Boss GT-100 Service Notes page 20

Mar. 2012
RETURN -> SEND (Signal Levels)
1.
Set the GND LIFT switch to GND.
2.
Connect the signal generator to the RETURN connector, and input the
following signal.
RETURN: 200-Hz sine wave at +10 dBm
3.
Connect the oscilloscope to the SEND connector, and verify that the
output value is as shown below.
SEND: 5.5 Vpp–6.5 Vpp
fig.osc-7.eps
4.
Press PAGE .
A screen like the one shown below is displayed.
fig.audio-2.eps
(AFAD: HI)
5.
Input the following signal to the RETURN connector.
RETURN: 200-Hz sine wave at -16 dBm
6.
Verify that the output value at the SEND connector is as shown below.
SEND: 3.8 Vpp–4.8 Vpp
fig.osc-7.eps
7.
Press PAGE twice.
A screen like the one shown below is displayed.
fig.audio-1.eps
20
RETURN -> SEND (Residual Noise)
1.
Connect the 1/4-inch phone plug equipped with 47-kΩ load resistor to
the RETURN connector.
2.
Connect the noise meter to the SEND connector, and verify that residual
noise is as shown below.
SEND: -94.0 dBm or lower (DIN audio)
or -96.0 dBm or lower (JIS A)
RETURN -> SEND (Mute Operation)
1.
Press WRITE.
A screen like the one shown below is displayed.
fig.audio-4.eps
(MUTE ON)
2.
Connect the signal generator to the RETURN connector, and input the
following signal.
INPUT: 200-Hz sine wave at +10 dBm
3.
Verify that the output signal at the SEND connector disappears.
fig.osc-9.eps
4.
Press WRITE.
A screen like the one shown below is displayed.
fig.audio-1.eps
(AFAD: ON)
5.
Detach the signal generator from the RETURN connector.
Impact Noise
1.
Press EFFECT, then press SYSTEM.
A screen like the one shown below is displayed.
fig.audio-5.eps
GT-100