Inputs – Directed Electronics Tube Driver System TD275/2150 User Manual
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I n p u t G a i n C o n t r o l
There is an Input Gain Control located on the end panel under the RCA
input jacks. This is not a volume control! This control matches the output
signal voltage of the source unit to the amplifier inputs.
By turning the control clockwise (to the right), the inputs of the amplifier
become more sensitive and will allow a weak signal of approximately 1/2
volt to drive the amplifier to full power. At the same time, while an amplifier
with its level control at maximum is able to drive a weak signal, it also picks
up and amplifies any noises lurking in the background, such as a brake light
pop,
alternator
whine,
or ignition
tick.
Increasing the signal voltage to the amplifier by using a high output source
unit, or a TUBE DRIVER LD-3, will increase the signal to noise ratio. By
turning the level control counterclockwise (to the left), the amp inputs will be
less sensitive. The amp will reproduce music at full power while making any
noise floor insignificant. Your T UBEDR I V E R accepts signal levels of up to
12 volts RMS.
S e t t i n g I n p u t Gain
1. Set the Input Gain Control to just above the lowest setting.
2. Turn the master volume on the source unit or pre-amp to almost full
volume.
3. With music playing, slowly increase each Input Gain Control until you
hear distortion. Turn down the Gain Control until the distortion stops.