Dual CS 606 Review

Page 1

Radio
I
Eleelmn'es Reprinted in its entirety from Radio-Electronics, December 1980

Dual Model 606 Turntable
and Ortofon
ULM 55E Cartridge

RADIO-ELEC-TRONICS AUDIO LAB

I :l I .. Both in terms of lab measurement and
g()lNl: extensive listening tests, the Dual model 606
performed in a most exemplary manner. If you

_RATES_ own, or plan to own, some of the new direct-to-
DUAL 606 TURNTABLE

AND ULM 55E CARTRlDGE disc or digitally-mastered records, turntables such
- as this new Dual 606 come not a moment too
EXCELLENT soon, for such records are more demanding of a
turntable/cartridge system than anything you have
previously played. We were unable to find any
records of either type which posed problems for
this combination of turntable and cartridge.
Considering its price, performance and sound
quality, we would therefore assign a REAL.
rating of Excellent bordering on superb, to this
moderately priced combination.

W I W: Puhnullnnl Inc" run

Page 2

IN RECENT YEARS. MANY AUDIO EXPERTS As
well as audio enthusiasts have begun to realize
the importance ofa proper interface between a
phone cartridge and the pickup arm in which it
is installed. Yet. traditionally. most turntable
systems are supplied without a cartridge. leav-
ing it pretty much up to the purchaser or the
audio salesperson to recommend suitable car-
tridges for use with a given system. Often, the
turntable/pickup arm combination ends up
unable to provide its optimum performance
bemuse of an improper selection of the phone
cartridge.

While Duals model 606 turntable (as well
as their other models) mn. of course. be pur-
chased without a cartridge, the company
makes this model available with an installed
Ortofon model ULM 55E phono cartridge.
ULM stands for Ultra-Low-Mass. and is the
abbreviation that is used to describe this ultra-
Iightweight mrtn'dge as well as Duals com-
pletely redesigned pickup arm.

The model 606 shown in Fig. l. is a single-
play turntable system with semi-automatic fea-
tures. Movement of the arm away from its rest
post and towards the outer diameter of the
turntable platter turns on the direct-drive mo
tor and illuminates the strobe light that shines
upon a series of metal dots located on the verti-
cal rim ol the platter. Alongside the front of
the pickup arm is a cueing lever that. when
activated. gently lowers the arm into playing
position. Although movement ofthe arm to the
correct position must be done manually. a set-
down location aid in the form of an easily felt

ED

detenl is provided for correct positioning of the
arm for 12-inch and 7-inch records. If that
feature is not desired (as. for example. when
seeking other plants in a record). the detent
feature can be turned all" by means of a
knurled knob located immediately behind the
Cueing lever. Farther towards the rear of the
unit. near the pickup-arm pivot assembly but
mounted on the baseplate of the system, is an
anti-skate adjustment control. calibrated sepa~
rately for use with either conical- or elliptical-
ly-shaped styli.

At the front left corner of the turntable are a
speed selector knob and a pitch control knob.
Since the direct-drive motor of the model 606
is electronically driven. speed change and
adjustment are also purely electronic and
involve no mechaniml linkages, The direct-
drive motor used in this turntable is a high-
torque DC servo type. The speed-monitoring
system uses a CMOS regulator circuit and an
integral frequency generafor that, in effect.
checks speed consistency |20 times during
each revolution of the platter.

As for the ULM piLkup-arm of the model

606 it is a refined and redes ned Version of

Dual's higflyLespected straight-line tubular
arm with ten -ngyroscopi_cgimbal suspe_rt_-
deustnble counterweight gs-
shes zero-balance first and then a tem-
pered flat wound spr_ing_applies trac g__ force
d__irectly at the pivo__l_ point wtthout at ing
effective mass of the arm/_eartridge combina-
n.A cross-sectional view of the pivot system
is shown' In Fig.2

IMHFACTURERS PUBLISHED SPECIFICATIONS:

Turntabl- syn-m:

Ml til-noble 12". Plotter Weight: 3.08 lbs. Avail-tat. Spud: 33Vs-Bl'ld 45 rpm.
Tho To Reach w Speed (33% rpm):.2 to 2.5 seconds. Pttett Cannot Range: 10%
Club. Sort-turn tor 0.1% Speed Devi-tho (at 60 Hz): 7.2 divisions per minute.
Hum 0.06% unweighted; 0.03% WRMS. lumbb: (Din-A unwolghted): 50

, dB; (Db-B weighted): 75 dB. Pickup Ann Laugh: 8.7. Often! Ann: 2407 degrees.
T-uontht Treekw Error: 0.16 degrees/centimen Pickup Ann Bearing Friction:
W): 7 mg; (hortlontaly 15 gm. Tm Force flange: 0 to 3 grams. Overall
W (base): 16% wide X 3.5 high X 14/. Inches deep; (Milt duet covert. 5.18
menus nigh.

. ULIES-Efkflridgo (optionally Implied):

W25 grams (lnoludtng brwketohardmtstyttnsmtfimdlahe X 18 um.

ml-uOSStnan-mmym10H2t025kHz.0ut|-rtVett-goettkflz

per mine: 0.7 mv or greater. Channel W at 1 Int: greater than 25 dB.
~mmut1wmm 1.568.8hflevmmm30umlmn
' mwummzswmnnmnmmrmmm 1.0tot.75

unmewrttedTnekMAnguzoeogreeeWLo-dm

41.0mm.mmam¢cmmpr

llllal Model 606 turntable

and Ullfllflll

lllM 55E Galll'lllfle

LEN FELDMAN
CONTRIBUTING HI-FI EDITOR

II

ADIO- ELECTRONICS AUDIO LAB

.IE.
OUND

-RATES-

DUAL 606 TURNTABLE
AND ULM 55E CARTRIDGE

EXCELLENT

mm a our-tsetse morn-wan me. turn

As we mentioned earlier. the combination of
a low-mass pickup arm and an ultra-low weight
cartridge adds up to a higher natural resonance
point that lies above the region of maximum
warp-frequency typically found on recordsi
above 8 Hz and below 12 Hz. However, merely
moving up the frequency of resonance does not
in itself necessarily reduce the amplitude of
that resonance.

Dual's solution to the problem is a mechani-
cal anti-resonance filter housed in the pickup
arm counterweight. That filter is tuned broad»
ly to the range of resonant frequencies that are
to be damped. The owner's manual supplies a
list of some popular cartridges and indicates
the setting that should be selected on a mov-
able calibrated knurled ring located at the
front of the counterweight. based upon w-