diff --git a/amodem/calib.py b/amodem/calib.py
index 42a6e58..8861b56 100644
--- a/amodem/calib.py
+++ b/amodem/calib.py
@@ -72,10 +72,10 @@ def detector(config, src, frame_length=200):
         else:
             msg = 'too {0} signal'.format(errors[flags.index(False)])
 
-        yield common.AttributeHolder(dict(
+        yield dict(
             freq=freq, rms=rms, peak=peak, coherency=coherency,
             total=total, success=success, msg=msg
-        ))
+        )
 
 
 def volume_calibration(result_iterator, volume_ctl):
@@ -90,7 +90,7 @@ def volume_calibration(result_iterator, volume_ctl):
     for index, result in enumerate(itertools.chain([None], result_iterator)):
         if index % iters_per_update == 0:
             if index > 0:  # skip dummy (first result)
-                sign = 1 if (result.total < target_level) else -1
+                sign = 1 if (result['total'] < target_level) else -1
                 level = level + step * sign
                 level = min(max(level, min_level), max_level)
                 step = step * 0.5
@@ -112,10 +112,11 @@ def iter_window(iterable, size):
 
 
 def recv(config, src, verbose=False, volume_cmd=None, dump_audio=None):
-    fmt = '{0.freq:6.0f} Hz: {0.msg:20s}'
+    fmt = '{freq:6.0f} Hz: {msg:20s}'
+    log.info('verbose: %s', verbose)
     if verbose:
         fields = ['total', 'rms', 'coherency', 'peak']
-        fmt += ', '.join('{0}={{0.{0}:.4f}}'.format(f) for f in fields)
+        fmt += ', '.join('{0}={{{0}:.4f}}'.format(f) for f in fields)
 
     volume_ctl = volume_controller(volume_cmd)
 
@@ -125,6 +126,8 @@ def recv(config, src, verbose=False, volume_cmd=None, dump_audio=None):
     result_iterator = volume_calibration(result_iterator, volume_ctl)
     for _prev, curr, _next in iter_window(result_iterator, size=3):
         # don't log errors during frequency changes
-        if _prev.success and _next.success and _prev.freq != _next.freq:
-            curr.msg = curr.msg if curr.success else 'frequency change'
-        log.info(fmt.format(curr))
+        if _prev['success'] and _next['success']:
+            if _prev['freq'] != _next['freq']:
+                if not curr['success']:
+                    curr['msg'] = 'frequency change'
+        log.info(fmt.format(**curr))
diff --git a/amodem/common.py b/amodem/common.py
index 00f6be9..eee5415 100644
--- a/amodem/common.py
+++ b/amodem/common.py
@@ -85,14 +85,3 @@ class Dummy(object):
 
     def __call__(self, *args, **kwargs):
         return self
-
-
-class AttributeHolder(object):
-
-    def __init__(self, d):
-        self.__dict__.update(d)
-
-    def __repr__(self):
-        items = sorted(self.__dict__.items())
-        args = ', '.join('{0}={1}'.format(k, v) for k, v in items)
-        return '{0}({1})'.format(self.__class__.__name__, args)
diff --git a/amodem/tests/test_calib.py b/amodem/tests/test_calib.py
index 03855ca..e959dd3 100644
--- a/amodem/tests/test_calib.py
+++ b/amodem/tests/test_calib.py
@@ -39,8 +39,8 @@ def test_too_strong():
     calib.send(config, p, gain=1.001, limit=32)
     p.buf.seek(0)
     for r in calib.detector(config, src=p):
-        assert not r.success
-        assert r.msg == 'too strong signal'
+        assert not r['success']
+        assert r['msg'] == 'too strong signal'
 
 
 def test_too_weak():
@@ -48,8 +48,8 @@ def test_too_weak():
     calib.send(config, p, gain=0.01, limit=32)
     p.buf.seek(0)
     for r in calib.detector(config, src=p):
-        assert not r.success
-        assert r.msg == 'too weak signal'
+        assert not r['success']
+        assert r['msg'] == 'too weak signal'
 
 
 def test_too_noisy():
@@ -57,8 +57,8 @@ def test_too_noisy():
     signal = np.array([r.choice([-1, 1]) for i in range(int(config.Fs))])
     src = BytesIO(common.dumps(signal * 0.5))
     for r in calib.detector(config, src=src):
-        assert not r.success
-        assert r.msg == 'too noisy signal'
+        assert not r['success']
+        assert r['msg'] == 'too noisy signal'
 
 
 def test_errors():
@@ -94,9 +94,9 @@ def test_drift(freq_err):
     src = BytesIO(common.dumps(signal))
     iters = 0
     for r in calib.detector(config, src, frame_length=frame_length):
-        assert r.success is True
-        assert abs(r.rms - rms) < 1e-3
-        assert abs(r.total - rms) < 1e-3
+        assert r['success'] is True
+        assert abs(r['rms'] - rms) < 1e-3
+        assert abs(r['total'] - rms) < 1e-3
         iters += 1
 
     assert iters > 0
diff --git a/amodem/tests/test_common.py b/amodem/tests/test_common.py
index cd49e60..bceb85a 100644
--- a/amodem/tests/test_common.py
+++ b/amodem/tests/test_common.py
@@ -54,14 +54,6 @@ def test_izip():
     assert list(common.izip([x, y])) == list(zip(x, y))
 
 
-def test_holder():
-    d = {'x': 1, 'y': 2.3}
-    a = common.AttributeHolder(d)
-    assert a.x == d['x']
-    assert a.y == d['y']
-    assert repr(a) == 'AttributeHolder(x=1, y=2.3)'
-
-
 def test_configs():
     default = config.Configuration()
     fastest = config.fastest()