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Case B: front panel for stereo 80 A AFU only but will accept other
c o m b i n a t i o n s a s c a s e A .
Case C: front panel for tuner and decoder only, room for PZ1 or PZ6.
West Hyde can supply a transformer for the PZ8 and all hardware
f o r t h e a m p l i f i e r c a s e s , w h i c h w i l l b e r e a d y p u n c h e d .
H o l e s i n d i c a t e d $ s h o u l d b e % " ( 3 m m ) d i a m e t e r . T h e l a r g e h o l e
o n t h e s w i t c h u n i t s h o u l d b e 7 o " ( 6 m m ) a n d a l l o t h e r h o l e s * "
( 5 m m ) . S e e p a g e 3 1 f o r t e m p l a t e s
A3
Positioning the modules
A3.1. Preamp and AFU, tuner and decoder
The positioning of these will naturally be determined by the cabinet
w h i c h i s c h o s e n .
The Stereo 80 is the module which is most used and is the heart of
the system so this will probably be placed centrally, with the other
m o d u l e s a r o u n d i t . ( e . g . t u n e r a n d d e c o d e r t o t h e l e f t , A F U i o t h e
r i g h t ) .
Remember that the input wires to these modules are sensitive to
induced hum so do not place them where these wires will pass near
t o m a i n s t r a n s f o r m e r a n d w i r i n g , o r t o t u r n t a b l e m o t o r s , o r n e a r t h e
outputs of the 240/760.
I n o u r l a y o u t s ( A B A A C ) w e k e e p a l l m a i n s w i r i n g i n t h e b a c k
right (or left) hand corner well away from the preamp.
43.2.Z|0 and 260
The two power amplifiers should be positioned close to each other
(two can even share the same heatsink block as shown in section
D 8 9 . 2 . 2 . 1 . K e e p t h e m a w a y f r o m t h e i n p u t s o c k e t s , w i r i n g a n d
connections to the preamplif ier, to avoid interaction.
A3.3. Earth point
A point should be chosen mid-way between the 240's or 260's to
w h i c h a l l e a r t h w i r e s a r e r u n , s e p a r a t e l y . P o s i t i o n t h i s s o t h a t w i r e s
t o t e r m i n a l s 1 a n d 2 ( a n d 3 o n 2 6 0 ) o f t h e a m p l i f i e r s a r e n o l o n g e r
t h a n 3 " . S e p a r a t e w i r e s a r e a l s o r u n t o t h e e a r t h p o i n t f r o m :
power suppry -ve
speaker sockets
mains earth
A F U e a r t h
P r e a m p l i f i e r e a r t h
D o n o t
' d o u b l e
u p ' o n a n y o f t h e s e w i r e s .
I t i s u s u a l l y c o n v e n i e n t t o f o r m t h i s p o i n t f r o m s e v e r a l s o l d e r t a g s , a s
we have, which are screwed down to the chassis for support (and
t o m a k e e l e c t r i c a l c o n n e c t i o n t o t h e c h a s s i s ) . l t d o e s n o t h a v e t o b e
screwed down but, if it is not, a separate wire should be connected
f r o m i t t o t h e c h a s s i s ( o r m e t a l e a r t h i n g f o i l ) .
Note in layout AC we have run a separate wire to earth the metal
heat fins of the Z40s -
this of course is not necessary if a metal
c h a s s i s i s u s e d s i n c e e a r t h i n g w i l l t h e n b e d o n e a u t o m a t i c a l l y
t h r o u g h t h e m o u n t i n g .
A.3.4. Power supply
The P25,6 or 8 will be mounted near to the Z40s or Z60s so that the
positive and negative wires are not longer than about 6". This length
i s l e s s c r i t i c a l w i t h t h e P Z S a n d m o r e w i t h t h e P Z B . I n o u r l a y o u t A C
these wires are about 12" long, which is satisfactory with PZ5.
The PZS or 6 will also require positioning so that the transformer is
k e p t a w a y f r o m i n p u t a n d o t h e r w i r i n g ( o r i t c a n i n d u c e h u m ) a n d s o
t h a t m a i n s w i r e s a n d c o n n e c t i o n s a r e n e a t a n d t o g e t h e r .
The PZ8 is not so critical - the transformer can be mounted some
distance from the PZ8 (there are no mains connections on the PZ8
itself ).
lf the + ve and -ve wires f rom the power supply are too long it can
cause distortion. lf this occurs then a second point can be chosen,
similar to the earth ooint but isolated f rom the chassis. A 1 000u F 50V
capacitor should be connected between this H.T. point and the earth
p o i n t , a n d a l l H . T . w i r e s a r e n o w r u n t o t h e H . T . p o i n t i n s t e a d o f
direct to the power supply which now connects through a single,
i o n g e r w i r e t o r v € H . T . p o i n t .
A3.5. Mains wires
Mains wiring is potentially dangerous. lt has 250V present and if by
accident this is applied anywhere other than the correct terminals on
the power supply it will be destructive.
Mains Live (Brown) connects direct to the fuse: the other connect-
ion of the fuse goes through one pole of the on,/off switch to the L
1 0
connection on the PZ5 or 6 or to the 240 volt input on the PZ8
t r a n s f o r m e r .
Mains Neutral connects through the second pole on the switch to N
on the PZ5,/6 or to Ov on the transformer primary of the PZ8.
Mains earth (green/yellow) connects direct to the main earth point
i n t h e a m p l i f i e r . l f a t u r n t a b l e o r o t h e r m a i n s p o w e r e d i t e m i s t o b e
used, operated by the same switch as the Project 80, then the mains
w i r e s h o u l d b e t a k e n f r o m L a n d N o n t h e P Z S / 6 v i a a s u i t a b l e p l u g
a n d s o c k e t i f r e q u i r e d . t o i t s m a i n s c o n n e c t i o n .
O N N O A C C O U N T M U S T A N Y M A I N S C O N N E C T I O N B E M A D E
T O A N Y O T H E R M O D U L E
B e c a u s e o f t h e h i g h v o l t a g e , a n d t h e p o s s i b i l i t y o f i n d u c i n g h u m ,
mains wiring is best kept well away from the rest of the amplifier.
Care must be taken if the mains switch is to be mounted on the front
of the amplifier. see also section A5.3.
43.6. Output wiring
From pin 9 on the 240 orZ60 the output wire corrnects (via a 2000uF
c a p a c i t o r o n t h e 2 6 0 o n l y ) t o t h e o u t p u t s o c k e t , a n d t o a n y
headphone sockets you may have fitted.
l f a n y o f t h i s w i r i n g i s a n y w h e r e n e a r t h e i n p u t w i r i n g o f t h e
p r e a m p l i f i e r , o r a n y o t h e r m o d u l e s , i n t e r a c t i o n c a n o c c u r a s s o m e o f
t h e o u t p u t s i g n a l w i l l t h e n f e e d b a c k t o t h e i n p u t . K e e p o u t p u t w e l l
a w a y f r o m t h e i n p u t a n d a l s o t w i s t t h e o u t p u t e a r t h a n d l i v e l e a d s
together.
A3.7. Input wiring
S h o u i d u s u a l l y b e s c r e e n e d - b u t i f i t i s s h o r t ( 4 " o r s o ) a n d d o e s
n o t p a s s n e a r a n y m a i n s o r o u t p u t w i r i n g , s c r e e n i n g i s n o t n e c e s s a r y .
T h u s , i n o u r p l i n t h l a y o u t w e h a v e n o t u s e d s c r e e n e d w i r e s f r o m t h e
tuner to the Stereo 80, but we have used screened wire from the
p i c k u p .
A4
Use of other modules in our layouts
44.1 740 or Z.60
T h e 2 6 0 i s l o n g e r t h a n t h e 2 4 0 . l t a l s o r e q u i r e s a n a d d i t i o n a l f a i r l y
b u l k y o u t p u t c a p a c i t o r ( s e e s e c t i o n D . 5 ) . T h e o u t p u t c a p a c i t o r i s
p a r t o f t h e o u t p u t w i r i n g a n d m u s t b e t r e a t e d a c c o r d i n g l y .
It should be noted that there is no advantage in using the 260
i n s t e a d o f t h e 2 4 0 u n l e s s a P Z 8 i s u s e d , a l t h o u g h w i t h l 5 O s p e a k e r s
and a PZ6, the supply voltage can be increased to about 40 to give a
useful power increase.
A4.2. PZ5 or 6
T h e s e a r e p h y s i c a l l y a n d e l e c t r o n i c a l l y i n t e r c h a n g e a b l e . H o w e v e r ,
w h e n u s i n g a P Z 6 , a d d i t i o n a l h e a t s i n k i n g w i l l b e r e q u i r e d ( s e e s e c t i o n
D 6 . 4 . ) . T h e P Z 6 w i l l r e s u l t i n a s l i g h t i m p r o v e m e n r i n h u m l e v e l w h e n
t h e t u n e r i s u s e d .
A4.3. PZ8
The PZ8 is not physically or electrically a replacement for the PZs or
6 and the transformers commonly available for the PZ8 are large
( a b o u t 1 0 x 8 x B c m ) . l f t h e t r a n s f o r m e r i s t o b e h o u s e d i n t h e s a m e
case then this will need to be considerably larger than the PZ5l6
case. The PZ8 must not be used with Z40s unless its output voltage
is reduced {see section EC6) but if this is done it does result in a
considerable improvement in performance.
T h e P Z 8 a l s o s h o u l d b e c h o s e n w h e r e s u s t a i n e d h i g h p o w e r
o p e r a t i o n i s r e q u i r e d . P Z S a n d 6 a r e s m a l l a n d a f t e r a w h i l e g e t q u i t e
hot at higher powers. lt is, of course, quite possible to mount the
PZ8's transformer remote from the PZB proper.
A4.4. Project 60 modules
The earlier project 60 modules are compatible with project 80 except
that the Stereo 60 gives more output then the project 80 preamplifier
so the gain of the 230 and 250 is less than that of the 240 and 260.
However, the gain of the 260 has been kept deliberately low so that
it is still compatible with the earlier Project 60.
When using project 80 control modules with 230 or 250 the gain of
the 230 or 50 will need to be increased.
A4.s. tcl2
l t i s p o s s i b l e t o u s e a n l C 1 2 i n s t e a d o t a 2 4 0 . T h e l C 1 2 s h o u l d h a v e
i t s g a i n s e t t o 1 0 0 a s e x p l a i n e d i n t h e i n s t r u c t i o n s .
A4.6. Other Modules
There are other makes of modules available and it is orobable that
most of these will present no problem when used with Project 80
provided they use a similar power supply voltage and have a
negative earth. Such combinations, however, are beyond Sinclair's
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