Nikko ALPHA 220 - Block Diagram

SW3:
DIRECT
INPUT
- NO
(3)'
J:1
...,
1:--
- - - - - - ~ - - - - -
~~V
~~ ~~~ ~ - - - - -" - - - - - - "- - - - - -
; 1
I +
FIRST STAGE
2ND STAGE
PRE DRIVER
VARIABLE
DRIVER '
3) I
WITH CURRENT
BIAS &
070 I 0703
705
MIRROR LIMITER 0723
725
I - 0707
, 709 0715
, 717 I . .
(DUALFET)
711713 719
721
L -----
---- -----------------------------
NFB
DC-SERVO
TO DRIVE AMP.
RIGHT CH. TRANSISTORS
0702
, 704, 706
, 7 10
, 712
0714, 7 I 6, 718
, 720, 722
C4.
726
--,
r=-
POWER
REGULATR + 125V
LEVEL
THERMAL INDICATOR
COMPo
LED DRIVE
ASS'
0727
729
0808
809
LED DRIVER
OVERLOAD
DETECT
DC DETECT I
PROTECTOR, MUTING &
RELAY DRIVE 080 I ~0807
TO POWER TRANSISTORS
": 58.
POWER
. SW I
TRANSFORMER
POWER SWITCH
AC LINE
POWER SUPPLY
"V' POWER INO "V' PROTECTION
IND
HEAD- PHONES ..JACK
Lt:.
SPEAKERS
RELAY
SPEAKERS
(")
:t:-
:t:-
::I=- r--
::I=- c:)