 speaker_id_mapping=speaker_id_mapping,
-                d_vector_mapping=d_vector_mapping if config.use_d_vector_file else None,
+                d_vector_mapping=d_vector_mapping
+                if get_from_config_or_model_args(config, "use_d_vector_file")
+                else None,
                 tokenizer=self.tokenizer,
                 start_by_longest=config.start_by_longest,
                 language_id_mapping=language_id_mapping,
@@ -428,3 +433,21 @@ class BaseTTS(BaseTrainerModel):
             trainer.config.save_json(os.path.join(trainer.output_path, "config.json"))
             print(f" > `language_ids.json` is saved to {output_path}.")
             print(" > `language_ids_file` is updated in the config.json.")
+
+
+class BaseTTSE2E(BaseTTS):
+    def _set_model_args(self, config: Coqpit):
+        self.config = config
+        if "Config" in config.__class__.__name__:
+            num_chars = (
+                self.config.model_args.num_chars if self.tokenizer is None else self.tokenizer.characters.num_chars
+            )
+            self.config.model_args.num_chars = num_chars
+            self.config.num_chars = num_chars
+            self.args = config.model_args
+            self.args.num_chars = num_chars
+        elif "Args" in config.__class__.__name__:
+            self.args = config
+            self.args.num_chars = self.args.num_chars
+        else:
+            raise ValueError("config must be either a *Config or *Args")