8
ABSOLARE Hybrid Mono Amplifier User Manual 1.2
6. Operating the Unit
6.1. General Operation
Before turning on each Absolare Hybrid Mono Amplifier, be sure that all tubes are
installed and all cables are connected securely.
After turning each Amplifier on, the power indicator LED on the front face plate will
start to blink. You will not hear any sound until the indicator LED stops blinking to
illuminate continuously which indicates all the capacitors are charged and internal
voltages are stabilized.
Absolare Hybrid Mono Amplifiers will be ready to operate approx. 40 seconds after
turning on the power but attain full performance after 15 to 30 minutes.
There is requirement for matching tubes to optimise performance. You can try
different types / brands of 12AU7/ECC82 compatible tubes in left and right tube
positions within each Amplifier. Different tubes will impact sound quality. It is
important that the final selection of input tubes for one Amplifier are copied in the
other Amplifier, so that both left channel and right channels are identical.
6.2. SEL Switch
Selects the active input connection, XLR or RCA connector. The unselected input is
terminated with a 620
Ω resistor.
6.3.
‘PIN 1’
Switch
Selects whether the number 1 pin of the XLR connector will be connected to ground
(
GND
) or left unconnected (
FLOAT
). It is advised to set this switch to ground (
GND
).
Since there is no strict standard on XLR grounding, it might be necessary to use this
switch to solve some grounding problems. The XLR
’s outer connector casing is
connected to each A
mplifier’s chassis.
6.4. GND Switch
Selects whether the input signal ground will be directly connected to the chassis or to
a
‘lifted’ signal ground (a separate clean ground plane inside the amplifier, connected
to chassis through a filter). It is advised to set this switch to
SIGNAL
, unless there is a
ground related hum in your system.
