Dynavector DV-505 User manual

Dynavector DV-505 Tone arm Instruction Manual
INDEX
Dynavector DV-505 tone arm has an entirely
new concept in tone arm design. The DV-505
is a high performance tone arm with various
new functions that make the cartridge in use
work the best way it can. The DV-505 user is
requested to please read through this
brochure to enjoy its niceties fully.
1. Foreword
2. Parts illustration
3. Pre use check points
4. Application(1)
5. Application(2)
6. Arm resonance
7. Two dampers
8. Specifications
discontinued
1. Foreword
As is commonly known, a pickup cartridge generates electricity by cantilever motion relative to motion of
cartridge proper. While cantilever stylus precisely traces signals recorded in groove of disk, cartridge proper
receives those signals faithfully provided that it is held motionless (free of vibration). Hence, the great role of
a tone arm.
How should cartridge be held motionless without adverse effects on signal trackability? The DV-505 has
solved this problem by adopting the unique (vertical/horizontal) Bi-axis system. The horizontally movable
main arm is of sufficient weight for vibration-free operation, and the adverse effect of weight on signal
trackability is nullified by use of an angular-radial compound bearing design. Conversely, the vertically
movable sub-arm is made so light that it never lets the stylus jump the groove of even a disk with warp(s)
previously unnegotiable.
Also, the DV-505 employs a double damper method -- inertia controlled dynamic damping type plus electro-
magnetic damping type -- to introduce an ideal solution to the problem of tone arm resonance in low
frequency range. This has generally been neglected about audio equipment that absolutely requires a flat
frequency characteristic.
2. Parts illustration

3. Pre use check points
The DV-505 leaves factory only after fine adjustment and meticulous check. But unexpectable incidents in
transit can possibly change its condition.
To use the DV-505 in its best condition, the user is requested to check the following points prior to
application:
●Isn't damper plate in contact with magnet?
Pick up main arm and gently reciprocate it sideways. If
damper plate is free from bent (or distortion) and clear
of magnet, main arm can be thus moved smoothly.
Otherwise, metallic frictional sound occurs and, as this
motion is forced, it encounters growing resistance. In
such a case, confirm direction in which damper plate is
bent and apply finger pressure to put it into right and
straight shape. (This copper plate can be deformed with
ease. After its adjustment, it must not be touched by
hand or hit by foreign object.)

●Is inertia controlled dynamic damper functioning?
Pick up main arm gently and look in from below.
Normally, damper weight is seen vibrating finely. If it is
in contact with arm's inner surface and is not so
vibrating, Loosen stopper and, with light downward pull,
refasten it, and/or straighten springboard.
4. Application (1)
Output cord fixing
As illustrated connect output cord connector (accessory
attachment) securely to output terminal plug below arm.
Even when this is complete, connector leaves plug stem
uncovered for 5mm, which is so designed to be
compatible also with other output cords sold generally on
the market.
Headshell/cartridge fixing
Fix cartridge to shell (for temporary purpose), insert
template between arm and shell, and lock shell. Then
where stylus points exactly at special mark on template, fix
cartridge securely to shell.
Do not remove template yet because it will also be used,
the way it is, for positioning arm.
(Stylus position so determined allows for template
thickness. When template is removed and shell finally
locked completely, stylus finds itself in right position.)

Base fixing to player board
The DV-505 can be fixed to player board simply by nailing
its unit base plate with four wood screws provided to each
unit.
Relax slide stopper and turn slide knob to lift main arm to
a height where cartridge stylus won't scratch turntable.
Then move arm base to where turntable spindle smoothly
fits in with spindle hole in template.
When spindle and hole so fit, and at the same time main
arm is situated right above arm rest, part of base plate not
overshadowed (overlapped) by turntable (see illustration)
is available for screw drive-through.
Base position so determined, drill convenient screw holes
in player board and fix base plate onto it with wood screws
(supplied).
* In case that player board has not insulator, or if the user
wants to set the DV-505 without fixing to player board. Put
the rubber sheet (supplied) under the base plate. (At usual
conditions of use, this is not necessary.)
Arm height adjusting
With slide stopper relaxed, height of arm can be adjusted
by turning slide knob. But as arm slowly sinks by itself
when slide stopper is loosened, an easy way to adjust arm
height is, first lift arm to maximum height, then let arm sink
while holding stopper between fingers, and finally fasten
stopper just when arm comes down to right place.
Arm must be just so high that sub arm may precisely
parallel record disk surface.

Arm balancing
●Horizontal balancing
Main arm is designed to maintain itself always level.
But horizontal balancing is still necessary to
distribute bearing load evenly and thereby realize
best trackability. To achieve this balance, shell and
sub weight alone normally suffice. First position sub
weight A closest to the fore, or sub weight B at
white-color balancing point mark, and then slide
sub weight on scaled bar by one notch backward
per every 5g added to cartridge weight. (In using
any shell other than one supplied, add to or deduct
from cartridge weight the difference in weight
between these two shells.)
●Lateral balancing
If arm flows laterally to either side while inside force
canceller weight is suspended from zero point or is
removed from cartridge, slide lateral balancer to
either side to prevent arm from flowing so. (Make
sure beforehand that arm base is set level.)
Tracking force adjusting
First set tracking force adjuster to zero point and balance
sub arm precisely level by sliding sub-weight to right
position. Sub arm so balanced, turn adjuster finger screw
to obtain necessary tracking force. Adjuster scale is
graduated by 0.25g and between graduation marks, too,
adjustment is done progressively in proportion to adjuster
screw advance.
Choose sub weight A or B according to guide table to the
left. Protruding in hole in sub weight is a pin to stop sub
weight from pivoting on scaled bar. Mount sub-weight onto
bar with this pin pressed with screwdriver, etc.

Inside force canceller
To suspend inside force canceller weight from weight
scale bar, do it exactly from graduation mark equal to
tracking force selected.
When the DV-505 tone arm is moved up (and down)
before and after record playing, main arm as a whole is
designed to be elevated. But user is requested not to lift it
excessively or with abrupt force.
5. Application (2)
Player equipped with cover
Player may have its cover. Because the DV-505 output service
cord is not led out through player board, cover won't close neatly.
In such a case, make a hole (21mm - 25mm in diameter) at a
convenient place in player board, fit accessory bushing to hole so
made, and run output cord through it.

Arm base posture adjusting
In case that player board fails to provide sufficient space for arm
base, loosen screws on backside of base and change direction of
arm stand.
To carry DV-505 around
Stand top cover is screwed into stand. Replace it with accessory
carrying handle.
The DV-505 unit can then be carried around as illustrated.
To replace output terminal
Cord connector can be removed in the following manner, either for
replacement with another kind of connector or for complete
removal to eliminate needless contact resistance:
1. Link connector of accessory output service cord to output
plug;
2. Remove fastener screw (with screwdriver);
3. Pull cord gently, and output terminal is removed from cord ;
4. Wiring colors mean:
red -Right channel hot
white -Left channel hot
green -Right channel ground
blue -Left channel ground
(Fastener screw also serves as unit connection to earth.)

6. Arm resonance in low frequency range
Illustration shows spring in suspension from overhang and
weight slung from it. When pulled down and then
released, spring weight combination will reciprocate
longitudinally at a certain frequency. This is generally
called spring mass oscillation system. Oscillation of two
units of mass at a common fixed frequency is called
resonance. This frequency ('f') Is mathematically
expressed
Where 'c' is system compliance in cm/dyne and 'm' stands
for mass of system.
Similar phenomenon is observed in arm-cartridge
assembly as it reproduces sound from record disk.
Graphically, cartridge compliance may be likened to
spring, and arm pivot to weight.
This is what is called arm resonance in low frequency
area, and there are as many resonance sources as there
are pivoting gadgets in tone arm.
At such a frequency of resonance arm becomes very
sensitive to vibration and, even when frequencies of 'flat'
characteristics are reproduced from record, arm
resonance causes larger output than true to record or
'peak' phases (See diagram 3). At frequencies higher than
arm resonance, arm does not so vibrate at all, and
cantilever oscillation alone translates into output. But at
frequencies lower than that, cantilever and arm oscillate
together and fail to generate electricity. This is why arm
resonance frequency 'fo' is called low sound reproduction
margin.
With conventional type tone arms vertical and horizontal pivots are placed in close proximity. This causes
these two resonance sources to vibrate at the same frequency, as if vibrating as a unit. Peaks then become
larger and so much harder to damp.

The Bi-axis type DV-505 separates one pivot remotely
from the other. It thus encounters two peaks
simultaneously, but each peak is smaller than the two put
together, and horizontal resonance peak is effectively cut
by a couple of unique dampers (See diagram 4), for the
following reason :
So-called '45-45' record groove cutting method which is presently in use, does horizontal cutting at same
phases of input signal and vertical cutting at inverse phases. Because sub-100Hz wave lengths elongate for
more than several meters, stereo recording of low sounds produces, almost comprehensively, same phase
signals for both right- and left-hand side channels and, naturally, signals for horizontal cutting come
excessively to the fore. Then considering disk structure, it Is not possible to impress on it deep-going low
frequency signals.
The DV-505 has solved just that. By reducing peaks over all, it adds to low frequency area stability. Also, it
faithfully tracks surfaces so warped that no other tone arms could negotiate well, and thereby limits effect of
such warped disks on sound reproduction. The DV-505 an out performer.
7. Two dampers
As explained in part 7, DV-505 employs two kinds of damper- - electro magnetic and inertia-controlled type.
●electro magnetic damper
This damper applies effect of eddy current, which is generated when conductor moves in magnetic
field, and which obstructs conductor in motion. It has almost no damping effect on motion of non-
vibrating tone arm, but is highly effective to vibration of arm, such as arm resonance.
●Inertia controlled dynamic damper
This damper, incorporated into main arm, consists of a pair of spring and mass, each of these
constituents having a carefully selected constant. This spring mass oscillation system oscillates only
horizontally as main arm resonance occurs, and causes resonance peak to dip.
Phase lag in one oscillation system relative to another is effectively applied in this damper, which
functions only in response to arm resonance.
8. Specifications
System Bi-axls inertia controlled dynamic balance type tone arm
Total length 335mm (including shell)

Effective length 241 mm
Overhang 15mm
Offset angle 21.5 degree
Height 72mm (liftable to max. 94mm )
Height adjustability 37-70mm (at sub arm center)
Optimum cartridge weight 0 - 23grams (or up to 35g including headshell)
Tracklng force adjustability 0 - 3grams by 0.25grams step
Lateral tracking angle error -1.1 degree to +2.2 degree
(0 degree at inner band of record disk, 2.2 degree at outside)
Motion sensitivity Lateral -- less than 50mgrams
Vertical -- less than 50mgrams
Net weight 1,250 grams
Output connector 5P connector with low resistance cord 0.025ohms/m , 37pF/m
Head connector: EIA standards
Head shell Aluminum headshell
(December/3/2001)
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