Lewis Dalven, resident audiophile, shares his thoughts on product, trends, industry happenings, and why Steeley Dan is the greatest band ever.
By Lewis Dalven
Turntables were the the dominant playback medium for home stereo sound reproduction for over 60 years, from the 20’s to the mid-80’s. In the Long Playing era (1948 on, with Stereo launching in 1958) there was no better way to get top quality sound…open reel tape was too expensive for mass production, smaller tape formats were noticeably inferior sounding, and truly high fidelity radio broadcasting was always rare. Records ruled, despite their faults…susceptibility to damage from mishandling, scratching, and the difficulty many end users had in keeping their players in good working order.
When digital audio first appeared it was in the form of LP records that were made from digital master tapes. This was seen as progress toward a day when all-digital playback would forever end the need to maintain a precisely functioning record player, flip records over, and put up with the ticks and pops that were all but unavoidable. Yet now, over 30 years later, LP playback is enjoying a modest renaissance. Is this a social trend, a fad among hipsters and nostalgic boomers wanting to recapture their youthful enthusiasms, or is there is something that makes analog better than CD or digital file playback? I can’t really answer that big question, but I can say that the phonograph products we are selling today are on average far better than the ones people were buying in the golden era of analog.
While it is still possible to buy cheaply made plastic turntables…ones similar to budget players of the past, the real story is that the quality and precision manufacturing found in today’s better players is remarkably superior to what was the norm in the ’70s. I remember a very popular European turntable that only rarely came through with the head shell square to the platter, and for the sake of convenience many turntables were fitted with flimsy removable cartridge mounts and end of record lifts that seriously impaired their integrity as sound reproducers. Fortunately or not, phonographs are no longer a mass market item; their designers cater to the quality conscious and focus on the fundamentals.
The following is a summary of the fundamentals of a phono-based playback system:
Turntables need to do 3 things:
• Spin smoothly at the right speed (33 1/3 RPM)
• Introduce as little noise as possible
• Reject outside vibration and noise
Tonearms need to do 3 things:
• Hold the stylus stably in an optimal relationship to the record groove in 3 planes
o Azimuth (square to record surface, viewed head-on)
o Zenith (Vertical Tracking Angle)
o Yaw (Lateral Tracking Angle)
• Add no unwanted friction or torque to the stylus/groove interaction
o Some intentional rotational torque is called “Anti-skating force”
• Add no spurious resonance or tonal coloration to the reproduced sound
o The use of carbon fiber in the arm tube or the addition of internal damping materials can help control resonances.
Cartridges need to do 3 things:
• Accurately convert stylus tip motion into electrical signal (transduction)
• Maintain tracking integrity on records of all modulation levels (tracking ability)
• Deliver enough output voltage to prevent electronic background noise from being audible
o Paradoxically, the costliest cartridges sometimes have very low output.
Phono Preamps need to do 3 things:
• Adhere to the RIAA EQ curve accurately
• Have sufficient overload margin to avoid distortion
• Have enough gain and low enough noise to make the electronics quiet relative to the surface noise of the record.
Turntables fall into several classifications based on drive mechanism and suspension method.
Drive Types:
• Belt – the simplest way to go, used by AR, Thorens, Linn, SOTA, etc.
• Direct – introduced and championed by Technics, favored by many Japanese manufacturers from the 70’s on.
• Idler (aka rim drive) – used mostly on “record changers” requiring high torque to operate record dropping mechanics…an abandoned category today.
Suspensions:
• Sprung subchassis – used by AR, Thorens, B&O, Linn, SOTA, etc.
o Subchassis with a high center of gravity can make it more susceptible to skipping if not placed on a vibration free surface
• Motorboard (plinth) with damped feet – used by many current ‘tables
o Can be lighter or heavier, feet can be sprung, rubber, or even use magnetic-repulsion. All variables affect the resonant frequency, which defines the ‘tables behavior in the 0-20Hz range. See below.
Other turntable features include different platter materials and bearing designs:
Platter bearings:
• Extreme precision in bearing tolerance is the hallmark of most expensive ‘tables. Bearings are a primary determinant of rumble.
Platter Materials:
• Most of the better turntables have used die-cast aluminum with a thick outer rim for increased “flywheel effect”, often employing two-piece construction with an inner platter being belt driven, and the motor being positioned between the inner and outer platter rims. Other designs place the motor outside the platter, with the belt visible on the outer edge of the one-piece platter.
• Other materials have gained popularity, particularly acrylic, glass, and more recently, MDF, both for their non-ringing characteristics and lower cost.
• Many high-end ‘tables employ “sandwiches” of several materials.
• Lower priced turntables have often used stamped steel platters
Tonearm Types:
• Pivoted – Almost universally used in today’s market. Can vary by length, bearing type, method of applying tracking force, use of damping materials, etc.
o Key parameter is Effective Arm Mass – determines optimal cartridge compatibility. High mass must go with low compliance, and vice verse.
• VTF usually applied by “static imbalance”
• Linear – once the next big thing, now mostly abandoned commercially.
o Classic linear arms include Rabco, Souther, B&O, and the many Japanese models by Technics, Yamaha and others.
Cartridge Types:
• Moving Magnet/Moving Iron
o Best selling HiFi design, typically with user-replaceable stylus assembly.
o Wide range of body weights and compliance.
o Can be sensitive to tonearm cable capacitance…may need capacitive “loading” for flat response depending on coil inductance.
• Moving Coil
o The standard in High End systems – preferred by connoisseurs for airy, extended treble response, solid bass, transparency.
o Can be low output or high output – low requires additional gain and impedance matching at the preamp level, but exemplifies the MC sound most fully.
Stylus/Cantilever Types
• Spherical or Round – typical of lower priced HiFi or Pro-DJ styli, distributes force more broadly, tracks heavier, rolls off highs, inner-groove challenges.
• Elliptical – The norm for most HiFi models, can be subltly elliptical (.3x.7mil) or more extreme (.2x.8mil), can be bonded to a metal bushing, or “nude” (solid).
• Line-Contact – Even more vertical record wall contact, reduces wear factor and inner-groove distortion and increases high frequency extension and tracing accuracy, but is more critical of alignment setup and cleanness. The Shibata stylus is the granddaddy of LC styli, but others include Fritz Gyger, Van den Hul, and Micro-Ridge. Almost all of these are nude, and are the costliest type.
• Aluminum tubing – the most common cantilever material, usually crimped at the end. Some makers used tapered tubing to reduce tip mass. With “nude” styli, the diamond shank is often rectangular, and the laser-cut hole in the cantilever is as well, assuring proper perpendicularity of the tip shape to the groove.
• Titanium, Boron, Ruby Crystal, Quartz – At the High End, anything goes! These babies can cost thousands!
The Effects of Resonant Behavior
The most commonly observed effects of resonant interactions in phono systems are acoustic feedback, and groove-jumping. Each is the byproduct of system matching and setup choices, and can be resolved by some rearranging or other measures.
Acoustic feedback occurs when bass energy produced by the speakers’ woofers reaches a threshold of volume where it excites the stylus/tonearm system to generate additional output, creating a “positive feedback loop”, making a low “howling” noise. In severe cases, the arm will actually pop out of the groove! The solution is to lower the volume, move the turntable away from the speakers, or select a cartridge better matched to your tonearm, usually one of higher compliance.
Groove jumping occurs when a low resonant frequency suspension is used with a high compliance cartridge in a structure that suffers from “footfall shake”. This condition afflicts many wood-frame homes, and leads to the “You can’t dance” phenomenon. Many turntables with loosely sprung suspensions are tuned to frequencies below 5Hz, which is where footfall shake lives. When excited, these ‘tables rock and sway, and inertial effects on the arm/cartridge conspire to upset playback. The best solution is to place the ‘table where the floor is more stable, or to mount it on a wall-shelf, which is usually unaffected by floor vibrations. Of course, a ‘table tuned to a higher frequency would be less susceptible. 12Hz is the optimal number…lower and you get groove jumping; higher and you get acoustic feedback.
Other Factors
There once was a big debate over Direct Drive versus Belt. Only a few direct drive ‘tables are in production today, favored by DJs, A case has been made against the use of servo-controls in turntable motors, which is intrinsic to direct drive, and may partly explain why critical listeners don’t prefer their sound. There are arguments about the benefits of massive platters and plinths versus lightweight materials. There are advocates for heavy arms, paired with low compliance/high tracking force cartridges, versus low mass arms with high compliance, low tracking force cartridges. Most of today’s models occupy the middle ground.
MM cartridges once dominated the cartridge discussion. Thankfully, the mania over achieving the lowest possible tracking force has blown over, with today’s models of all types tracking at a sensible 1.5 to 2.0mN. Most serious listeners who have tried them do prefer MC cartridges, but at least two highly regarded brands, Grado and Soundsmith, use the MI principle in their products. The best of today’s MM cartridges are very good too, and more practical for the non-hobbyist seeking quality playback than most MCs, being less costly, and generally having user-replaceable styli.
Subjective Quality
If you read turntable reviews you will hear about “pace”, “tunefulness”, “sound emerging from a black background” and other such balderdash. These subjective descriptors are reducible to the objectively measurable “speed accuracy”, wow & flutter”, and “rumble” respectively. But like most specifications there are various methods and standards for the measurement of these and quoted numbers are not always carefully qualified, with the result making by-the-numbers comparison mostly a fruitless undertaking. Few things are harder to pin down than “how a turntable sounds”. The interdependence of the individual components making up the system, and their suitability to their environment, associated electronics, and speakers create a complex problem for the enthusiast or consumer, and for the sales representative trying to convince the prospective buyer! I can only relate that belt drive is good, stable construction (not flimsy) is good, a tuned frequency around 12Hz is a safe bet (not too wobbly, not too stiff), any discernible “play” or “chatter”, or friction in tonearm bearings or any “liveness” in the arm tube is bad, that I prefer a damped aluminum, acrylic or sandwich platter, I believe in spindle clamps (or weights), and I absolutely prefer nude, preferably line-contact styli. All these items in one product today makes for a somewhat expensive turntable, like the Pro-Ject Perspex 6 Super Pack, at $2,000.00, But a healthy slice of my likes can be had for $799.00 in their Xperience Basic + Acrylic. And the perfectly decent Debut III can be had for as little as $299.00.
Care & Maintenance
There are three elements: Getting a soiled record clean, keeping a clean one clean, and keeping the stylus clean…dust balls are bad news! The best products are:
• A record wash system like Disc Clean, used only to remove smudges, food, etc.
• For routine maintenance, a Carbon Fiber record brush, (Pro-Ject Brush-It)
• A dense carbon fiber stylus brush (Pro-Ject Clean-It).
• I recommend replacement of poly or paper record sleeves with anti-static “rice paper” sleeves, sold by Mobile Fidelity and others.
Also:
• Keep records away from direct sunlight, heating, moisture – to avoid mildew.
• Store them vertically, not too tightly packed
• Always return records to their jackets promptly
Outdoor eave speakers are a great way to get good sound in the backyard. Outdoor speakers are typically marine grade speakers with the ability to withstand the most rigorous atmospheres. From your home close to the ocean to the frozen winters of the north.
Rock speakers are a more incognito solution as you can disguise them into your garden areas or in a mulch area. The good news is most of the rock speakers sold here at Audio Concepts have a lifetime warranty. You can leave them outside in any amount of snow and you are still covered.
With outdoor TV’s available you can also bring that technology to your pool area or patio without taking it in in the winter or even covering it during the winter.
