Pioneer ct 720 service manual

Page 1

(U) PIONEER

Sefiice
(71451111131

CIRCUIT & MECHANISM

DESCRIPTIONS

. V _ h ' ,, - , ORDER NO.
The photo shows the model CT-720. ARP-003-0
STEREO CASSETTE TAPE DECK

T-7EU
CT-EED
CT-aao

I This Service Manual should be used together with the Service Manual for CT-GR and
7R, and for CT-4 and 5.

PIONEER ELECTRONIC CDHFDRATION 4-1, Msgurn l-Chcma, Maguro-ku. Tokyo 153 Japan
LLB. DION- 35:11:09:ch monA'nON BE Oxford Drwa Moonauhie, New Jersey 07074. USA.
Emilia ELECTRON": (WE) N.V. Luuchagen-Haven a 2030 Antwan], Eslglum

Bmn mica AuamuA u'rv. Lm. 178-184 Boundary Road. Eraesme. Vccoma 3155. Auscmha

YP ©OCT. 1981 Plinled in apan

Page 2

CT-720/520/320

1. CT- 720

Block Diagram

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Refer to the block diagram for circuit details. The Dolby NR processor output (pin 8 of
HA11226) is applied to the REC/PB head via the
1-1 S'GNAL PATHS REC muting circuit (Q306/Q307), the recording
Playback Mode amplifier (Q308) and a bias trap.
The signal from the REC/PB head is passed via . . _
the equalizer amplifier (Q301/Q302), a bilateral ° F "16°th Descnptmsi f t0 the

. - - Service Manual (CIRCUIT & MECHANISM
swrtch (10303), a flat amplifier (Q304) and MPX
filter to the Dolby NR processor (pin 2 of DESCRIPTIONS) for CT-6R
HA11226). The Dolby NR processor output (pin 8 and 7R"

of HA11226) is passed to the LINE OUTPUT via
another bilateral switch (10304) and the line
muting circuit (Q309/Q310).
Recording Mode

The LINE INPUT signal or MIC signal (mic
amplifier output) is passed to the Dolby NR
processor (pin 2 of HA11226) via the INPUT
level control (VR801), a bilateral switch (IC303),
a flat amplifier (Q304) and MPX filter.