User Manual

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Part Names and Functions
1 2 3 4
1. IN jack: Connect a portable music player or similar device here.
2. VOL (VOLUME) knob: Used for adjusting the volume.
3.
jack: Connect a pair of headphones or stereo earphones.
4. ON/STANDBY switch: Turns on/off the device.
How to Use the Nu:Tekt HA-S
Do not connect headphones, an audio player or other device to the
jack or the IN jack before turning on the power.
1. Turn the volume all the way down (counter-clockwise), and set the
ON/STANDBY switch to the upper position to turn on the power.
If the NuTube does not light up, turn off the power immediately and
check to make sure that there are no mistakes in assembly.
TIP Note that the brightness of the Nutube may look different from left to
right.
2. Connect a pair of headphones or earphones to the
jack, and
connect an audio player or other device to the IN jack.
3. Adjust the volume using the VOLUME knob.
Turn the volume up gradually (clockwise) while checking the sound.
Adjusting the main circuit board
The main circuit board comes preadjusted at the factory. The main circuit
board generally does not need to be adjusted, but if you notice a difference
in volume between left and right, adjust VR 4, 5, 6, and 7 to balance the
levels between left and right. The tonal character will also change when
adjusting the sound. Adjust the settings to get the sound you like.
1
5
4
2
3
1. NFB switch: Setting the switch to “A” will set the circuit to a non-NFB
circuit. The harmonics present in the Nutube will be amplified to
create a sound that is even closer to that of a vacuum tube. Setting the
switch to “B” will enable the NFB circuit, offering a hi-fi sound.
Setting the switch to “A” will increase the output level, due to the
characteristics of the circuit .
The vacuum tube effect will change depending on the output level of
the device connected to the input of the HA-S. Although, the effect is
more prominent at higher levels, if the sound distorts, however, adjust
by lowering the levels.
2. BIAS(L)(VR6)
3. BIAS(R)(VR7): This sets the Nutube bias voltage. Adjust VR6 and 7
while listening to the sound, in order to achieve maximum volume.
4. Anode Load(L)(VR4)
5. Anode Load(R)(VR5): This adjusts the Nutube’s anode load resistance.
In general, the unit is used with VR 4 and 5 turned all the way to the
right. However, since the tonal character of the sound changes according
to the load resistance, adjust VR 4 and 5 to get the sound that you like.
TIP Turning the fixed resistors (VR 4, 5) all the way to the left will result in no sound.
TIP You may hear a crackling sound when turning the VR4, 5, 6 or 7 fixed
resistors while playing sound, but this is not a malfunction.