Analog Cassette Deck
1979
The TC 750 was the top cassette deck of Telefunken's 1978/79 Hifi line. Its innards are similar to the TC 650 resp. HC 3000, with two important additions:
The direct drive looks rather large, I've never dared to disassemble one so far, and there hasn't been a need to fix a capstan motor so far. The absence of a belt greatly enhances the reliability of the whole drive.
Radio/Phono/Tape (DIN); Microphone/Aux (DIN); Line in/out (4xCinch); Headphone (DIN); Remote Control (DIN)
(taken from the user's manual)
Tape Speed: | 4.75 cm/s +/- 1 % |
Frequency Range: | 30-18000 Hz (CrO2) |
30-16000 Hz (Fe2O3) | |
30-18000 Hz (FeCr) | |
30-18000 Hz (Metal) | |
Variation of Speed: | +/- 0.14 % (REC+PLAY) |
+/- 0.1 % (only PLAY) | |
Distortion Factor | <= 3 % (CrO2) |
<= 1 % (Fe, FeCr) | |
S/N Ratio with HIGH COM: | 78 dB |
Erase Damping: | >= 66 dB |
Erase Frequency: | 86kHz |
Reduction of max. High Frequency Level at 10 KHz: | <= 12 dB (CrO2) |
<= 12 dB (Fe2O3) | |
<= 10 dB (FeCr) | |
<= 5 dB (Metal) | |
L/R Channel Damping: | >= 35 dB |
Input Sensitivity: | <= 0.1 mV / kOhm |
Input Impedance: | 6 kOhm Radio/Micro |
470 kOhm Aux | |
220 kOhm Line | |
Output Voltage: | 1.2 V |
Output Resistance: | 10 kOhm Radio |
8.2 kOhm Monitor/Line | |
270 Ohm Headphome | |
Playback Deemphasis: | 3180 µs / 70 µs (CrO2) |
3180 µs / 120 µs (Fe2O3) | |
3180 µs / 120 µs (FeCr) | |
3180 µs / 70 µs (Metal) | |
Multiplex Filter: | 19 kHz Pilot Tone Suppression switchable |
Record Level Supervision | switchable |
(Limiter) | |
Semiconductors: | 19 Integrated Circuits |
57 Transistors (among them 2 FETs) | |
79 Diodes | |
6 Zener Diodes | |
2 Rectifiers | |
10 LEDs | |
Mains Voltage: | 220/110 Volts |
Frequency: | 50/60 Hz |
Dimensions: | 460 x 142 x 346 mm |
The TC 750 shares the relatively complex head sleigh mechanics with the CC 20: The solenoid's force is transferred via a couple of sticks and levers, and the bearings' grease hardens over time. It often feels as though the sleigh doesn't move at all, you won't get around removing all old grease from all bearings; the solenoid->sleigh mechanics mustn't provide any mentionable counterforce when you operate it manually. Especially, the sleigh must entirely glide back into the idle position without any outer 'help'.
The TC 750's power supply may also prove problematic (the first thing to check if the deck acts 'funny'): It contains a filter capacitor, rated at 40 volts, which is being operated near to its limits. I had a TC 750 where this cap was shorted. You may consider replacing it with a capacitor with a bit more 'headroom'...
(taken from the service manual)
ABS 802 | 349 355 009 | Basic Module BS 5829 |
---|---|---|
Position | Part No. | Designation |
BU 301/302/ | 309 679 922 | cinch socket |
1301/1302 | ||
BU 803/804 | 339 541 002 | DIN socket, 5 contacts |
BU 806 | 339 540 092 | DIN socket, 7 contacts |
C 341/804/1341 | 309 414 662 | Al-electr. cap. 22 µF/35 V |
C 348/501/1348 | 309 411 654 | Al-electr. cap. 10 µF/35 V |
C 349/1349 | 309 410 657 | Al-electr. cap. 4.7 µF/50 V |
C 354 | 309 414 741 | Al-electr. cap. 470 µF/50 V |
C 356/1356 | 309 411 674 | Al-electr. cap. 22 µF/16 V |
C 357/1357 | 309 410 655 | Al-electr. cap. 2.2 µF/50 V |
C 359/1359 | 339 510 021 | foil trimmer 8 P/60 P |
C 502/504 | 309 414 737 | Al-electr. cap. 2200 µF/40 V |
C 503 | 309 414 774 | Al-electr. cap. 2200 µF/25 V |
C 804 | 339 584 069 | Al-electr. cap. 100 µF/25 V |
C 807/808 | 309 410 102 | Al-electr. cap. 1 µF/50 V |
C 1354 | 309 414 695 | Al-electr. cap. 470 µF/25 V |
D 800/801/802 | 309 325 927 | diode 1 N 4148 |
D 803/804 | 339 525 003 | diode BZY 85 C 6 V 8 |
FU 501 | 309 627 918 | fuse T 800 mA |
FU 502 | 309 625 610 | fuse T 1.6 A |
GR 501 | 339 520 046 | selen rectifier B 30 C 800 B 2 |
GR 502 | 309 320 924 | rectifier B 40 C 1500/1000 |
IC 501 | 339 575 068 | IC UA 7824 |
IC 503 | 339 575 069 | IC UA 7824 |
L 301/1301 | 339 345 458 | choke coil BS 7 36 K |
L 302/1302 | 339 345 853 | filter coil 85/19 kHz 23 MH |
L 801 | 339 345 950 | oscillator coil 85 kHz |
R 378/1378 | 309 509 705 | variable resistor 50 KOhm |
R 804 | 339 505 951 | variable resistor 2.5 KOhm |
R 809 | 339 509 920 | variable resistor 5 KOhm |
S 804 | 339 440 950 | chamber switch, record/play, |
2+3 contacts | ||
S 807 | 339 440 952 | chamber switch, compl., |
record/play, 6 contacts | ||
T 306/307/ | 339 556 224 | transistor BC 548 C |
1306/1307 | ||
T 801 | 339 556 026 | transistor BD 135 |
T 802 | 309 001 114 | transistor BD 675 |
ABS 301/1301 | 349 355 003 | HIGH COM Module BS 5335 |
Position | Part No. | Designation |
C 1 | 309 411 703 | Al-electr. cap. 22 µF/6.3 V |
C 2 | 309 410 634 | Al-electr. cap. 4.7 µF/35 V |
C 8/11/18 | 309 412 644 | Al-electr. cap. 47 µF/16 V |
C 15 | 309 410 655 | Al-electr. cap. 2.2 µF/25 V |
C 17/20 | 309 411 647 | Al-electr. cap. 10 µF/16 V |
C 19 | 339 580 114 | Ta-electr. cap. 0.22 µF/35 V |
C 22 | 309 413 486 | Al-electr. cap. 100 µF/16 V |
IC 1 | 339 575 019 | IC U 401 B |
IC 2 | 339 575 020 | IC MC 14066 BCP |
ABS 821 | 339 364 982 | Output Amplifier Module BS 5355 |
Position | Part No. | Designation |
C 1/2 | 309 410 643 | Al-electr. cap. 2.2 µF/25 V |
C 3 | 309 411 677 | Al-electr. cap. 10 µF/25 V |
IC 1 | 339 335 855 | IC MC 1458 CP1 |
ABS 822 | 339 330 853 | Universal Amplifier Module BS 5309 |
Position | Part No. | Designation |
C 1/2 | 309 410 643 | Al-electr. cap. 2.2 µF/25 V |
C 3 | 309 411 677 | Al-electr. cap. 10 µF/25 V |
IC 1 | 339 335 855 | IC MC 1458 CP1 |
ABS 801 | 349 355 002 | Pre-Amplifier Module BS 5418 |
Position | Part No. | Designation |
BU 801 | 339 540 057 | DIN socket, 8 contacts |
C 3 | 309 411 677 | Al-electr. cap. 10 µF/25 V |
C 303/1303 | 309 411 674 | Al-electr. cap. 22 µF/16 V |
C 306/1306 | 309 411 659 | Al-electr. cap. 22 µF/25 V |
C 308/1308 | 339 584 096 | Al-electr. cap. 100 µF/3 V |
C 313/1313 | 309 410 642 | Al-electr. cap. 1 µF/50 V |
C 314/1314 | 309 461 996 | Ta-electr. cap. 0.47 µF/35 V |
C 1312 | 309 414 695 | Al-electr. cap. 470 µF/25 V |
R 326/1326 | 309 509 735 | variable resistor 25 KOhm |
S 801 | 339 440 953 | rec/play switch, complete |
S 802 | 339 440 957 | push button switch, 2-fold |
T 1/2/302/1302 | 309 001 242 | transistor BC 550 C |
T 301/1301 | 309 001 211 | transistor BC 550 B |
T 303/304/305/ | 339 556 224 | transistor BC 548 C |
306/1303/1304/ | ||
1305 | ||
IC 504 | 309 368 105 | IC 7818 UC 18 V |
ABS 803 | 339 335 956 | Function Selector Module BS 5348 |
Position | Part No. | Designation |
C 370/376/ | 309 410 642 | Al-electr. cap. 1 µF/50 V |
1370/1376 | ||
C 371/377/ | 309 411 654 | Al-electr. cap. 10 µF/35 V |
1371 | ||
C 373 | 309 410 717 | Al-electr. cap. 4.7 µF/63 V |
C 374 | 309 411 656 | Al-electr. cap. 22 µF/25 V |
C 378 | 309 414 694 | Al-electr. cap. 220 µF/25 V |
D 310/312/317/ | 309 325 927 | diode 1 N 4148 |
811/812/813/ | ||
1310 | ||
D 311 | 339 529 138 | diode BZX 55 C 2 V 7 |
D 313/314/315 | 309 327 022 | LED FLV 110 RT |
D 316 | 339 529 105 | LED FLV 310 GN |
R 393/1393 | 309 509 401 | variable resistor 10 KOhm |
R 403 | 309 504 921 | variable resistor 5 KOhm |
S 810/813 | 339 440 954 | toggle witch |
S 811 | 339 440 955 | toggle witch |
S 812 | 339 440 956 | toggle witch |
T 310/1310 | 339 556 087 | transistor BC 548 C |
T 311 | 339 556 225 | transistor NE 412 S |
ABS 807 | 339 335 958 | Motor Control Board Cpl. BS 5524 |
Position | Part No. | Designation |
C 439 | 309 410 643 | Al-electr. cap. 2.2 µF/25 V |
D 3/4/5/6 | 309 325 951 | diode 1 N 4001 |
IC 431/432 | 339 575 074 | IC NE 532 N |
MG 3 | 339 340 952 | playback magnet |
MG 4 | 339 340 953 | lateral slide magnet |
MG 5 | 339 340 954 | brake magnet |
R 449 | 309 509 047 | variable resistor 2.5 Ohm |
S 9,13 | 339 405 951 | set of contact springs, 1-pol. |
S 10 | 339 440 962 | locking switch, complete |
S 12 | 339 440 961 | micro switch |
ABS 809 | 349 355 018 | Mechanism Control Module BS 5754 |
Position | Part No. | Designation |
C 701 | 309 411 674 | Al-electr. cap. 22 µF/16 V |
C 702/719 | 309 411 645 | Al-electr. cap. 10 µF/35 V |
C 705/709/717/ | 309 410 642 | Al-electr. cap. 1 µF/50 V |
723/725/726 | ||
C 706/707/708 | 309 410 855 | Al-electr. cap. 2.2 µF/50 V |
C 716 | 309 410 668 | Al-electr. cap. 4.7 µF/35 V |
C 721 | 309 461 917 | Ta-electr. cap. 10 µF/16 V |
C 741/742 | 339 580 115 | Ta-electr. cap. 0.68 µF/35 V |
C 743 | 309 412 644 | Ta-electr. cap. 47 µF/16 V |
D 701-720/723/ | 309 325 927 | Si-diode 1 N 4148 G |
725-728/ | ||
731-734/ | ||
736-739/ | ||
742-754/ | ||
756-764/ | ||
766-769/ | ||
772/773 | ||
D 741 | 309 325 951 | Si-diode 1 N 4001 |
D 755 | 339 525 003 | Si-z-diode BZY 85 C 6 V 8 |
D 771 | 309 325 057 | Si-z-diode BZY 85 C 4 V 7 |
IC 702/703/ | 309 368 144 | IC MC 14001 CP |
706/708/711 | ||
IC 704 | 339 575 070 | IC MC 14011 CP |
IC 707 | 339 575 071 | IC MC 14043 BCP |
T 701-704/706/ | 339 556 224 | Si-transistor NPN BC 548 C |
708/711/716/ | ||
718/719/721 | ||
T 707 | 309 001 114 | Si-transistor NPN BC 675 |
T 709/714/717 | 339 556 079 | Si-transistor NPN BD135/16 |
T 712 | 309 001 115 | Si-transistor PNP BD 676 |
T 713 | 309 001 114 | Si-transistor BD 675 |
ABS 808 | 339 330 955 | Rewind Motor Control Board BS 5775 |
Position | Part No. | Designation |
C 741/742 | 339 580 115 | Ta-electr. cap. 0.68 µF/35 V |
C 743 | 309 412 644 | Al-electr. cap. 47 µF/16 V |
D 781/782 | 309 325 927 | Si-diode 1 N 4148 |
L 701/702 | 339 345 350 | anti-interference choke |
T 731/733/734 | 309 001 024 | Si-transistor PNP BD 136/16 |
T 732/736/737 | 339 556 079 | Si-transistor NPN BD 135/16 |
T 738 | 339 556 224 | Si-transistor NPN BC 548 C |
ABS 811 | 339 355 858 | Push Button Board BS 5756 |
Position | Part No. | Designation |
339 335 953 | push button lear, 6-fold | |
ABS 812 | 339 335 955 | Heatsink |
Position | Part No. | Designation |
IC 502 | 339 575 072 | IC C 7812 SPG, REG |
Miscellaneous | ||
Position | Part No. | Designation |
BU 803 | 339 540 091 | headphones socket, complete |
FU 1 | 309 627 912 | fuse T 160 mA |
FU 2 | 309 627 901 | fuse T 315 mA |
HSK 11 | 339 350 850 | R/P head 'sendust' |
J 1/2 | 339 370 951 | level meter, yellow |
LA 1/2 | 339 560 079 | miniature bulb 12 V 60 mA |
LA 3/4 | 309 621 971 | miniature bulb 12 V 80 mA |
LE 1 | 309 695 935 | mains cable |
LK 2 | 339 355 950 | erasing head |
M 1 | 339 300 954 | capstan DC motor |
M 2 | 339 300 951 | DC motor |
S 1 | 309 630 994 | mains switch, 2 contacts |
S 8 | 339 440 959 | push switch memory, 1 contact |
R 1/2 | 339 500 951 | double potentionmeter, complete |
TR 1 | 339 310 952 | mains transformer EI 78 A |