Teac A-2300SD - Overall Frequency Response; Rec Bias #2 Frequency Response Check; Rec EQ #2 Level Set; Monophonic Recording

9-20 OVERALL FREQUENCY RESPONSE
1. Place the DOLBY NR SW to OUT position.
2. Place REC EQ SW and REC BIAS SW at #1 position.
3. Place Tape SPEED at 7-1/2 ips (HIGH) position.
4. Adjust the AF oscillator to obtain an Output level of
-28 dB at OUTPUT jacks.
5. Apply signals swept from 40 Hz to 24 kHz to the deck
while recording on a record Test Tape (TEAC
YTT-8013). Refer to response limits below.
6. Repeat the above procedure for 3-3/4 ips (LOW) using
signals from 40 Hz to 16 kHz.
7. If the response is not uniform, the heads should be
checked for accumulated oxide and dirt.
8. If heads are clean, the equalization coil L-402 (L-CH)
and L-404 (R-CH) should be adjusted.
9. Adjustment of coils should be done while in HIGH
position for both speeds.
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Fig. 9-11 Frequency Response Limits - Record -
10. P lace DOLBY NR SW to IN position.
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Fig. 9-12 Frequency Response Limits - Record -
9-21 REC BIAS #2 FREQUENCY RESPONSE
CHECK
1. Place the REC EQ SW to #1 position, BIAS SW to #2
position.
2. Place Tape SPEED SW to 7-1/2 ips (HIGH) position.
3. Thread a record Test Tape YTT-8003 on the unit.
4. Adjust VR-20 for best frequency response.
(adjusts both channels together)
5. Repeat Overall response check at LOW speed. Both
speeds refer to response Limits given in figure 9-11 and
9-12.
9-22 REC EQ #2 LEVEL SET
1. Thread a record Test Tape YTT-8003 on the unit.
2. Apply a 400 Hz signal at -8 dB to the LINE IN jacks.
3. Place REC EQ SW to the #2 position.
4. Place Tape SPEED SW to 7-1/2 ips (HIGH) position.
5. Adjust REC LEVEL CAL VR-503/506 (on the back
panel) for -1-0.8 dB at OUTPUT jacks.
9-23 MONOPHONIC RECORDING
1. Place the RECORD MODE SW L (or R, not both) to
ON and R (or L) to the OFF position.
2. Apply signals swept from 40 Hz to 24 kHz at —28 dB
to LINE IN jacks and record. Use record Test Tape
YTT-8003 or equiv.
3. If necessary, adjust L-20 (on the BIAS OSC PC Board)
for best response.
9-24SIGNAL-TO-NOISE RATIO (PLAYBACK)
1. OUTPUT controls should be at the Specified Output
Level settings.
2. Thread a blank YTT-8003 on the unit leaving the tape
outside the capstan and pinch Roller.
3. Hold the play supply reel stationary and depress the
play ( ► ) button.
4. The DOLBY .N R SW must be at OUT position.
5. The Test-Set (VTVM) connected to the OUTPUT jacks
should indicate listed below.
7-1/2 ips.52 dB (unweighted), 60 dB (weighted)
3-3/4 ips.50 dB (unweighted), 60 dB (weighted)
9-25 SIGNAL-TO-NOISE RATIO (OVERALL)
1. OUTPUT and LINE controls should be at the Specified
position.
2. Thread a blank Test Tape YTT-8003 on the unit.
3. Remove the AF oscillator from the LINE IN jacks.
4. Place the unit in the REC mode with “no signal"
applyied. Note the point on the index counter where
recording begins.
5. Rewind the tape to the beginning point and play it back.
6. The noise level as indicated on the Test-Set should be
readings listed below.
* DOLBY NR OUT position
7-1/2 ips.50 dB (unweighted), 53 dB (weighted)
3-3/4 ips.48 dB (unweighted), 50 dB (weighted)
* DOLBY NR IN position
7-1/2 ips.52 dB (unweighted), 62 dB (weighted)
3-3/4 ips.50 dB (unweighted), 62 dB (weighted)
)
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