Mixing During Monaural Recording; Stereo Playback; Stereo Amplifier; Stereo Recording - TANDBERG 12 Service Manual

C
5.2.4 Mixing during monaural recording
R e f . b l o c k d i a g r a m f i g . 3 9 .
W e p r e s u m e t h a t t h e m i x e d p r o g r a m m e ( p r o g r a m m e
I a n d 2 ) i s t o b e r e c o r d e d o n c h a n n e l I ( u p p e r t r a c k ) .
P r o g r a m m e I i s c o n n e c t e d t o t h e l i n e i n p u t c h . I a n d
p r o g r a m m e 2 i s c o n n e c t e d t o t h e l i n e i n p u t c h . 2 .
The outputs from the iwo record preamplifiers are
c o n n e c t e d i n p a r a l l e l w h e n t h e f u n c i i o n s e l e c t o r
s w i t c h c h . I i s s e t t o p o s i t i o n R E C O R D a n d t h e f u n c -
tion selector switch ch. 2 is set to position AMP. The
two programmes are mixed and fed to the record
e q u a l i z i n g a m p l i f i e r a n d t h e r e c o r d h e a d c h . l . T h e
r e c o r d g a i n i s c o n t r o l l e d b y t h e v o l u m e c o n t r o l c h . l
a n d t h e i n p u t o f t h e e q u a l i z i n g a m p l i f i e r i n a m p l i f i e r
p o s i t i o n c h . 2 i s c o n n e c t e d p a r a l l e l t o t h e i n p u t o f t h e
r e c o r d e q u a l i z i n g a m p l i f i e r c h . l . T h e p o w e r o u t p u f
a m p l i f i e r c h . 2 i s c o n n e c t e d f o t h e i n t e r n a l s p e a k e r
when the speaker switch is set to position lNT.
T h e m i x e d p r o g r a m m e w i l l b e m o n i t o r e d t h r o u g h
both internal speakers with a reduced output through
t h e s p e a k e r c h . l . T h e o u t p u f g a i n o f f h e i n t e r n a l
s p e a k e r c h . 2 i s c o n t r o l l e d b y t h e v o l u m e c o n t r o l
c h . 2 .
T h e p r o c e d u r e f o r r e c o r d i n g t h e m i x e d p r o g r a m m e
o n c h . 2 i s t h e s a m e a s o u t l i n e d a b o v e , w i t h t h e f u n c -
tion selector switch ch. I in position AMP and the
f u n c t i o n s e l e c t o r s w i t c h c h . 2 i n p o s i t i o n R E C O R D .
N O T E : T h e l i n e i n p u t s a r e d i s c o n n e c t e d w h e n t h e
c o r r e s p o n d i n g m i c r o p h o n e p l u g i s i n s e r i e d .
5.2.5 Stereo recording
R e f . b l o c k d i a g r a m f i g . 3 9 .
The two function selector swifches (ch. i and ch. 2)
a r e s e t t o R E C O R D p o s i t i o n a n d t h e s p e a k e r s e l e c t o r
s w i t c h t o l N T .
T h e t w o s i g n a l s ( c h . I a n d c h . 2 ) p a s s t h r o u g h e a c h
r e c o r d p r e - a m p l i f i e r a n d r e c o r d e q u a l i z i n g a m p l i f i e r
to the record heads.
The connection between the outputs from the record
p r e - a m p l i f i e r s a n d t h e c o n n e c t i o n b e t w e e n t h e i n p u t s
o f t h e r e c o r d e q u a l i z i n g a m p l i f i e r s a r e d i s c o n n e c t e d
in stereo recording.
T h e i n t e r n a l s p e a k e r s ( c h . I a n d c h . 2 ) a r e c o n n e c i e d
i n s e r i e s w i t h R 2 l 0 a n d R 2 l l t o t h e o u i p u t o f t h e
p o w e r o u t p u t a m p l i f i e r s . W e a r e m o n i t o r i n g t h e r e -
c o r d i n g s i g n a l w i t h a r e d u c e d o u t p u t .
5.2. 6 Monaural playback, channel f or 2
R e f . b l o c k d i a g r a m f i g . 3 9 .
We presume that the recorded programme is played
b a c k f r o m c h . l .
The function selector switch ch. I is set to oosition
PLAYBACK and the function selector switch ch. 2 is
set to positron AMP. The speaker switch is in position
I N T .
T h e o u t p u t f r o m t h e p l a y b a c k p r e - a m p l i f i e r c h . I i s
c o n n e c t e d t o i h e i n p u t o f p l a y b a c k e q u a l i z i n g a m p l i -
f i e r c h . l . T h e o u t p u t f r o m t h e p l a y b a c k e q u a l i z i n g
amplifier ch. I is connected to the power output
a m p l i f i e r c h . I a n d t o t h e i n p u t o f t h e e q u a l i z i n g
a m p l i f i e r c h . 2 i n a m p l i f i e r p o s i t i o n , t h e s i g n a l i s t h e n
f e d t o t h e p o w e r o u t p u t a m p l i f i e r c h . 2 . T h e p r o -
g r a m m e w i l l b e r e p r o d u c e d t h r o u g h b o t h i n t e r n a l
s p e a k e r s , a n d t h r o u g h b o t h p r e - a m p o u t p u t f e r m i -
n a t s .
T h e p r o c e d u r e f o r p l a y b a c k f r o m c h . 2 i s e x a c t l y t h e
s a m e a s e x p l a i n e d a b o v e e x c e p t t h a t t h e f u n c i i o n
s e l e c t o r s w i t c h c h . I i s s e t t o A M P p o s i t i o n a n d f u n c -
tion selector switch ch. 2 is set to oosition PLAYBACK.
5.2.7 Stereo playback
R e f . b l o c k d i a g r a m f i g . 3 9 .
B o t h f u n c t i o n s e l e c t o r s w i t c h e s ( c h . I a n d c h . 2 ) a r e
set to position PLAYBACK and the speaker switch is
sef to position lNT. The connection between the out-
p u t s o f t h e r e c o r d p r e - a m p l i f i e r s i s d i s c o n n e c t e d .
T h e s i g n a l s w i l l p a s s e a c h p l a y b a c k p r e - a m p l i f i e r ,
p l a y b a c k e q u a l i z i n g a m p l i f i e r a n d p o w e r o u t p u t
a m p l i f i e r . T h e s t e r e o p r o g r a m m e w i l l b e p l a y e d b a c k
t h r o u g h b o t h i n t e r n a l s p e a k e r s a n d t h r o u g h b o i h p r e -
a m p o u t p u t t e r m i n a l s .
5.2.8 Stereo amplifier
R e f . b l o c k d i a g r a m f i g . 3 9 .
T h e f u n c t i o n s e l e c t o r s w i t c h e s c h . i a n d c h . 2 a r e s e t
to position AMP. The signals pass each record pre-
a m p l i f i e r , e q u a l i z i n g a m p l i f i e r a n d p o w e r o u t p u l
a m p l i f i e r . T h e s i g n a l s a r e t h e n f e d t o t h e s p e a k e r s .
The connection between the outpuis from the equal-
i z i n g a m p l i f i e r s i s d i s c o n n e c t e d . T h e o u t p u t g a i n i s
c o n t r o l l e d b y t h e v o l u m e c o n t r o l s ( u p p e r k n o b c h . l ,
l o w e r k n o b c h . 2 ) .
5.2.9 Add a lrack
R e f . b l o c k d i a g r a m f i g . 3 9 .
T h e " a d d a t r a c k " r e c o r d i n g i s a t e c h n i q u e o f p l a y i n g
b a c k a p r e - r e c o r d e d p r o g r a m m e f r o m o n e c h a n n e l ,
a n d r e c o r d a n o l h e r p r o g r a m m e o n t h e o t h e r c h a n n e l
a t t h e s a m e t i m e . B o t h p r o g r a m m e s w i l l b e h e a r d
s i m u l t a n e o u s l y w h e n t h e t a p e i s p l a y e d b a c k i n
stereo. We presume that the pre-recorded programme
is recorded on ch. l The function selector switch
c h . I i s s e t t o p o s i t i o n P L A Y B A C K , a n d t h e s p e a k e r
s e l e c t o r s w i t c h i s s e t t o p o s i t i o n l N T . T h e s i g n a l w i l l
p a s s t h e p l a y b a c k p r e - a m p l i f i e r , t h e p l a y b a c k e q u a l -
i z i n g a m p l i f i e r a n d t h e p o w e r o u f p u t a m p l i f i e r a n d
f e d t o t h e i n t e r n a l s p e a k e r c h . l . T h e p l a y b a c k
e q u a l i z i n g a m p l i f i e r i s o p e r a t i v e . T h e r e c o r d i n g i s
m a d e o n c h . 2 a n d t h e r e c o r d i n g s i g n a l m a y b e c o n -
n e c t e d t o e i t h e r o f t h e i n p u t t e r m i n a l s c h . 1 , c h . 2 o r
b o i h .
The function selector switch ch. 2 is sef to RECORD
position. The outputs from the record pre-amplifiers
are connected and the signal passes the record
e q u a l i z i n g a m p l i f i e r a n d i s f e d t o t h e r e c o r d h e a d
c h . 2 .
T h e r e c o r d i n g s i g n a l i s m o n i t o r e d t h r o u g h t h e i n t e r -
n a l s p e a k e r c h . 2 w i t h a r e d u c e d o u t p u t .
The "add a frack" recording used for
language teaching
L a n g u a g e t e a c h i n g i s a t y p i c a l e x a m p l e o f t h e u s e o f
"add a track" recording, the lesson (master track) is
p r e r e c o r d e d o n t h e t a p e a n d t h e s t u d e n t c a n p l a y -
b a c k , l i s t e n t o t h e l e s s o n , m o n i t o r a n d r e c o r d h i s o w n
exercises. The playback must be in stereo, and the
33