Dual CS505 turntable
Building blocks in many a budding hi-fi buff's first separates system, Dual's series of CS505 turntables is regarded with great affection to this day. We test the CS505-2 Review: Tim Jarman Lab: Paul Miller
ABOVE: Every student's dream and a first step on the road to the high-end - a black Dual CS505-2 with a smoked acrylic lid, often paired with a NAD 3020 amp driving Wharfedale Diamond speakers
LEFT: These original (German) flyers for early and late versions of the Dual CS505 show that aside from the styling of the plinth and platter little changed in its design over the years
If you were just taking your first steps into the world of hi-fi in the early 1980s there was a tried-andtested upgrade path through the various types of equipment on offer. You'd probably start with a radio-cassette player, then move up to one of the highly affordable music centres as you began to put together a record collection. Assuming that your curiosity and thirst for a better sound remained, the next step would be to assemble a separates system. Although at the time there was a vast choice of models available for this key transitional moment, just a few really stick in the memory. One, of course, was the NAD 3020 amplifier [see HFN Nov '12] while few of us bought a turntable without first giving serious consideration to the Dual CS505 or one of its later iterations. Often partnered by the canny hi-fi buyer on a budget, these two components started many listeners on a path that would bring countless hours of pleasure and enjoyment. In the 1960s and '70s Dual occupied a similar place in the German market as did BSR and Garrard in the UK, producing
numerous drop-in idler-drive turntable units for music centres and combination units. Despite being associated with the lower end of the market, the marque established a niche, retaining audiophile credibility for the quality of its separate belt-drive units, which sold well across Europe.

The CS505 first appeared in 1981 as a simplified version of the already established CS506. Changes included the use of a simpler platter and the removal of the illuminating lamp for the strobe rings around it. The deck filled a place in the market that had previously been occupied by the likes of the Pioneer PL-12D and Sansui SR-222 - simple designs that had delivered sound quality way beyond their lowly price points. The CS505 met with instant success, so much so that by the time the revised CS505-1 appeared in 1982 it was already the best selling 'proper' turntable in the UK.

DEFINITIVE VERSION

The CS505-1 featured a lightweight cartridge to complement the deck's famous ULM (Ultra Low Mass) arm along with a revised counterweight. It also came with a restyled moulded plinth, available in black or silver, which tapered inwards towards the top. At £75 the CS505-1 was something of a bargain and perhaps the definitive version of the 505 series, but further changes were to come.

ABOVE: Against a sea of matt black two features strike the eye - the ultra low mass arm and the strobe rings around the aluminium platter, though there was no strobe lamp
LEFT: Close-up pictures of an earlier Dual model show how certain design features, such as the arm pivot and the detail of the cueing lever, were carried over to the CS505

The CS505-2 - the model tested here - returned to a boxy-looking plinth with a wooden perimeter which could be ordered in a choice of two veneered finishes or plain black. Changes were also made to the headshell so that it could now be unscrewed from the arm. Previously a carrier-block holding the cartridge was used, which could be released by folding the cueing grip backwards. The CS505-3 introduced the 'Audiophile Concept' theme, but in reality little had changed. The only items of real note were the removal of the strobe rings from the rim of the platter altogether (which was now vertical rather than being angled) and a revision of the styling of the mouldings around the cueing lever.

ECONOMIES OF SCALE

The policy of minimal alteration continued with the CS505-4, recognisable by its black bearing mount at the arm base. Previously this part had a profile in natural aluminium. The CS505-4 also featured revised arm wiring and a simpler method of connecting the signal cables. It also came in a choice of just oak or black finishes for the plinth. To call the CS505 a cheap turntable is perhaps a little unfair. 'Inexpensive' is probably a better description, but it is

important to appreciate that the low cost was made possible as a result of efficient and rationalised mass production, not through penny-pinching when it came to components used, materials and finishes. Take the platter for example: it looks like the die-cast affairs to be found on the big Japanese decks of the period, but in fact it is made from pressed aluminium sheet which is then machined to make it attractive and accurate. A thick rubber mat effectively damps the ringing that would otherwise emanate from such a lightweight metallic structure and as a whole it looks good and runs true. All through the CS505 extensive use is made of moulded parts made from filled polymer (or black plastic if you prefer), which - when you are considering a production run of tens of thousands of units - is simply the best way of fabricating the sheer number of small components that make up a polished product. These days you don't get much in the way of technical intricacy in a budget turntable, but the CS505 has more than a few features worthy of interest. Firstly, the expanding 'Vario Pulley' allows the speed of the deck to be fine-tuned by changing the size of a segmented motor pulley via a mechanism which forces a tapered

shaft into its end. The motor itself is a synchronous type which is locked to the mains frequency and therefore cannot be adjusted. Previous Dual turntables featured a similar arrangement, but the pulley size had to be adjusted using a screw mounted on the top of the actual pulley, meaning that the deck needed to be stopped in order to alter the setting. In the CS505 this is not necessary; rather, a set of cams, levers, gears and a tiny toothed belt bring the adjustment out to a knob which is concentric with the speed selector. There is also an interlock that disables the speed selector unless the platter is turning. This prevents the belt being damaged by an inexperienced user. Finally, whenever the arm is returned to its rest the cueing lever is automatically set to the raised position, protecting the stylus when the arm is next moved.

QUESTION OF BALANCE

In fitting my reference Ortofon 2M Bronze cartridge to the CS505-2 used in this review I experienced some difficulties in getting the arm to achieve the necessary 2g of downforce, since the original cartridge (also made by Ortofon) was very much smaller and lighter. Eventually I settled on reducing the dynamic balancing dial to zero and setting the downforce by adjusting the counterweight with reference to a stylus balance placed on the platter. This method allows the weight to remain sensibly close to the arm pivot, which is beneficial to arm behaviour in general. Anti-skating force has

RIGHT: The straight tonearm was both light arid rigid. The CS505-2 featured a removable headshell while previous versions had a sliding carrier released by rotating the finger grip
LEFT: Even after years in production the CS505 dominated the £100 turntable sector, as this 1985 reprint of a review in Hi-Fi Choice shows. It even trounced Dual's other models in the test!

to be dialled in manually, but the control is clearly calibrated and has scales for both conical and elliptical styli.
Cartridge fitted, the Dual slotted nicely into my reference system which comprised a Cambridge Audio Azur 651P phono stage, Cyrus 6A amplifier and a pair of Monitor Audio PL100 loudspeakers, the whole lot wired together with Chord Company Calypso and Odyssey 2 cables.

TIM LISTENS

Using the CS505-2 is simplicity itself: the motor starts as the arm is swung out of its rest so that when the stylus is over the track you want to play, the damped cueing device drops it into the groove nicely. There is no muting system (as some semi-automatics have) so this still has to be done with a bit of care, but the arm raises itself unobtrusively at the end of the record without any drama. Many modern turntables use a relatively weak motor and thin drive belt in conjunction with a heavy platter to form a stable drive system, and this is one area where the Dual differs from current practice. Its 16-pole AC mains motor is relatively powerful and the flat belt gives positive power transfer to an extremely light platter. There is little in the

way of flywheel effect, to the point that the platter can be seen to 'rock' on the elasticity of the belt when the machine is switched off. This absence of stored energy suggests that the deck should not suffer from the very low-rate drift present in some high-mass designs [see Lab Report, p118] the result being that the sound is breezy, brisk and airy while timing is explicit. It's a sound similar to that of a basic direct-drive turntable. No doubt the exceptionally light arm contributes to this too; together they give a distinctive sound which is very enjoyable.

I began my listening with the track 'Dancing With Tears In My Eyes' by Ultravox, (from the album The Collection [Chrysalis UTV1]. As well as the strong and stable rhythm, the Dual revealed a fine vocal presence largely free of midrange muddle - not to mention a nice big 'walkin' soundstage, which suggested it was working well with the cartridge. Treble detail around the percussion was perhaps slightly veiled, but this is a minor criticism. Overall, the presentation was surprisingly good.

SOLO PIANO

Despite the fact that the deck's top plate is spring-mounted, I did find that careful positioning was essential otherwise acoustic feedback could affect the precision of the bass. The deck's thin plastic bottom cover and delicate arm are both sensitive structures it seems. An expensive hi-fi rack could be one answer; that old student hi-fi stand-in - the paving slab - could be another (especially if you are using the turntable in an attempt to rediscover your lost youth). To see how the CS505-2 would handle more serious musical fare I tried it with the beautiful recording of Beethoven's 'Fur Elise' [Philips Digital 412 227-1], Here the Dual demonstrated a pleasing fluency

ABOVE: To the rear of the 505-2 can be seen the fixed cabling and plastic under-tray. As this is a semi-automatic, the tonearm and cabling are integrated into the design
ABOVE: Wow and flutter re. 3150Hz tone at 5cm / sec (plotted ±150Hz, 5Hz per minor division). Speed accuracy is spot-on but low-rate wow slightly high
ABOVE: Cumulative tonearm resonant decay spectrum, illustrating various bearing, pillar and 'tube' vibration modes spanning lOOHz-IOkHz over 40msec
ABOVE: An assembly drawing for a later Dual CS505. Setup was quick and easy

around the individual piano notes. A slightly warmer tonality may have suited the piece better but each note was solid and steady - not always a given with belt-drives. In absolute terms one could perhaps have wanted for more clarity around the textures that give each note its own distinctive character, but then we're talking here of a deck that costs a fraction of the price of the best on the market. An impressively quiet background was another aspect of the CS505-2 which I came to appreciate while enjoying the Beethoven. Rumble appeared to be well suppressed and hum (both mechanical and electrical) was subjectively absent.

FEW PITFALLS

Buying one of the CS505 series secondhand has few pitfalls. They are well made and reliable machines. The most common fault involves the little toothed belt which operates the pitch control function but which can also break. This is not important so long as the speed was set correctly when the belt failed, but even if this is not the case it is possible to pry the driven gear

round in small increments through the slots in the platter until the right point of adjustment is found. More alarmingly, clouds of smoke from the underside can result if one of the capacitors on the mains switch PCB fails. The transparent yellow Rifa types employed are none too trustworthy, especially if the deck has been stored in a damp environment. Despite the dramatic visuals, little other damage is usually caused and replacement is straightforward. The various levers and linkages that form the automatic shut-off mechanism are well engineered and should need no attention or adjustment if the deck has been looked after. Between £50 and £100 should buy a decent secondhand Dual, although one with a recent high quality cartridge whose sound is to your taste may be worth paying a little extra for. And remember always to treat it to a new belt. The neat looks and crisp sound of the Dual CS505 series make it something of a bargain at these prices. Some things never change. (!)

HI-FI NEWS VERDICT

Dual's evergreen budget turntable remains an excellent way to get into the gentle pastime of playing records. It remains a desirable asset today, not just for those who enjoy collecting vintage components but for everyday listeners too. Being well engineered and reliable and still in plentiful supply secondhand at very moderate prices, it has lost none of its appeal decades on.

The merest tweak of Dual's (±6%) pitch control was required to bring the deck's 33.3rpm speed on-song although, as the W&F plot illustrates [Graph 1, below] a deal of very low-rate wow (drift) blurs its precise pitch by ±3Hz whether the deck is set to run slightly fast, slow or spot-on. Nevertheless, the peak figure of 0.1& is not far off Dual's own specification. The low -69.5dB DIN-B wtd rumble is also bang-on Dual's spec, and very impressive by vintage or modern standards bearing in mind the relatively lightweight 0.9kg alloy platter and obvious torque of the 16-pole SM 100-1 synchronous motor. The-67.9dB unwtd hum and noise is also a credit to the internal arm wiring and bests many a deck from the current era. The accompanying arm is surprisingly clean from a resonant standpoint. The cumulative spectral decay plot [Graph 2, below] highlights a major peak at 345Hz from the very lightweight but rigid alloy tube even though the primary bending mode is closer t o l 15Hz. Modes above 400Hz and up through the midrange and treble are very well damped - an impressive result and also more than a match for today's arms. No doubt, the performance of the 505 wand is boosted by the fact that Dual's semi-auto mechanism disengages from the arm during play. The 4-point gimbal bearings are sound and possessed of little friction although the spring-loaded tracking force gauge was a trifle heavy-handed, under-reading the applied force by nearly 20% in our sample. Readers may view a comprehensive QC Suite test report for this Dual CS505-2 turntable (and accompanying tonearm) by navigating to www. hifinews.co.uk and clicking on the red 'download' button. PM