Boss GT-1 Service Notes page 20

Sep. 2016
Input Test (AFAD)
8.
Input a signal like the following to the INPUT jack.
INPUT: 200-Hz sine wave at 0.218 Vpp (-20 dBm)
9.
Turn the knob 1 to set the value shown in the figure below to 0aE.
fig.test-14-2.eps
10. Verify that signals like the following are output from the PHONES jack.
PHONES L: 200-Hz sine wave at 200 to 300 mVpp
PHONES R: 200-Hz sine wave at 3.4 to 3.8 Vpp
11. Connect the oscilloscope to the OUTPUT L/MONO and R jacks and verify
that signals like the following are output.
OUTPUT L: 200-Hz sine wave at 200 to 300 mVpp
OUTPUT R: 200-Hz sine wave at 3.4 to 3.8 Vpp
* If you verify the each level of L and R channels one by one, measure it with a
plug being connected to another jack.
12. Detach the signal generator and the oscilloscope.
Residual Noise Test
13. Connect the 1/4-inch mono phone plug with 47 kΩ load resistor to the
INPUT jack and enter the Test Mode.
14. In the TEST MENU, select 14. AUDIO INPUT and press ENTER.
15. Connect the noise meters to the OUTPUT L/MONO and R jacks.
16. Turn the knob 1 to set the value shown in the figure below to 0AE. Also
press PREAMP to set muteL to o and press FX2/MOD to set muteR to o.
fig.test-14-3.eps
17. Verify that the residual noises are as the following values.
OUTPUT L: -93 dBm or lower (DIN-Audio)
OUTPUT R: -93 dBm or lower (DIN-Audio)
18. Change the connection of the noise meter to the PHONES jack.
19. Verify that the residual noises are as the following values.
PHONES L: -93 dBm or lower (DIN-Audio)
PHONES R: -93 dBm or lower (DIN-Audio)
20. Detach the noise meter.
20
AUX Test
21. Connect the oscilloscope to the OUTPUT L/MONO and R jacks.
22. Connect the signal generator to the AUX IN jack (L, R) and input signals
like the following.
AUX IN L: 200-Hz sine wave at 2.0 Vp-p
AUX IN R: 200-Hz sine wave at 2.0 Vp-p
23. Press PREAMP to set muteL to x and press FX2/MOD to set muteR to x.
24. Verify that signals like the following are output from the OUTPUT L/
MONO and R jacks.
OUTPUT L: 200-Hz sine wave at 4.7 to 5.3 Vpp
OUTPUT R: 200-Hz sine wave at 4.7 to 5.3 Vpp
25. Change the connection of the oscilloscope to the PHONES jack and verify
that signals like the following are output.
PHONES L: 200-Hz sine wave at 4.7 to 5.3 Vpp
PHONES R: 200-Hz sine wave at 4.7 to 5.3 Vpp
26. Detach the oscilloscope.
27. Press EXIT to return to the TEST MENU.
15. FACTORY RESET
This item is not required at the service.
the procedure in Performing a Factory Reset (p. 15) to execute a factory
reset.
16. AD NOISE
This item is not required at the service.
17. ENCODER DEVICE
This item is not required at the service.
* This item is added from ver. 1.06.
GT-1
Do not execute this item. Follow