Teac A-3340S - Page 59

A-3340S ELECTRICAL ADJUSTMENTS
Outlined procedures refer only to FRONT channels (L1/R3).
The same procedures also apply to REAR channels (L2/R4).
Before performing checks set all head function selector switches to NORMAL. position.
OdB=0.775V
ADJUSTING ‘spy
MODE | POINT LOCATION
(on P.CB) Ref. No —
SIGNAL |MEASUREMENT
ne SOURCE | CONNECTION INSEROC HONS
Power Supply Peer VTVM between 1.Remove wooden sides and REAR’ TOP and Bottom panels ye fe aod
Check & Adj. ° TP 50 and ground | 2-Power on fon eee
3. Adjust for +23V DC -SUPPLY)
TEAC Test Tape VTVM & 1. Tape SPEED SW at LOW play Read ie
Head YTT-1003 Oscilloscope 2. Adjust for max. indication itn ots ; Check Potnt
Adjustment 16 kHz Tone and to OUTPUT jacks 3.Less than 45 _ out of phase at scope at 10 kHz. (on head ass'y) j {
10 kHz {Less than 90° on REAR channels)
Specified 1. OUTPUT controls at 8 (3 o'clock) position oe gee. -
Output level TEAC Test Tape 2. Adjust VR's for 0 dB at OUTPUT jacks. (on LINE ® # z :
Settin is i ifi :
1g YTT-1003 (This is the Specified Output level.) PHONE AMPL)
400 Hz 7 = a r
0 @B VR-202
VU Meter VR-204
Test Tone fi PLAY
Calibration 1. Adjust for 0 VU on the VU Meters (on LINE, ®
VTVM to OUTPUT PHONE AMPL.)
jacks r
TEAC Test Tape VR-102 PEs 8
YTT-1003 vrioa LOW @ cal
Frequency (LOW Speed) 1.Compare the readings obtained on the VTVM with response Limits on POWER SUPPLY PC BOARD
Response given in Fig. 3 VR-101
(Playback) ks ed Tape 2.Set the tape SPEED SW to match test tape for both speeds. vr-io3 MIGH ©
5 EQ,
HIGH Speed i
( peed) MIC AMPL)
Monitor AF oscillator to 1. Set LINE controls to max.
Level LINE IN jacks 2. OUTPUT SW’s to SOURCE.
Sorting 400 Hz 3. Adjust the VR's to obtain the specified output level of 0 dB at VR-301
—18 dB(97mV) OUTPUT jacks. VR-304 ®
= aa 1 (on REC,
ecitie
aia javal VTVM to OUTPUT 4. \ncrease input signal level to —8 dB (308mV) Stop METER AMPL.)
Setting jacks 5. Adjust LINE controls for 0 dB at OUTPUT jacks. Test Potnt
400 Hz : ji =.
—8 dB(308mV) VR-302
VU Meter 6, Check VU Meters for 0 VU indication VR-305
Level Check 7.1€ necessary, adjust VR’s for 0 VU indication on the VU Metes (on REC,
METER AMPL.)
RECORD PERFORMANCE
VTVM or oscillo- 1,Use TEAC Test Tape YTT-8013.
scope from ground 2.RECORD MODE SW's———> ON L-302 (L-ch)
Bias Trap to the junction of L-| 3,SPEED SW---—-———> Low L-304 (R-ch)
Adjustment 302/C-312(L-ch) or | 4.Depress REC and PAUSE button (on REC, ®
F L-304/C-330(R-ch) 5.RECORD BIAS and EQ SW-> 1. METER AMPL.)
NO signal See Fig 2 for 6. Adjust coils for min. on VTVM or scope. REC/PAUSE
test Point Location
Bias Leakage 7. Adjust coils for min. bias leakage reading at OUTPUT jacks Spec. [i201 L202
Check —40 dB or tess. (on LINE, ® on REC,METER AMPL. PC BOARD
1 PHONE AMPL.) i
8, OUTPUT (MONITOR) SW's > TAPE Depress P bdotton.
Record AF oscillator to VTVM and 9. Adjust Record Head azimuth screws for max. indication on output ,
Head "| LINE IN jacks Oscilloscope to VTVM. Record:Azimuth :
Azimuth 5 kHz OUTPUT jacks 10.Compare phase difference between output of L and R channel to sores. : See Fig. 2
Adj. ~18 dB(97mV) insure that phase difference is 45° or less. (on: Head <2es'y)
(Less than 90° on REAR channels)
; 11.While recording, adjust capacitor VC-501/503 for peak reading on VC-501 * (VC-601)
Bias 1 the VTVM. VC-503 * (VC-603)
Adjustment 12. Then turn the capacitor clockwise until the signal level decreases {on BIAS ®
| by 2.5 dB from the peak. PC BOARD A)
4
7 kHz \ S
a = = —— =. a ar eee — =
—18 dB le z
VIVM to VC-502 *(VC-602 é
Bias 2 OUTPUT jacks | 13, Change to TEAC Test Tape YTT-8003 or equivalent. voces Seem 5
Adjustment 14. Set REC BIAS and SW to 2. , (on BIAS ® a
15, Repeat step 11 and 12 except adjust VC-502/504, PC BOARD A)
Record 400 Hz 16,Use TEAC Test Tape YTT-8013. a R303
Level —8 dB 17. REC BIAS and SW to 1. ¥Ra06 ©
Set (308mV) 18. Adjust VR's for 0 dB on VTVM. (on REC,
mi METER AMPL.)
: |— eee ae : = eons
Frequency 40 Hz to 19. While recording input signals swept from 40 Hz to 18 kHz or
Response 18 kHz 20. Measure the playback output levels on the VTVM. Levels shall be g
—28 dB (31 my) within limits shown in Fig. 4 i L-301 z
(Overall) (LOW Speed) L303 3 {
REC BIAS SW ® § t
at? AO Hz te 21.Set SPEED SW to HIGH (on REC, 3 ry
REC EQ SW 22 kHz 22.Repeat step 19, but increase frequency to 22 kHz. METER AMPL.) “10) 1 '
at? 23.'f response is not within limits in. applicable chart in Fig. 5 i aes Lt
(HIGH Speed) i : | ||
just coils for best response : i H | | } La
7 r: @ : as Lo . ome 16K Bae
VTVM to j 315 40 50 63 100125 500
pected! OUTPUT jacks No adjustment avail- ees a
{Overall} 24.Use TEAC Test Tape YTT-8003 (or equivalent) on the unit grit A ates ee, te Fig. 3
Repeat abv. ‘ not within limits
REC BIAS SW Signals inputs 25.Set REC BIAS SW to 2. t Bi 4 :
at 2 8 7 26. Repeat steps 19, 22 ia as 2 ney
REC EQ SW ee See: Fig: aI T 11
at 1 ; OVERALL 7-3Zips (LOW)
* Designation for REAR channel +14. +
adjustment, *s | | u
Adjust on the BIAS PC BOARD B 1 |
@ +5)
z +4 ° 43,
5 a i : x4
a 40 is} ol T Tak
* sof tt
Lid AY
2 2 .
Amp PC Board Locations and Adjustment Points 68 a a
v ze
Fig. 4
ADJUSTMENT E | Ml ia peo Te Pails ULI iy altel ie] 7
7 OVERALL I5ips (HIGH)
‘ ERT RIGHT
Nas be 4. I: Bs G oxy
EQ, MIC AMPL N REC.METER AMPL |. | P.B-EQ HIGH SPEED 7 | | |
— =- 2. |P.B.EQ LOW SPEED
@ +5}—t45 - 1
3. BIAS TRAP Ae : 7 8
4. P.B.LEVEL Bol [ealeets - : lL,
5. |P.B.METER LEVEL z A i
FRONT [@g;ANNELS san ees ma
6. RECORD LEVEL L
mE
Te MONITOR LEVEL L
50 100 500 « 5K 40K 20K SOK
8. | REC METER LEVEL SeenOENCe Ince
9: RECORD EQ Fig. 5
0. BIAS TRAP
& BIAS ft ADJ
ne SIMUL-SYNC
DUMMY COIL (Fixed) meant I
[. 44th
DUMMY COIL (Fixed) rrr (PLAYBAC
al cope Bee ee
‘ ae
+10/-— se +
aa
+5) oe aaa
z ad
1° aa
é aes ele
Fd “te
i i
a ae Ea
1-442 i i ae
we 5K 63K 10K BOK
FREQUENCY IN Hz
Bottom view of PC Board