Teac GE-20 - Page 6

CHECK AND ADJUSTMENT PROCEDURE
* Measurement remarks:
OdB=1V —
Output load impedance 10k ohms or more .
1-1 SPECIFIED INPUT/OUTPUT LEVEL
SETTING
PREPARATIONS: |
—EQ SW ........... OFF
—HI PASS SW ....... OFF
—LOPASS SW ....... OFF
— INPUT Controls ..... 0
— OUTPUT METER SW should be center position
— Both CHANNEL nieaeney Range knobs in 0 (click)
position.
. Connect an AC Voltmeter to the LINE OUT jacks.
2. Apply 1 kHz —10 dB (316 mV) to the LINE IN jacks.
3. Adjust OUTPUT level controls (CHAN 1 and CHAN 2)
for —10 dB (316 mV) at LINE OUT jacks.
—
1-2 VU METER CAL.
_ 4, Place the OUTPUT METER SW to the CHAN 1 position.
5. Adjust R103 for 0 VU reading on the VU Meter.
6. Change the OUTPUT METER SW to the CHAN 2 posi-
tion.
7. Check the 0 VU wading on VU Meter.
NOTE: After that, release the METER SW to the center
- position.
1-3 OVERLOAD INDICATOR ADJ.
8. Place the INPUT Level controls to maximum position.
9. Apply a 1 kHz +5 dB (1.78V) to the LINE IN jacks.
10. Check that the OVERLOAD Indicator lights at full in-
tersity.
11. Also, check that the OVERLOAD Indicator goes out
when the Input level is +3 dB (1.41V).
12. If adjustment is necessary, adjust R101/102 on EQ
AMP PCB ASSY.
14 FREQUENCY RESPONSE CHECK
13. Place the INPUT controls to the 0 (center) position.
14. Output/Input levels should be at the specified level
(—10 dB) settings.
15. Apply signal swept from 20 Hz to 30 kHz.
16. Check the frequency response, is within the Response
limits +0.5 dB. |
1-5 S/N RATIO CHECK
17. Ground LINE IN jacks.
18. OUTPUT and INPUT controls should be at the specified
positions.
19. The AC voltmeter connected to the LINE OUT jacks
should indicate —92 dB (25.1pV) or less.
NOTE: This corresponds to Signal-to-Noise Ratio of 82
dB; Difference between residual noise of —92 dB ©
and specified level of —10 dB.
1-6 DISTORTION CHECK
20. Same conditions as above Item 1-5, step 18.
21. Apply a 1 kHz —10 dB (316mV) signal to the LINE IN
jacks.
22. Connect a Distortion Meter to LINE OUT jacks.
23. The distortion factor read on the distortion meter
should be 0.03% or less.
1-7 CENTER FREQUENCY VARIABLE
LIMITS CHECK :
24, Place the EQ SW to the ON (push) position.
25, Apply each center frequency signal at —10 dB (316 mV)
to the LINE IN jacks.
26. Slide the appropriate slider control knob up and down.
27. Check the center Frequency Response is within the vari-
able response limits +12 dB.
Voltage Conversion Procedure
(General Export Model)
If the AC power line (mains) voltage in your area
does not match the AC power requirements indi-
cated on the label attached to this unit or printed
on the packing carton, this unit must be adjusted
using the following procedure.
FIRST MAKE SURE THE AC POWER CORD IS
DISCONNECTED FROM THE AC OUTLET OR
POWER SOURCE.
1. Remove the top cover of the unit by removing
2 rear screws.
2. Locate the voltage selector plug near the trans-
former inside the unit.
3. Pull out the plug and reinsert it so that the de-
sired voltage appears in the cut-out window of
the plug. |
4. Replace the top cover of the unit.