diff --git a/4410-4412.tex b/4410-4412.tex
index 405bd50..c98de35 100644
--- a/4410-4412.tex
+++ b/4410-4412.tex
@@ -821,16 +821,16 @@ In the following example, the amplitude of DDS is proportional to the ADC input
 First, initialize the RTIO, SU-Servo and its channel.
 Note that the programmable gain of the Sampler is $10^0=1$, the input range is [-10V, 10V].
 
-\inputcolorboxminted{firstline=12,lastline=19}{examples/suservo.py}
+\inputcolorboxminted{firstline=10,lastline=17}{examples/suservo.py}
 
 Next, setup the PI control as an IIR filter. It has -1 proportional gain $k_p$ and no integrator gain $k_i$.
 
-\inputcolorboxminted{firstline=20,lastline=27}{examples/suservo.py}
+\inputcolorboxminted{firstline=18,lastline=25}{examples/suservo.py}
 
 Then, configure the DDS frequency to 10 MHz with 3V input offset.
 When input voltage $\geq$ offset voltage, the DDS output amplitude is 0.
 
-\inputcolorboxminted{firstline=28,lastline=32}{examples/suservo.py}
+\inputcolorboxminted{firstline=26,lastline=30}{examples/suservo.py}
 
 SU-Servo encodes the ADC voltage in a linear scale [-1, 1].
 Therefore, 3V is converted to 0.3.
@@ -838,7 +838,7 @@ Note that the ASF of all DDS channels are capped at 1.0, the amplitude clips whe
 
 Finally, enable the SU-Servo channel with the IIR filter programmed beforehand.
 
-\inputcolorboxminted{firstline=34,lastline=35}{examples/suservo.py}
+\inputcolorboxminted{firstline=32,lastline=33}{examples/suservo.py}
 
 A 10 MHz DDS signal is generated from the example above, with amplitude controllable by ADC.
 The RMS voltage of the DDS channel against the ADC voltage is plotted.
diff --git a/examples/suservo.py b/examples/suservo.py
index f700fab..2f05353 100644
--- a/examples/suservo.py
+++ b/examples/suservo.py
@@ -1,6 +1,4 @@
 from artiq.experiment import *
-from scipy import signal
-import numpy
 
 
 class SUServoExample(EnvExperiment):