Nad Cartridge Owners Manual

Page 1

5120
DVA TUNING DATA FOR POPULAR CARTRIDGES

The table (page 2) lists many at the phone pickup cartridges on the world market.
with relerence data tor tuning the DVA (dynamic vibration absorber) in the Ilexible
mu: tonearm, This table will be updated periodically as more inlormation is obtained
lDl' existing cartridge models. and as manulactures introduce new pictiup cartridges,

For each cartridge the table provides suggested settings or the resonance lrequency
in) and the damping tot oi the dynamic vibration absorber. These have eeen
computed using the nominal values oi pickup body weight into) and stylus
compliance (03) listed in the table,

it your cartridge is listed in the table, the suggested DVA settings will provide very
nearly optimum oerlormance with the unique flexible NAD tonearm.lt is not necessary
to be very exacting when maliino the adiustments. a variation oi :2 Hz in resonance
lreouency (Fr) or at in the damping value to) will yield only a small dillerence in
system perlormance.

The suggested values in the table are only approximate, because various samples 0!
the same cartridge model may ditler slightly in compliance For this reason the
resonance lrequsncy may vary by one or two Hz trom sample to sample It you wish to
obtain exactly optimum DVA tuning tor your particularcartridge. you may use the
NAD lest record to determine the resonance lreguency by direct experiment, as
described in Appendix B or the instruction manuai lor the NAD 5120 turntable.

it your cartridge is not listed in the table, you may try any otihe lollowing
approaches lor tuning the DVA:

i1) Adopt median settings (Fr:10 Hz and 0:2) Even it these are not optimum, they
will provide better perlormance than a tonearm that lactis the DVA reature.

(2) Contact your NAD dealer to discover whether there may be an updated version
or this table that contains suggested DVA settings tor your cartridge

(3) Use the graphs below to determine approximate settings or the resonance
lreouency and damping

(at Obtaln the NAD test record and determine the optimum DVA settings by direct
experiment.

USING THE GRAPH!

II the Clrlridge weight (MD) and the stylus compliance (Cl) Ira known. the resomnl
trequerlcy (Fr) clrl DB computed, This rclltionchip I: shown in tho first graph. To 0
the grnph. first locate the net weight 0' "ll cartridge body art the horizontal axis. From
that paint draw a vertical line upward until ll intersects the curve that represents the
compillnce (Cs) ol the Stylus lsembly. From there. draw I horizontal line to th. lofl
until it interlects thn resonance trequency (Fri scale along the tan edge or the graph.
The graph illustrates this process tor a cartridge having a weight or 5.7 grams and I
compliance or 20; the resulting radon-lice trequancy is 9.5 Hz.

You need to know Mp and CI in order to an thll graph. The weight of the cartridge
body usually is Includad among the tpoclliutiona or the plckup cartridge. or it can be

measured directly, The dynamic complilnca usually I: not specified (II it is spectliod.

it may have been measured at mid-rrequarlcios; the compliance It lntraaonic
lrequenciel may only be two-thirds or the Ipdciliad value) The low-
rrequsncy complilnce is sometimes flivlrl in I031 "ports. notably in "Hi-Fl Choice"
(England) and HI-Fl Sleraophonic" (Germany).

in any case, the VT? provide: an cpproxtmlte guide to the compliance It the
optimum VTF is over 2 gram: th. compliance is likely to be relatively low (around 2)
it the correct VTF is npprcximllcly La gums. the cartridge probably has I medium
Compliflncl (lround 20). IV the VTF is only 1.2 gums, the compliance is high (above

RESONANCE FREQUENCY (Fr)

L OD VS

US CD PLIANCE

14
13
12
11
10 (FT=9
9

8
7
G

RESONANCE FREQUENCY Fr [H1]

F ,5. I)

23456159101112

0 1
PHONO CARTRIDGE MASS up (GRAMS)

301. Using these estimates you can use the graph to compute Fr, Though only
approximate. the result will be accurate enough (within 2H2i l0 obtain must at the
beneltl DI the DVA.

Damping. The second grsph provides a means at estimating the optimum setting or
the damping rod, To use It. first note your cartridge weight. Subltlct Illl VTF Ihlt you
are using, and locate the resulting number on the horizontal 1in or the graph, Duty 3
venical line upwnrd tram there untll it lntersacls the curve that "prawn the
resort-nut frequency that you have tuned the DVA to. From that point. draw I
horizontll line to the Ielt until it intersects the damping scale nlong tho left edge at tha
graph,

The graph illustrates the process for a cartridge that weighs 5.7 gums and ill Us!
with a VTF or 2.0 grams. The vnrtical line is drawn It 3.7 grlms. The relonanoe
trequency was determined (in the lirst graph, or by direct mauuremvnt tiling the NAD
test record) to be 9.5 Hz. 50 we draw the line up In the 10 HI curve in the grlph.
Looking to the loll, this corresponds to I damping value (0)01 3.

As mentioned earlier, the calculated value or O is the tot-l dumping desired tor the
entire vibrating system. Some damping may be provided in the cartridge. so you will
arten Ilnd that the but netting at 0 art the DVA it about one grade lower than the
computed value,

CONTENTS OF THE TABLE

MODEL Listed in alphabetic-l Order by manutaclurer

TYPE MM = moving magnet (and related lypas. such as induced magnet. moving iron.
or var tale reluclnnce).

MCH = movlng call with high output. intended tar connection to a conventional
MM phono input

MCL = moving coil with low output volt-go. It: be used with I step-up translormer
pro-preamp. or high-gain Mc phone input

ELEC = electret

F The axial distance lrom the stylus tip to the mounting screws, in millimeters it no
Value is listed, you may measure It yourself II P is equal to 9.5mm. the Clrtrldge
should be mounted with tho screws located midway in the slots 1:: indicated oy
the white dots)

VTF Vertical Tracklng Force. in grams {For milIiNewtons. multiply by10. 1.5 g = Isle
A normal. or median. selling oi the VTF is given a slightly higher value may be
required Ior secure tracking oi the highest modulatlon levels in recordings

up The mass. or net weight or the cartridge. in grams

ea The dynamic compliance or the stylus assembly. measured at inlrasonic
ireouencies iaround ID Hz)
F! The resonant Irequency DI the arm/cartridge system. computed train the "sud

values ol Mp and Cs ll the value is lower than 7 Hz you may remove the white
tuning screw entirely.

a Trta damping grade. on a scale item a the viscous dlmplnqllo 3. (mlxtmum
damping, with the damping rod inserted lully into the limo; The listed value is the
recommended total damping lor the viorating system including any damping
provided within the cartridge, Many cartridges have some internal cantilever
damping (and snure models are equipped with a damping brush), so you may rind
that optimum perlormance is obtained by using a lower value or 0 than that listed.

DAMPING (O)

141

01234501591011
Mp-VTF (GRAMS)