Nakamichi CR-2 User manual

Service
Manual
Nakamichi
Nakamichi

CONTENTS
Ne
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10.
11.
12.
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1.1.
General 6 is2c6%, Siecearad oki tirade enersed gabon eiteus- ba Matis PULA WRAN Ge db iatateig doe Sy tas Beat ldr hl cad Pe ai eae one the 1
Removal Procedures ......... 0.002 eee eeeneceee acne sear Beebe eto: ep CURIS Br cso Maa be, Wee thea BLE Soha WS 3
2 21. Top Cover Ass’y and Bottom Cover Ass’y ... 0.00.00 0c ce eee eee ee ee eee ee eae 3
2. (2. Cassette.Case: Cover ASS’ Ys joing p85 a o-2 Ms aap ee) shield ac 80. kG 8 Pada Hla Sid ow Sdn Wake ae eet Sa ee 3
2. 3. Mechainism: Ags) ys. 525 02: eta deck ae esate ta, ohh ae Rice b yds Sy wap eed nd MOPS Sr Baa ate ee dW ck eecal dees hob ace Be 3
2.0 A; Pin Jack P.C.B, Ass’y and Main P.C.B. Ass’y 2.0... ee tee ee ee nee 3
2. 5. Front:Panel 5520-930 sae psee: hana avis, ig ae dpe lateiere Gok HR Buelavel w FG RVR we Bw ee ee ees 4
2. 6. Bias Tune Volume P.C.B. Ass’y 2... 0. ee ee ete eee eee ae 4
25° Ts Control: PC IBM Assy. iccats Seg Pid tase so ia ies Blea olay Oh, Bae ee Oe Re RN ay al tos sca cee echo det 4
2. 8. Power Switch dome: ais écsc. soe ob aco. dyer eile 6 as ale. hive dudes SB Gebel Doteea! Bote aA AS UE eae es ndtias % 4
est. Tapes and Gauges «5.0.00 oy shar sca cease. a bee ale bedee Ng See. Bla we Oh aa 0 Sele Ca Bae a ed ween Weed ae ha a Ra 5
Mechanical Adjustments .... 00.00.00 ccc ee ee ee nee eee eee eee ee ee enn ee eee nen 5
4. 1. Tape Guide Height Check for Record/Playback Head and Erase Head ...............000004 5
4, Head Base Stroke Check 1... 0... 0. cece ee ee ee ee eee eee eee eee n nes 5
4. 3 Record/Playback Head Azimuth Alignment and Height Check .............0.0 0000 eeeeee 5
4, 4 Pressure Adjustment of Pressure Roller... 0... ee eee ee eee eee 6
4, 5 Tape Pravelling Chee 225525, sos 5a, pide iets eid so aten ae tes ne ine lag ata oleh dae Se BO Ie te Als seemed daha Bhat 6
4. 6 Eject Damper Adjustment ........ 0.0 cc cc ee ee eee ew eee ee eee tet e en ae 6
4. 7 Reel Motor Speed Adjustment in Play Mode .......0. 0.0.00 eee ence ee eee eens 6
4, ; Tape: Speed: Adjustment: i: 3>5- ste lactase d h8 econo evel 5, 28e- erco tae. Spe Sat eh ends ane or eluate Soda adi weatk 6
4. 9. TAM DriC atin esd scien Setar ate feak ha Wer cf eco Wal bee eteye wow a ae SVE edb a Ae WEE tee eee hake carly 6
Parts Location for Electrical Adjustment... 0.0.0.0... 2c ee ee ee eee een ee teen n nee q
Electrical Adjustments 2. 3 6'o58.5. 0.5.46 sn Que Gave 5 cenit p Soe oOo. ee. oo Doar een, He ouy cortenier. dear hard iw Ghia! abehar ba he 8
Mechanism Ass’y and Parts List... 0... ee ee ee eee ee teen eee een n nee 11
7 1. DY NUNSIS:. 4.4 «. siece cd Seitid GoM faves se at wore ahow hi WEGR EE coe ausah re ravine alae eB MaNMG Sa Ba Berd Saas here aa d eA g dc 11
7 2, Chassis: Ass'y (A010), osteo la Aah ecb ete Bales Ga EE hou) olf enb ane a alata bb Le etane eee 2 12
7 3, Bottom: Cover :Ass’y: (A02) icc isacs. trig a GS seas Saw Bahn WR oo Scale “eS a eee eke 12
7 4, Mechanism ‘Ass’y (B01): <6. 2-4 ¢ 66 sees Seo ew ele ee blab oe RS oa ee a alae ek 5 13
7. 6. Front Escutcheon Ass’y (B02) 2.0... 2... ec ee ee eee eee ee ee eee eee eee 14
Mounting Diagrams and Parts List .. 2.0.0... 2. ec ee ee eee ee ee eee ee nn eee ane eae 15
8 1. Buge’P.C:B: Assy 42:0 5. shen o5Syalerwcte hae aiecy nce se We tucenee Wak Bia Gd, OE Wa ble eo aena ete ws 15
8. 2. Pitt. dack: P.C. Bz Ass?¥. 23.05 set ee 6 ge ete es wd Se bee 0S Oe Sk 0 be ata eee Se Ee ae el lacs 15
8. 3. Input Volume P.C.B, Ass’y 2... 0. cc eee et eee eee eee nae 15
8 4 Output: Volume’ P;C.B, Ass’ Yo 55 96s d Sie eg ere, 8 New Ga voces lee adda ae Wn Rod ae as 16
8. 5 Headphone P.C.B. Ass’y. 1... ce ee ee eee ee eee eee ere eee eeeeeeenes 16
8. 6. Bias Tune Volume P.C.B, Ass’y 1. ee eee eee ee eee eee eee ene ee 16
82 1% ~Shutoft PC Bu Ass y's g:cce-pat ait lee a deca ee Gas Bete a ght Seared even: acted bak eat iia hte. a lath 16
8. 8 Control P-C-Bs Ass’y 2 fen K tires tie koe teen eh elt Be wend dtd dace i Seativin, ae OS ee es ee 16
8 9. Main. PC) B. Ass’¥" icine dt e7n Sat 94, ae tyes ott ls eco ec dha Ee aoe Sone LS & ae eee ve de ise dda BH be 17
Schematic: Diagram... «0.3.5. d05 6b Ach ae we Rae ek Reno ep ee een 8% Abdel eG Ios wae idces Be) we el bee 19
ee IC: Block: Diagrams! onicti 2.234, sh50 0 -aeidis Sod A havaicds dea ele ecw Bed Peet dws oho NS ee ae hw ws Geel 19
9o5 2; Schematic: Diagrann: os. p5 eee otha. ee crite asa ina Mahea No, oy ib bend dn gar a ween lb dab beled SOE wth dence a 24
Wiring: Diagram ios. ioe escwa olen fee oe ebb be See een else ace wale ow APS ob glenda Ties Ba ater ose Bieacdh wy abudlades a ghe 25
Block Diagrams. o-.5 isc. eidie oe eae oe Fe ee oe Re ww ale Sedu os ade ea wet eee Vie alee gw ea Boers ele bua ose 26
1 oo. Amplifier. Section’ caine ko ted hs eek ada ek ese Ew! aM en eR Pa Rte: en ta be UL ge te Be bee eae aw 26
11. 2. Mechanism Control Section . 2... 0... 0c ee ee ee eee eet ee eee eee 27
Timing Charts and Eq. Amp. Frequency Response ...........0.0 0c cece ee eee nee ee eee ne renee 28
12. #1. “Timing Charts ® j.2.0,:0%5 asc: abou te lg ooeta SR eh eb we ale oe Goa eerns W elswa eed aed 4 Macken bebe Sides 28
12. 2. Eq. Amp. Frequency Response ..........0.0 00 ccc ee ne ee eee eens 29
SDECHICATIONS: | 5.4).55.56 ete. Bidet ered co Weg Saw acs dy oa ete on By oqec Ble’ de APD a 0, Bee pea we eel eter oad be ot 380
GENERAL
Voltage Selector
Voltage selector is installed on the rear panel for Other version of the Nakamichi CR-2.
This voitage selector can select 110, 127, 220, or 240 V at customer’s disposal.

1.2.
Schematic
Ref. No, Part No.
Package Ass*y and Accessory Ass’y
Description
Fig. 1
Schematic
Ref. No.
Description
01 OF04070A
OF04071A
OF 04072A
OF04100A
02 OF 04087C
03 OF 04088C
04 OF03684A
0D04046A
0D04047A
OM03457A
OM05101A
OM05070A
0OM05054A
OM05087A
OM05106A
OM05105A
OM05107A
OM05108A
0M05102A
0M05103A
Package Ass’y
Carton Box (CR-2)
Caxton Box (CR-2A)
Carton Box (CR-2E)
Carton Box (CR-20)
Packing L
Packing R
Poly-Sheet S
Warranty Card (CR-20)
User’s Pack (CR-20)
Voltage Label 240V (CR-2
(Australia) & CR 2E (UK))
Voltage Label (CR-2 (Saudi
Arabia))
Serial No, Label (CR-2A)
Serial No. Label (CR-2, CR-2E &
CR-20)
Point of Sale Label (CR-20)
UL Label (CR-2A)
LA Label (CR-2A)
Canada Label (CR-2A)
UL/Canada Label (CR-2A)
Shipping Label Los (CR-2A)
Shipping Label VAN (CR-2A)
BRE REE BN N NEBR RRR eRe Oe
0D03092B
0D04449A
0D04810A
O0D04766A
0D04780B
0D04781B
0D04785B
OD04796A
OD04795A
ODO04797A
0D04812A
0M03844B
DA04121A
Accessory Ass’y
Poly-Bag
Important Notice (CR-2, CR-2E
& CR-20)
Important Notice (CR-2A)
General Catalogue (CR-2A)
Owner’s Manual (English/
German/French)
Owner’s Manual (Japanese)
Price Card (CR-20)
Tape Catalogue (CR-2A)
Tape Catalogue (CR-20)
Warranty Card (CR-2A)
Tape Supplement
Power Cord Label (CR-2E (UK))
Pin Cord Ass’y
ee
Rte
Ft fed bd et ee

2.
REMOVAL PROCEDURES
2.1. Top Cover Ass’y and Bottom Cover Ass’y
Refer to Fig. 2.1.
(1) Loosen FO1 and remove F02 (Top Cover Ass’y).
(2) Loosen F03 and remove F04 (Bottom Cover Ass’y).
2.2.
Fig. 2.1
Cassette Case Cover Ass’y
Refer to Fig, 2,2,
ql)
(2)
Press FO1 (Eject Button) to open FOQ2 (Cassette Case Cover
Ass’y).
Pull FO2 (Cassette Case Cover Ass’y) upward,
Fig, 2.2
2.3. Mechanism Ass*y
Refer to Fig. 2.3.
ql)
(2)
(3)
Remove the Top Cover Ass’y and the Bottom Cover Ass’y
referring to item 2.1.
Remove the Cassette Case Cover Ass’y referring to item 2.2.
Loosen FO1 and FO2, remove FO3, and disassemble F04
(Mechanism Ass’y).
Fig. 2.3
2.4, Pin Jack P.C.B. Ass’y and Main P.C.B. Ass’y
Refer to Fig. 2.4.
(1) Remove the Top Cover Ass’y and the Bottom Cover Ass’y
referring to item 2,1.
(2) Loosen FO1 and remove FO2 (Pin Jack P.C.B. Ass’y).
(3) Loosen F083 and FO4, and lift FO5 (Main P.C.B. Ass’y).
Note: When installing the Main P.C.B. Ass’y, to facilitate
installation, place the Main P.C.B. Ass’y so that the tops
of switches on the Main P.C.B. Ass’y come in contact
with the ends of push buttons as shown in Fig, 2.5.
Fig. 2.4
Fig. 2.5

2.5. Front Panel 2.7, Control P.C.B. Ass’y
Refer to Fig. 2.6. Refer to Fig. 2.8.
(1) Remove the Top Cover Ass’y and the Bottom Cover Ass’y (1) Remove the Top Cover Ass’y and the Bottom Cover Ass’y
referring to item 2.1. referring to item 2.1.
(2) Remove the Cassette Case Cover Ass’y referring to item 2.2. (2) Remove the Mechanism Ass’y referring to item 2.3.
(3) Pull out FO1, FO2 and FO3, and loosen F04 and F05, (3) Remove the Front Panel referring to item 2,5,
(4) With pushing claws by hand as shown in the figure, remove (4) Loosen FO1 and F0O2 with a special nut driver or with pliers
F06 (Front Panel).
(5)
to set FO3 (Bias Tune Volume P.C.B. Ass’y) free.
With pushing FO3 (Bias Tune Volume P.C.B. Ass’y) in the
direction of the arrow, loosen F04, unhook F05, and remove
FO6 (Control P.C.B. Ass’y).
Fig. 2.8
2.6. Bias Tune Volume P.C.B, Ass’y 2.8. Power Switch Joint
Refer to Fig, 2.7, Refer to Fig, 2,9.
(1) Remove the Top Cover Ass’y and the Bottom Cover Ass’y (1) Remove the Top Cover Ass’y referring to item 2,1,
referring to item 2.1. (2) Pull FO1 (Power Switch Joint) upward to remove it,
(2) Remove the Main P.C.B. Ass’y referring to item 2.4,
(3) Remove the Front Panel referring to item 2.5.
(4) Loosen FO1 and F02 with a special nut driver or with pliers,
and remove F03 (Bias Tune Volume P.C.B. Ass’y).
Main PC.8.Assy
Fig. 2.9

3. TEST TAPES AND GAUGES
(1) 400 Hz Level Tape (DA09005B)
(2) 1kHz Track Alignment Tape (DA09007B)
(3) 10kHz PB Frequency Response Tape (DA09003B)
(4) 15 kHz PB Frequency Response Tape (DA09002B)
(5) 20 kHz PB Frequency Response Tape (DA09001B)
(6) 15 kHz Azimuth Tape (DA09004B)
(7) 3kHz Speed and Wow/Flutter Tape (DA09006C)
(8) Tape Travelling Cassette (DA09071A)
(9) Reference EXII Tape (DA09111A)
(10) Reference SX Tape (DA09110A)
(11) Reference ZX Tape (DA09109A)
(12) Head Alignment Gauge (DA09092B)
(13) Torque Gauge FWD (DA09082A)
4, MECHANICAL ADJUSTMENTS
4.1. Tape Guide Height Check for Record/Playback Head and
Erase Head
With use of a Head Alignment Gauge (DA09092B), tape guide
height check for the Record/Playback and Erase Heads shall be
made, wherein a small block shall be pushed straight down to the
base while in use of the Head Alignment Gauge (DA09092B),
Refer to Fig. 4,1.
(1) Record/Playback Head Tape Guide Height
(a) Load the base of the Head Alignment Gauge (DA09092B)
carefully and set the cassette deck in Play mode,
(b) Piace the small block of the Head Alignment Gauge (DAO-
9092B) on the base, :
(ec) Slide the smali block against the tape guide of the Record/
Playback Head, and check to insure that the block is accepted
by the tape guide,
(a) If not, loosen the screw and insert a shim (either 30 um
(0C80048A), 60 wm (0C80038A), or 100 um (0C80039A))
to raise the Record/Playback Head, then tighten and apply a
quantity of lock tight paint to the screw.
(2) Erase Head Tape Guide Height
(a) Load the base of the Head Alignment Gauge (DA09092B)
carefully and set the cassette deck in Play mode,
(b) Place the small block of the Head Alignment Gauge
(DA09092B) on the base.
(c) Slide the small block against the tape guide of the Erase
Head, and check whether the block is accepted by the tape
guide,
4.2. Head Base Stroke Check
Refer to Fig. 4.2.
(1) Load the base of the Head Alignment Gauge (DA09092B)
carefully, then push the base toward the Record/Playback
Head to eliminate the clearance between the reference pin
and the base,
(2) Setthe cassette deck in Play mode,
(3) Piace the small block of the Head Alignment Gauge (DAO-
9092B) on the base.
(4) Contact the small block with the Record/Playback Head
surface and the Erase Head surface, and check whether the
end of the small block is located within the specified toler-
ance as shown in Fig. 4.2.
4.3. Record/Playback Head Azimuth Alignment and Height Check
Refer to Fig. 4.1.
(1) Contact an AC voltmeter to the Output Jacks.
(2) Load a 15 kHz Azimuth Tape (DA09004B) and set the
cassette deck in Play mode,
(3) Tur the Azimuth Alignment Screw until the outputs of both
channels become maximum.
(4) Load a 1 kHz Track Alignment Tape (DA09007B) and set
the cassette deck in Play mode.
(5) Check to insure that the readings of both channels on the AC
voltmeter are below —25 dB.
If not, replacement of the Record/Playback Head will be
required.
(6) Apply a quantity of lock tight paint to the Azimuth Align-
ment Screw.
Alignment
Alignment
Gauge
Gauge

4.4. Pressure Adjustment of Pressure Roller
Refer to Fig. 4.3,
(1) In Play mode, measure the torque of the Pressure Roller and
check whether the torque is in a range of 320 +50 g-cm,
(2) If torque is out of the range, correct it by changing the instal-
lation point of the Pressure Rolier Spring.
4.5, Tape Travelling Check
Load a Tape Travelling Cassette (DA09071A) and set the cassette
deck in Play mode to check the followings:
(1) After more than 2 seconds, the fluctuation of the tape travel-
ling on the Record /Playback Head is small,
(2) Tape isin contact with the head sufficiently.
(3) Tape waving is small on the heads and pressure roller.
4.6. Eject Damper Adjustment
Refer to Fig, 4.4. Load a cassette tape, and with opening the
Cassette Case by pressing the Eject button and closing it by hand,
adjust the speed of damper action by the Damper Adjustment
Screw,
CCW: Damper moves fast,
CW: Damper moves slowly.
4.7, Reel Motor Speed Adjustment in Play Mode
(1) Load a Torque Gauge FWD (DA09082A) and set the cassette
deck in Play mode.
(2) After 5 to 10 seconds, adjust VR601 on the Main P.C.B. Ass’y
to obtain exactly 45 g-cm on the torque gauge,
4.8. Tape Speed Adjustment
Refer to Fig, 4.5.
(1) Connect a frequency counter to the Output Jacks,
(2) Load a8 kHz Speed and Wow/Flutter Tape (DA09006C) and
play it back,
(3)
Adjust
the
Tape
Speed
Adjustment
Volume
incorporated
in
the
Capstan
Motor
to
obtain
3,000
Hz
on
the
frequency
couter,
CCW: Motor drives slowly.
CW: Motor drives fast.
4.9. Lubrication
The tape transport is of a lubrication-free type mechanism, When
the following parts are replaced, apply the specified lubricant,
(1) Molykote (R) Grease (X5-6020)
Cam Motor Pulley
Thrust portion on the Capstan Shaft
(2) FLOIL GB-TS-1
Washer between Reel Hub Ass’y and Back Tension Spring
(3) Diamond Oil (EP-56)
Reel Hub Shaft
(4) Anderol 456
Capstan Shaft
Note: We suggest that you use the above specified lubricant or
equivalent type.
The company dealing in the above lubricant is as follows:
(a) Molykote (R) Grease (X5-6020)
Dowcorning Co., Ltd., 1-15-1 Nishishinbashi, Minato-
ku, Tokyo, Japan
(b) FLOIL GB-TS-1
Kanto Chemicals Co., Ltd., 2-7 Kanda Sakuma-cho,
Chiyoda-ku, Tokyo, Japan
(c) Diamond Oil (EP-56)
Mitsubishi Oil Co., Ltd., 1-2-4 Toranomon, Minato-ku,
Tokyo, Japan
(d) Anderol 456
Toyo Kokusai Oil Co., Ltd., 3-3-5 Hatchobori, Chuo-
ku, Tokyo, Japan
Fig. 4.3
Increase
Damper Adjustment
Screw
Decrease N
Increase
Capstan Motor on
Fig. 4.5

PARTS LOCATION FOR ELECTRICAL ADJUSTMENT
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Fig. 5

6. ELECTRICAL ADJUSTMENTS
Set the CR-2/2A/2E/20 as shown in MODE.
Balance -
Center
Bias Tune —
Center
Eq. - 70 us
Tape - ZX
MPX Filter
- OFF
Dolby NR
- OFF
Playback 1. Play back a Torque Gauge FWD, and after
5 to 10 seconds, adjust VR601 to obtain
44 + 1 g-cm on the Torque Gauge
at 25 degrees (45 + 1 g-cm at 20
degrees).
2. Check that the deviation of the torque
value is within +10 g-cm of the
center value.
Note: Torque adjustment must be done
after leaving the CR-2/2A/2E/20 for
one hour with the power switch
turned OFF.
Reel Motor
Speed
Adjustment
(Play)
Gauge FWD
(DA09082A)
Tape Speed Frequency | Playback Tape Adjust the volume incorporated in the
Adjustment |Speed Counter to] Eq. - 70 ps Speed capstan motor to obtain 3 kHz +15 Hz on
and Wow/ Output Adj. the frequency counter,
Flutter Jacks Volume
Tape (Capstan
(DA09006C) Motor)
Record, Pause 1. Feed in 400 Hz and adjust the Input
Level control to obtain 500 mV -1.2
dB on the AC voltmeter.
2. Adjust VR101 (VR201) so that the 0
dB segment of the level meter starts
illuminating.
Meter Level
Calibration
Record, Pause
MPX - OFF/ON
MPX Filter
Adjustment
1. Adjust the Input Level control to
obtain 500 mV (0 dB) on the AC
voltmeter.
2. Set the MPX Filter switch to ON and
adjust L101 (L201) to obtain minimum
reading on the AC voltmeter (minimum
reading will be less than -30 dB).
Record/ 15 kHz AC Volt- Playback Record/ |Adjust the Record/Playback Head Azimuth
Playback Azimuth meter to Eq. - 70 ps Playback|Alignment Screw to obtain maximum
Head Tape Output Dolby NR - Head readings for both channels on the AC
Azimuth (DA09004B) | Jacks OFF Azimuth jvoltmeter.
Alignment MPX ~- OFF Align-
ment
Screw
Playback 400 Hz AC Volt- Same as Adjust VR102 (VR202) to obtain 500 mV on
Level Level Tape|meter to above the AC voltmeter,
7
Jacks
Calibration] (DA09005B) | Output

Playback
Frequency
Response
Adjustment
Bias
Oscillation
Frequency
and Erase
Current
Adjustment
Level Tape/meter to
(DA09005B) | Output
10 kHz PB |Jacks
Frequency
Response
Tape
(DA09003B)
15 kHz PB
Frequency
Response
Tape
(DA090028B)
20 kHz PB
Frequency
Response
Tape
(DA090018B)
Frequency
Counter
between’
terminals
1 and 2
of CN2 on
Main P.C.B.
across the
additional
0.1 ohm
resistor
None AC Volt-
Playback
Eq. - 70 ps
Dolby NR -
OFF
MPX - OFF
Record, Pause | Main
Eq. - 70 ps
Tape ZX
Dolby NR -
OFF
MPX - OFF
1. Load a 400 Hz level tape, play it
back, and read the playback level.
Load 10 kHz, 15 kHz and 20 kHz PB
frequency response tapes and play
them back. Adjust the record/play-
back head azimuth to obtain maximum
readings for both channels on the
AC voltmeter with each tape.
Check that the playback levels are
as follows with respect to the level
for 400 Hz level tape.
10 kHz: -20 dB -2 to +2 dB
15 kHz: -20 dB -2 to +3 dB
20 kHz: -20 dB -2 to +4 dB
If the level at 20 kHz is out of the
range, adjust VR106 (VR206) to obtain
satisfactory results. VR106 (VR206)
compensates the playback frequency
response at 20 kHz as shown below:
| Approx. 5d8
10K 20K
Conduct step 6 "Record/Playback Head
Azimuth Alignment",
Connect an additional 0.1 ohm resistor
in series to the Erase Head and
connect the AC voltmeter across it,
Adjust T301 to obtain 105 kHz +1 kHz
on the frequency counter.
If bias oscillation frequency is above
106 kHz, short-circuit C317 and C318,
and re-adjust T301 again.
Adjust VR304 to obtain 17.5 mV (175 mA)
on the AC voltmeter. (16.5 + 1 mV (165
+ 10 mA will be accepted.)
After completion of the erase current
adjustment, re-check the bias
oscillation frequency.
Remove the additional 0.1 ohm resistor.
Bias Trap
Adjustment
(Record
Amp.)
Adjust L103 (L203) to obtain minimum
(remove meter to reading on the AC voltmeter.
input TP101,TP201
signals) on Main
P.C.B.