this DV505 brochure

Dynavector
DV
505
BI-AXIS
INERTIA CONTROLLED
DYNAMIC
BALANCE TYPE
TONE ARM
A n Entirely New Concept
in Tone A r m Design
In a r a d i c a l departure f r o m c o n v e n t i o n a l l y
a c c e p t e d w a y s of tone a r m d e s i g n , O n l i f e
R e s e a r c h i n t r o d u c e s its D y n a v e c t o r D V - 5 0 5
a r m that looks and in many ways behaves like
no o t h e r t o n e a r m ever before. B y its full t e c h ­
n i c a l d e s i g n a t i o n it is c a l l e d a " m a g n e t i c a l l y
damped, inertia controlled, bi-axis massdivided, d u a l pivot, d y n a m i c a l l y balanced
tone a r m , " a lengthy description whose nu­
m e r o u s u n f a m i l i a r t e r m s a l r e a d y h i n t at the
u n i q u e n e s s of this i n n o v a t i v e d e s i g n .
D e t a i l s a b o u t features a n d functions are
e x p l a i n e d o n the b a c k page; the v a l i d i t y of
the v a r i o u s design i n n o v a t i o n s w i l l be
d e m o n s t r a t e d best, h o w e v e r , i n a careful
c o m p a r a t i v e l i s t e n i n g test i n c o n j u n c t i o n
w i t h a h i g h fidelity r e p r o d u c t i o n s y s t e m
of the h i g h e s t order of p r o f e s s i o n a l
quality.
Dynavector Systems. Ltd
Dynavector
BI-AXIS INERTIA CONTROLLED
DYNAMIC BALANCE TYPE
TONE A R M
DV 5 0 5
T h e D y n a v e c t o r D V - 5 0 5 R a i s e s T r a c i n g Fidelity
to A N e w
Level of A c c u r a c y .
A t o n e a r m has to s u p p o r t a n d g u i d e the p h o n o car­
tridge in its p a t h a l o n g the r e c o r d g r o o v e , p e r m i t t i n g it to
faithfully f o l l o w all g r o o v e e x c u r s i o n s at a light t r a c k i n g
force, w i t h o u t h o w e v e r v i b r a t i n g , r e s o n a t i n g or in a n y
other way
m o v i n g itself. C o n t r a r y to
conventional
t h i n k i n g , this " s t e a d i n e s s " in a t o n e a r m is best a c h i e v e d
by g i v i n g the a r m a r e l a t i v e l y h i g h m e c h a n i c a l m a s s .
R e c o r d s , h o w e v e r , being mass p r o d u c e d , almost in­
v a r i a b l y s h o w s o m e s m a l l d e g r e e of w a r p w h i c h forces
the a r m u p a n d d o w n w h e n p l a y i n g . A n a r m of large
m a s s w o u l d , b e c a u s e of its h i g h inertia, c a u s e r a t h e r
v i o l e n t c h a n g e s in t r a c k i n g force.
Ideally a t o n e a r m s h o u l d fulfill t w o conflicting d e m a n d s :
large m a s s for steadiness in the h o r i z o n t a l p l a n e , l o w
m a s s for the v e r t i c a l p l a n e . A t o n e a r m s h o u l d a c t u a l l y
be t w o t o n e a r m s . I m p o s s i b l e ?
T h e Dual-Pivot D y n a m i c Balance Dynavector A r m
T h e D y n a v e c t o r D V - 5 0 5 is t w o a r m s i n o n e . Its m a i n a r m sec­
t i o n of large m a s s , p i v o t e d to m o v e o n l y i n the h o r i z o n t a l p l a n e ,
p r o v i d e s a s u p e r b d e g r e e of steadiness; its s u b s e c t i o n ,
s e p a r a t e l y p i v o t e d to m o v e o n l y v e r t i c a l l y , is of l o w mass, a n d
t r a c k i n g f o r c e is a p p l i e d b y a p r e c i s i o n c a l i b r a t e d s p r i n g
m e c h a n i s m . It t h u s p r o v i d e s perfect t r a c k i n g of lateral a n d ver­
tical g r o o v e m o d u l a t i o n s w i t h o u t b e i n g affected b y r e c o r d w a r p .
Dynamic D a m p i n g System
Eliminates A r m Resonance
E v e r y t o n e a r m , b e i n g a p h y s i c a l mass, t e n d s to r e s o n a t e at or
a r o u n d a c e r t a i n f r e q u e n c y , a n d this a r m r e s o n a n c e c a n
s e r i o u s l y affect the cartridge's t r a c k i n g fidelity — t h e s o u n d
b e c o m e s " m u d d i e d " a n d loses all t r a n s p a r e n c y a n d clarity.
R e s o n a n c e s i n c o n v e n t i o n a l t o n e a r m s h a v e n o t really b e e n
e l i m i n a t e d but o n l y m o v e d d o w n into the s u b s o n i c r e g i o n at
a r o u n d 1 0 t o 2 0 H z w h e r e t h e y s h o w u p as a s t r o n g p e a k — u p
to l O d B — i n t h e s y s t e m f r e q u e n c y r e s p o n s e c u r v e .
T o s o l v e this p r o b l e m i n the D y n a v e c t o r D V - 5 0 5 , a s u b s i d i a r y
v i b r a t i n g m a s s c o n s i s t i n g of a s p r i n g b o b w e i g h t is p r o v i d e d i n ­
s i d e the U - s h a p e d m a i n a r m , w i t h its m a s s c a l c u l a t e d p r e c i s e l y
in s u c h a w a y that it will r e s o n a t e at the s a m e f r e q u e n c y — but
in e x a c t l y o p p o s i t e p h a s e — as the a r m itself. T h i s o p p o s i t e
r e s o n a n c e has t h e effect of c a n c e l l i n g o u t a n y a r m r e s o n a n c e .
Constant, U n v a r y i n g
Tracking Force
Specifications
3 3 5 m m (incl. h e a d
L e n g t h , o v e r all
V e r t i c a l t r a c k i n g force is a p p l i e d b y
a precision m a d e spiral spring
device. This " d y n a m i c balance"
s y s t e m m a i n t a i n s u n v a r y i n g track­
ing force r e g a r d l e s s of r e c o r d w a r p .
T r a c k i n g force a d j u s t m e n t is d o n e
by m e a n s of a d i a l m o u n t e d o n the
sub a r m pivot.
Electro-Magnetic Damping System
for Perfect T r a c k i n g
shell)
241mm
Effective length
Height
normal
72mm
max.
94mm
Offset angle
21.5°
Lateral tracking
At inner grooves: 0
error
A t outer grooves:2.2 °
Overhang
15mm
0
Adjustable height
A n a d d i t i o n a l m e a s u r e o f d a m p i n g is effected b y t h e electro­
m a g n e t i c d a m p i n g s y s t e m . A c u r v e d r o d a t t a c h e d t o the r e a r of
the a r m is e m b e d d e d i n a m a g n e t i c field s u p p l i e d b y t w o per­
m a n e n t m a g n e t s . A n y m i n u t e m o v e m e n t of the r o d , d u e to a n
u n d a m p e d a r m r e s o n a n c e , c a u s e s a n e d d y c u r r e n t t o be i n ­
d u c e d i n the r o d , w h i c h i n t u r n interacts w i t h the m a g n e t i c field
to r e t u r n t h e s y s t e m to its rest state. A s r e s p o n s e g r a p h s s h o w ,
the a r m t h u s b e c o m e s v i r t u a l l y free f r o m a n y
resonance
p h e n o m e n o n a n d p e r m i t s perfect t r a c k i n g of e v e n s u b s o n i c
f r e q u e n c i e s . T h i s h i g h l y effective d a m p i n g a l s o m a k e s the a r m
i m p e r v i o u s to a c o u s t i c f e e d b a c k a n d v i b r a t i o n s t r a n s m i t t e d
t h r o u g h the f l o o r a n d turntable cabinet, to g u a r a n t e e u t m o s t
clarity of s o u n d u n d e r all o p e r a t i n g c o n d i t i o n s .
Free-standing T y p e >
T h a n k s t o its h e a v y base, t h e
D y n a v e c t o r a r m c a n be p l a c e d
freely o n a n y turntable w i t h o u t
requiring screw mounting. (Moun­
ting h o l e s are, h o w e v e r , p r o v i d e d . )
A t e m p l a t e is s u p p l i e d for c o r r e c t
o v e r h a n g adjustment.
range
38-70mm
Suitable cartridge
9 - 3 5 g r a m s (incl. h e a d
weight
shell)
Lateral & vertical
sensitivity
Less than 5 0 m g
P h o n o cable
L o w capacitance type
(less t h a n 3 7 p F / m ) ,
5-pole connector,
l e n g t h 1.2 m
H e a d shell
Standard E I A type
connection
4-pole connection
AUTHORIZED DISTRIBUTOR OR DEALER
Dynavector Systems. Ltd
Acousta G i n z a 8-6,Ginza 3-chome C h u o - k u , T O K Y O
104 J A P A N
T e l e p h o n e : T o k y o (564)
Telex: J 2 3 4 7 5
Dynavec
4011
C-d-101
709
20,000
I