diff --git a/README.md b/README.md
index d10fd5d59..de24abe2f 100644
--- a/README.md
+++ b/README.md
@@ -15,6 +15,7 @@
 
 ## Setup
 
+All tested under:  
 * Ubuntu 16.04
 * python>=3.7
 * paddlepaddle>=2.1.2
diff --git a/README_cn.md b/README_cn.md
index 90a65c440..29aadbdf6 100644
--- a/README_cn.md
+++ b/README_cn.md
@@ -16,6 +16,8 @@
 
 ## 安装
 
+在以下环境测试验证过：    
+
 * Ubuntu 16.04
 * python>=3.7
 * paddlepaddle>=2.1.2
diff --git a/deepspeech/exps/u2_kaldi/model.py b/deepspeech/exps/u2_kaldi/model.py
index 60f070a3b..a2f062a18 100644
--- a/deepspeech/exps/u2_kaldi/model.py
+++ b/deepspeech/exps/u2_kaldi/model.py
@@ -233,7 +233,7 @@ class U2Trainer(Trainer):
             batch_frames_inout=0,
             preprocess_conf=config.collator.augmentation_config,
             n_iter_processes=config.collator.num_workers,
-            subsampling_factor=1,
+            subsampling_factor=0,
             num_encs=1)
 
         self.valid_loader = BatchDataLoader(
diff --git a/deepspeech/io/converter.py b/deepspeech/io/converter.py
index a02e06acb..e591a7935 100644
--- a/deepspeech/io/converter.py
+++ b/deepspeech/io/converter.py
@@ -55,6 +55,8 @@ class CustomConverter():
             xs = [x[::self.subsampling_factor, :] for x in xs]
 
         # get batch of lengths of input sequences
+        print(xs)
+        print(ys)
         ilens = np.array([x.shape[0] for x in xs])
 
         # perform padding and convert to tensor