Ashly FTX-1501 Stereo Amplifier User Manual


 
Operating Manual - FTX-1001, FTX-1501, FTX-2001, CFT-1800 Power Amplifier
8
7. REAR PANEL FEATURES
7.1 Inputs
The standard input panel of the FTX Series III
amps is equipped with balanced 1/4" tip-ring-sleeve (TRS)
phone jacks, balanced XLR jacks, and balanced screw-
terminal inputs. The three types of connectors are inter-
nally wired in parallel and may be used with balanced or
unbalanced connections. The inputs are configured for
pin 2 hot, meaning that a positive voltage applied to pin
2 will result in a positive output voltage across the speaker
terminals. Pin 2 of the XLR jack is equivalent to the tip
of the 1/4" TRS jack. An optional input transformer is
available on all FTX and CFT amplifiers.
Balanced Inputs
It is recommended that balanced input connec-
tions be used whenever possible to reduce ground-loop
and environment-induced hum and noise. The (+) signal
is on pin 2 of the XLR, and the tip of the phone jack. The
(-) signal is on pin 3 of the XLR, and the ring of the phone
jack.
Unbalanced Inputs
If an unbalanced input connection is used, then
the (-) connection (XLR pin 3) should be connected to
input ground ( XLR pin 1). If the 1/4" input jack is used
unbalanced, the use of a mono (tip-sleeve) plug will au-
tomatically tie the (-) connection to input ground. Never
float pin 2 or pin 3 when using an unbalanced signal.
Figure 7.1: Balanced Input Connections Figure 7.1a: Unbalanced Input Connections