Diminishing returns | Cartridges | Preamps | Record decks | CDsGiven the resurgence of interest in vinyl I've been persuaded to give my two penn'orth, for what it's worth... I remember, when I were a lad, before t' operation, when the fashion for vinyl were at it's peak, much nonsense and expense were wasted on the quest for perfection, when only common sense was needed because hearing is a subjective experience.
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A great deal of resource and energy can be expended on attaining perfection. As one proceeds up the audio quality ladder it becomes quickly apparent, as with anything else, that 'improvement' comes on a logarithmic scale in terms of cost. However, it is a fact that beyond a certain point, this perfection will not be audible, regardless of how much one spends, or how much one convinces oneself. The best example, in domestic systems, would be given by an individual buying a new amplifier because it has 0.00001% distortion. This may sound impressive, but is a pointless exercise when, say, speakers or tape introduce at least 3-5%.
It is interesting that, with the advent of 'superior' digital audio, the most popular means of reproduction is by earphones that would have been shunned in earlier times. Even filtering everything above 7kHz is acceptable. One recalls a debate where a system bandwidth limit of 12kHz would better suit the signal sources and speakers of the day.
Time, place, mood can all affect perception, especially if fashion is being adhered to. Egos can impose themselves on hearing too, even when obvious ear damage is evident. A recent web-search for speakers came up with a quite small pair for $6,000 with optional metal or wood side-panels for an additional $2,000. Then there are some rather nice 130W Class A amplifiers. At €6,600 per channel they ought to be. More recently, a deck intended for domestic use was priced at £18k with matching cartridge for £5k. If the author ever seriously considered spending £5k on a cartridge, he would not be mounting it on a radial arm. As with all fashion, many things are available for high prices to those who may wish to impress, this does not however mean that the spender can (by implied divine right) recognise quality.
For example, the person who can determine a speaker system's impedance by listening to it's performance has yet to be met, experience showing very little subjective or even noticeable difference between 8 or 15 ohm loads. Interestingly, some custom layouts have demanded load limiting with multiples of heavy-duty resistors in series with the speakers. At no time have these arrangements ever been detected by listeners, regardless how critical / sensitive / professional. In fact, to prevent speaker overloads, a suitable bulb can be put in series with a speaker. As the load is driven harder, the bulb's filament's impedance rises, then limiting the current through the load. Those who insist on overdriving amplifiers into low-impedance loads are usually blissfully ignorant of the cost of repairs, when required, and will invariably claim burnt-out equipment is inadequate, rather than themselves.
With the advent of stereo, some record and tape manufacturers did not understand the importance of phasing correctly. Some recordings would change phase from track to track, even with those intended for demonstration purposes! A simple DPDT switch allowing a speaker's connections to be reversed could be used by an enthusiast to remove the defficiency in bass reproduction and the 'hole in the middle' of the soundfield. Most people however, including the experts, were unaware of any problem.
One idiot, in all seriousness, claimed that he could detect the difference in sound between different makes of capacitor, let alone speaker cable. Another, a self-styled aficionado, waxed lyrical and at length of the distinctive qualities of 'the valve sound' emanating from an antique record player unaware that the unit he was listening to was in fact clockwork, and thus devoid of any electrical components. Both could not come to terms with the fact that signal sources can contribute some fifty times the distortion that an average hi-fi amplifier can.
Another individual could not/would not see that his feedback problems were caused by placing a very springy Thorens record deck on a flimsy shelf that he had built above a speaker. Yet another suddenly eschewed his miles of fine-strand silver speaker cables for single-core bell-wire claiming ground-breaking improvement in quality that had changed his life. Middle-aged males (especially former aspiring rock guitarists) appear to be the most oblivious to the fact that their inner ears are irreparably damaged, reducing their upper range to 10kHz or even much less, and to suggest that the 'magical' attributes (see 'Paranormal Audio') they perceive are simply that or that a female's or younger person's opinion might be better is no less than heresy. Ah well.
As an experiment in the early eighties, two identical pairs of stereo power amplifiers, based on an unexceptional and 'normal' circuit, using ordinary, everyday output devices, with two identical power supplies were built up. One was fitted in an older wooden amplifier case and the other in a newer, more modern design that had both been adapted for the purpose. Over the course of a social evening a number of proud audiophiles were invited to pinpoint the differences between them using decent pairs of Celestion, KEF, B&W speakers and identical signal sources (no internal preamps, eq, etc used). The teak-veneered version was described as 'tired', 'muddy' with 'poor definition of transients'. The newer shinier design, complete with flashing lights, drew praise and comments like 'holds the speakers in an iron grip', 'taut and dynamic response' and 'sharp transients with bright attention to detail'. During a subsequent evening the same pattern occurred, despite the guts of one amp having being swapped for those of the other.
This experiment was then taken further with a comparator circuit which could switch a wide range of inputs, amplifiers and (additional) speakers remotely. Listeners were then invited to comment on the sound qualities perceived without knowing which items they were listening to. Differences between speakers were the easiest to spot, as were those between AM and FM broadcasts. However, beyond these, results were very mixed and even confused and it quickly became apparent that subjectivity was dominating the guesswork, even when using amplifiers favoured by 'expert audiophiles' or those actually built by listeners experienced in the field. This was particularly true in respect of exploring 'the valve sound', where an harmonic enhancer (high pass filter of 1-5kHz mixed into the original signal, <10%) gave that 'unmistakable' warmer and mellow 'richness' with any solid-state design used. Similarly, the use of reverb techniques could introduce a wow factor where previously there was none. By offering an opinion in an authoritative or 'helpful' tone it was possible to completely misdirect the guinea pigs. None reported, for example, when signals were switched inaudibly to a completely different system whilst music was playing. Adding any form of intoxication to the equation only served to deteriorate further the ability to differentiate.
On the latter theme, it has been noted that in serious wine judging competitions when samples are duplicated or even triplicated (poured from the same bottle), only about 10% of judges are able to match their scores by as low as 20%. In one famous incident, some 'Wine Masters' were completely fooled by a white wine coloured with red food dye! As with the test described above, general agreement is possible over the best and the worse wines, but between these, in effect, anybody's guess can be valid. A tip; if one is forced to serve a cheap champagne compliment it with thin slices of parmesan and those drinking it will be convinced that it is a vintage. Expectation can also colour results, for example, in a completely unrelated test subjects were served a crab ice cream and told it was a crab mousse which all agreed was delicious. However, when further subjects were served the same dish but told it was just ice cream, the majority verdict was that it was disgusting. A much later experiment showed that diners thought that, amongst other things, food tasted better if the cutlery was heavier.
Invariably there will always be some who will believe and insist that a car will go significantly faster if it's pistons are made of platinum. Others, however, will see little point in doubling the expenditure on a system in order to achieve an improvement of 1dB, detectable only by test gear. A recent discussion of the perceived effects of different AC power cords can be found here.
The author holds that it cannot be underestimated to what extent the brain imposes itself on hearing. We all know that, say, if a recording is made of a classroom and then played back, one of the first comments made is about how much louder and intrusive chair-scraping appears to be. It maybe the case that some cases of tinnitus arise because of long exposures to a noise that the brain is still attempting to feedback to the ear in order to cancel it (as in the chair-scraping). A good example are Royal Navy signallers who, having left the Service twenty or thirty years previously, still hear short-wave mush and random morse. The brain, eager to find patterns because of defensive mechanisms evolved over millenia, can then convince one that voices exist in truly random noise, for example. This might represent a default to a 'cautionary' mode and is in response to a requirement for the most meaningful communication possible audibly sought by another set of synapses. Recent studies of brain scans of tinnitus sufferers surprised researchers in respect of how large the brain areas involved were. A study of the 'vinyl audio chain' suggested a number of pertinent variables that could affect perception (below).
The long-known but often ignored feedback loop between ear and brain is as important as any similar arrangement in any circuit that amplifies.
Biological synchronisations can be seen, with direct comparisons as in those found in shoals of fish and flocks of birds, where rhythmic breathing patterns (in humans 6 breaths per minute seems to be significant) affect the heart, then in turn the frontal lobes and then the entire physiology which create entrainment or unity between nearby people. This can be found in football crowds, raves and can be used by dictators. The repetition of Vedic or Gregorian plain chant can 'still' the mind using a modal system that in the latter can centre around the 'ray' in 'doh, ray, me'. Recitation of the Koran is recommended in slow, even tones. Then there are the mantras like that used for Hare Krishna and Aum (the sound held by Hindus to have been present at the creation of the world). The author has always been impressed by a Greek Orthodox basso profundo. Some cosmologists now see residual Big Bang radiation as an audible signal ('the Song of the Spheres') that can interact.
In complex custom speaker systems the 'rule book' is often thrown out of the window in order to achieve satisfactory subjective results on a purely empirical basis. Delays, especially those inherent in long transmission lines, can be deemed acceptable. The polarities of sub-bass reinforcement might be inverted and equalisation employed to introduce nodes, or iron out defficiencies, that are very far from the flat 'ideal' response demanded by purists. In this context, it doesn't matter then what the test gear might be telling one, but rather what one feels is most comfortable. The polarity of speakers appears to have been considered unimportant in earlier times (this is still the case today with some upright organ manufacturers, although with some cabinets the phase arrangements are found empirically to give the best subjective results in a showroom). A concert hall, for example, might have in excess of a hundred microphones each adding or subtracting to or from the overall mix, apart from any delays or reverb that might be added. A great deal of time and effort will have been expended on the setup and it still may not be 'right' especially since the number of people in the audience will affect the acoustic qualities. London, and other cities, have plenty of famous examples. It is said that one performer at the Albert Hall (built before acoustics were even considered), enquiring of a member of the audience of what they thought of the performance, was told that the listener only heard the first part of the concert, but hastening to reassure the performer, that they had heard it twice. Since then the Albert Hall's seating has been designed to have similar reverberation characteristics to those of people. Cardiff's much-vaunted St David's Hall gave excellent acoustics for the performer (curved wall surrounding stage), but certainly before many improvements were instituted to cut the resonances from the hall's surfaces and fittings many in the audience, including the author, thought it was crap.
Experience has shown that in essence the 'audio' chain, in terms of precedence when pursuing excellence, consists firstly of the listener's expectations, then the listening room, then the speakers, followed by the signal source and finally the amplification employed. Cliques are particularly susceptible to 'herding' tendencies (the 'me too' brigade) largely founded on prejudices, vanity or snobbery. If an individual is keen that their musical or auditory accuity and authority be accommodated then, more importantly, respected and admired if not worshipped, one can be assured that one bodily orifice has somehow swapped places with another. 'Blind' tests are an excellent way of proving this, and can provide immense satisfaction when one's (albeit modified) £35 home-brew amplifier withstands comparisons with £1,000+ 'pedigree' models.
One must determine for oneself whether one's aim is to listen to the music, or the equipment it is played on, and whether one actually possesses the auditory accuity to warrant such expenditure of time and resource given that virtually all of domestic architecture was not designed, or built, by sound engineers. Similarly, the performance or excellence of a item will not necessarily improve simply because one has spent a long time working on it, even though one feels that it must. At the same time, beware of appeals to subjective evaluations, especially if those doing the appealing have something 'nice' and awfully expensive to sell. Alternatively, one can consider the impact of comparable expenditure instead on the extent of one's library or life-style, since, in essence, one is saying that one couldn't find anything better to spend one's money on.
Claims can be considered dubious if, say, it is declared that a new and profound improvement in sound quality is discovered by using x combination of components when all the other elements in the chain are ignored and the observation is made on the basis of an undefined 'musical' quality. For example, with vinyl we have the subjective impositions firstly, of the artist, then the producer, the recording engineer, the mastering engineer, editors, record company management and whoever else there may be, not forgetting all of the circuitry and speakers that the resulting signals have passed through. With the advent of PCs, the internet and 'burning', 'mashing', etc, the numbers of people for whom the tweaking of super-expensive-fi, say, is relevant or even necessary has dwindled rapidly. Usually, the more expensive a hi-fi is, the proportionally fewer listeners it will have, even to appreciate (or worship) it's 'excellence'. Sometimes, the pursuit of excellence can arise when an individual becomes aware of auditory deficiencies but doesn't wish to acknowledge or accept them.
On occasion, upgrading can actually reduce listening pleasure, previously inaudible flaws missed in the editing process then becoming apparent and being anticipated when a given track is played. For example, in the article describing his 1979 headphone amplifier, Linsley-Hood noted when trialing it with two recordings he thought he knew well 'In one of these I could distinctly hear someone, perhaps the conductor, periodically turning over the pages of his score, and in the other, on a well liked and frequently played disc, one could distinctly hear, about half-way through the second side the noise of a music stand falling to the floor, accompanied by a muttered "Oh damn"'. The use of a noise reduction system can sometimes be heard giving a 'breathing' or 'sea-shore' effect.
Few, even amongst professionals, have perfect pitch. For those who do, the music world must be an awful place. Prolonged exposure to high sound pressure levels inevitably results in permanent ear damage, thus the ringing in one's ears after a loud concert. Sensitivity to higher frequencies diminishes with age (presbycusis), and no one can guarantee that at any given time their auditory faculties are certified to traceable standard to be in perfect working order. Add to that the ear's many non-linearities (eg; Robinson and Dadson curves) and the brain's ability to interact with the inner ear, thus subjectively reducing extraneous noise (efferent control of cochlear sensitivity, temporal processing, masking effects with brief tone bursts that extend some tens of milliseconds (often quoted as 50ms) backwards and one to two hundred milliseconds forward in time, the hair cells of the inner ear only reacting to vibrations in one direction ie; during one halfwave of a periodic vibration, etc), and it can be seen that hearing is mostly in the brain of the listener. Just like sight where the blind spot caused by the optic nerve leaving the eye can only usually be detected by closing one eye and moving a finger until it disappears, and even taste whose influence can be negated by the simple expedient of pegging one's nose. For this reason, the author has attempted to avoid, in this project, subjective evaluations of circuitry leaving these to the reader.
For those still convinced that their ears are absolute and perfect passive receptors, a recording made from a small microphone capsule placed at the entrance to the external auditory canal to the eardrum, with care taken to exclude other noise sources can surprise and even alarm. Some cases of tinnitus, which is most often caused by prolonged exposure to loud noise which damages (flattens) the hair (stereocilia) cells of the cochlea (the organ of Corti), can be heard by others without the benefit of amplification.
Some very profound and academic work has been executed by professionals in respect of the quest for the perfect amplifier and/or speaker. Many results can be of great interest to 'audiophiles' but with accompanying bulks, inefficiencies and prices that cannot happily reside in most people's real worlds and, despite immense effort (and cost!), no really tangible benefit that is recognisable by the majority. Such approaches can be emulated but invariably problems will arise that cannot be resolved with locally available expertise, for example, either due to the complexity of the problem/hardware involved, or due to a lack of individuals who can actually hear the desired difference. Before embarking on a grand and invariably very expensive scheme, it is recommended that a thorough and sensible evaluation of resource be made, lest a project spends it's life uncompleted and in pieces.
With live performance, beware primadonnas, their hangers-on and the ridiculous strutting theatricality that can, on occasion, amuse. True artists just get up and simply play for the pleasure of it, they don't make a fuss and are modest. They know that they have a gift that the muse impels them to give pleasure to others, and the pleasure given, and then acknowledged, is a pure celebration of the muse.
Unfortunately, at a number of concerts, large and small, intelligibility is often confused with loudness. High volumes increase distortion arising from reflections and over-stretched speakers, little thought having been given to equalising out either the hall's or system's deficiencies. At the same time, there must be no feedback. Ever.
Long, tedious and unproductive sound checks involving every item in a drum-kit only serve to bore, insult and alienate an otherwise receptive audience. One must always remember that one is there to entertain the audience, not to hurt them. After all, many will have paid. It was a joke that in military circles that artillerymen could be identified by their shouted conversations. The same can safely be said about some musicians.
One well-known vocalist could not hear himself without the harmonics of clipping. Another insisted on playing so loud he emptied the venue. The artist refusing to heed the stage manager's direction, the proprietor had to mount the stage to stop the performance. That performer did not get paid that night much to his very evident chagrin, but quite rightly too. There have even been occasions when instances of deliberate sabotage (power outages, damage, theft, dissatisfied drummers, etc) have been experienced also.
A saxophonist I knew, who died young, said that he played for the newer lovers in the audience with the aim of making their night just right, which I find a much more attractive motive for performing.
Experience showed that the first changes one should make to improve amplified sound quality was to either turn the system down or to change the speakers, most often to a larger size (or their positions), even small amplifiers giving surprising results. This is, quite simply, because it is the speakers that are making the sound that you are listening to. Even 'professional' cabinets lack bracing, more due to economics than design and, as a result, some enclosure's cabinets resonate more than their speakers do. Compared to good quality FM broadcasts, deficiencies in cassette and record decks then became apparent. Most, at that time (pre-CD), would then opt for a new cartridge/record deck combination.
Lucky (?) enough to work in the field, with access to test gear and new products, direct comparison between makes, brands and, more importantly, techniques was possible. Some surprising discoveries were made, especially in respect of manufacturer's expectations and the real world. Many intriguing, and telling, solutions have been met and were tested under dynamic conditions.
The best conditions were given at a venue over about a year and the 'ideal' arrangement was;
Speaker stack (2 off):
4 x bullets; 2 x 12" 200W mids; 2 x 18" 400W scoops (all voice-coils in vertical alignment); RSD 800b 400+400 (bass); Phase Linear 200+200 (mid); Soundout 200+200 (tops); active crossover, all in a wheeled rack behind one speaker; Comberton 12-2 mixer; Technics SL-1210 decks (rafted); selected pre-amps, cartridges and CD players.
It is acknowledged that this 'ideal' is not generally suited to most domestic arrangements, however, several independent and critical opinions could be obtained immediately from a number of professionals. The diversity of programme input was useful for comparison purposes also (vinyl, CD, live performance). The dimensions of the room meant that bass presence was excellent. No reverb techniques were used, or deemed necessary and, at one time, a direct and therefore live output to a FM transmitter was seriously considered. If circumstances do permit, then I would have no difficulty recommending a layout similar to the above.
Run at healthy, but comfortable levels the stress levels evident at other venues were completely absent here. Many venues deliberately have a loud, poor sound not just because of financial constraints but because the stress levels induced can increase sales of drinks. One proprietor, at another venue, was aghast when he saw his customers sit and listen to a system upgrade, rather than crowding the bar.
Having additional access to representative top-line domestic hi-fi, various combinations of cartridge and preamp were tried.
It had already been noticed that some users mix 'n' match styli of one make for those of another without apparent detriment, in fact many decks giving satisfactory domestic or commercial service have been seen where the stylus fitted is neither of the same make or even compatible physical type.
Much personal preference is apparent in terms of favoured makes and can, as such, be the deciding factor. A number who owned high-value hardware fared badly in blind hearings, but less well-off musicians seemed to do better. This was particularly noticeable when 'padding' the input with capacitance. Many, though, could not distinguish between types, let alone makes, even on their own systems, which some owners could not tell were being over-driven into clipping.
An interesting event occured when a 'quality' moving coil cartridge was returned, with great fanfare by the owner, from the manufacturer with a new diamond. The cantilever now freely revolved 360° about it's axis.
Those cartridges that were agreed to perform well had exotic cantilevers and were characterised by high frequency responses, such as the boron-piped Technics EPC-205C Mk3, while others needed mounting kits, such as the beryllium B&O 6000 or 20CL, which used a Pramanik-cut diamond intended for tracking CD4 on a tangential arm. Empires, like the 600LAC (boron-coated aluminium, moving iron), did very well too. Moving coils usually outperformed aluminium-cantilevered moving magnets, giving more detail, but on occasion 'fedback' and for high sound pressure environments moving magnets were prefered.
Some mounting kits proved awkward and in some cases were flimsy, the B&O having two; one for a half-inch shell and another giving a 'Concorde' look (prefered, later copied by Ortofon?).
The times tracking became an issue was if a cartridge was incorrectly fitted or damaged, when dirt accumulated on the stylus or because of a faulty operator. The average arm error gave some 2°32' (outer) and 0°32' (inner) plus the operator error, which can vary considerably. Friction was within 7mg horizontally and vertically. Use was made of a SME 3009 and SME 3012 (both fluid-damped), Mayware MkIII and an Odyssey RP1. Although available, no use was then made of a Beogram 6000's 0.04° tracking error (optimised for tracking CD4 recordings, exploded views of which can be found here), since no improvement was apparently discernible, the most frequently asked question being 'what are we listening for?'. For this reason 'cartridge setting protractors' are not covered on this web-site.
Like power amplifiers, these show great diversity of expression, especially when the designer is given free reign. One wonderful example injected some 60 volts DC on switch on into the signal line. The output of the mag preamp must then be shorted to ground via it's own contacts on the 'shock noise silence relay'. One wonders whether the extra contacts were added before speaker cones were blasted across the room! Then, after that, there may be ten switch contacts in the signal path, which is a bad thing since providing an uninformed but enthusiastic knob-twiddler with lots of knobs to twiddle can only result in contact wear and deterioration.
Useful designs come from John Linsley Hood and I can recommend these, the moving-coil and magnetic preamp designs at two build levels. Very compact combined circuits were built on veroboard giving excellent performance fitted inside the plinths of other decks, once demonstrated (externally) on the 1210. Internal fitting is recommended when there will be no anticipated change of cartridge type, since some plinths may not support an external switch. The preamp can then be optimized to suit.
Surprising results, however, were obtained with lesser and earlier examples, most preamp changes going unnoticed. A very simple 3 transistor design became a prefered choice for many (at the venue mentioned above) and a gain-block for moving coils showed promise.
Purists require that equalisation, in any form, must never be used. In the real world the opposite proves to be true. Although graphic equalisers are often seen (best placed before an active crossover, or power amplifier), preference was given to parametric controls which, in live performance particularly, proved more useful. A light touch is recommended lest system limitations or architectural resonances predominate. Reducing a system's overall output, even by a relatively small amount, will allow greater flexibility, whilst increasing enjoyment.
If fashion is being adhered to, it's always interesting to compare manufacturer's top-line models to see their version of the ultimate. Using record-player arms as an example, one design floated on silicone, another (tangential) ran on precision quartz rods whilst the Odyssey Engineering RP1 tone-arm was available in any finish desired by the customer, including gold. A Revox solution used magnetic suspension, whilst Sony produced one with 16 motors in it. Put that on an onyx plinth with a self-centring turntable and you've parted with some very serious cash before you've paid out for the cartridge, speakers and amp. One reference transcriptor turntable seen at an exhibition 25 years ago cost £4,500, weighed 90kg and could mount three arms. Then there's the more recent £18k deck (with matching cartridge for £5k) ... and you still have to get up to change the record!
Fashion has a tendency to dispense with ergonomics and one notices how user interaction increases with component cost. How many styli, for example, have been prematurely worn out on transcriptor arms that don't lift at the end of a record? How much does one then have to pay (on top of perfection) for this facility?
Early turntables could suffer from quite awful rumble associated with the motor, turntable and transmission system (a 1969 JLH ceramic preamp gave an 18dB/octave cut below 35Hz). Early Garrards and BSRs, for example, used a stepped motor pulley (to give different speeds) to drive an idler wheel which then drove the turntable. A synchronous mains motor was used to obtain speed accuracy, this being dependent more on the mains frequency rather than voltage, eg; rpm = (120 x mains frequency) / number of motor poles +0-3%. The use of a brushless motor reduced mains borne noise. Almost without exception the steel motor spindle was supported by bronze bushes. Because of the relatively small number of poles, sometimes only 2, motor vibration could figure largely and rubber bushes helped to isolate the motor from the chassis. These harden over time and should be considered for replacement on any old deck. Although a ball bearing race often supported the turntable, noise from the motor was transfered to this, and then the stylus, via the idler wheel. Pressure from the idler wheel could push the motor, idler wheel and turntable against their respective bearings, contrary to the axis of rotation, creating further friction and noise. Idler wheel noise could include not only that from it's bearing, but also from flats on it's rim worn by the motor pulley or cracks in the rubber as it perished. At the same time, a stamped steel platter had a high resonant frequency and transmitted vibration easily. One or more soft turntable mats could help. Cheap injection-moulded thermoplastic platters are very much a last resort. Older models would give three speeds of 33, 45 and 78 rpm, later types offering a fourth of 16rpm although the author never found a practical use for this.
Shaded pole motors are normally used since they are non-reversing, self-starting and RF and TV interference-free. The direction of rotation can often be easily modified in a few minutes which can be useful to increase annoyance levels in some situations.
Bearing and motor noise manifests itself as 'rumble' principally because of the RIAA preamp's curve having a bass gain (usually) of about ten times relative to 1kHz. Upgrading to a new cartridge or preamp with a very low frequency rolloff or DC input will then inevitably include content that is not related to the music played, notwithstanding any modulations imposed on the stylus by the arm. Rumble will be more obtrusive when playing stereo records because a stereo pickup is sensitive to vertical vibrations. At 33rpm those associated with the platter or record, individually, will have a repetition rate of some 1.8Hz, a warp halving this. Most LF contributions would extend to some 7-8Hz. A poorly centred record will modulate the stylus radially over a distance of several grooves.
Specifications are often missing from manufacturer's data, it is felt, quite simply because their products performance was that bad.
The Goldring Lenco series attempted to address all of the above by mounting the heavier motor shaft horizontally with a larger 'cone' motor-spindle against which a much wider idler wheel was slid along to vary speed. Larger primary drive surfaces helped to overcome smaller vibrations and a greater mass of turntable helped to regulate speed and increase dampening. The bearing for this was a single steel ball. Since the pressure from the idler wheel was in an upward direction, less sideways 'bias' was applied.
Garrard played with some differing approaches to tone arms. Some more of the memorable examples include the solid teak of the Lab 80 and the dual swivel of the Zero 100. Favourable comment was given to the AP76 which, unfortunately like the very popular (and noisy) SP25 series, could not accept a standard headshell.
B&O, in their Beogram 1202-3000 series (types 5237 and 5228), used an idler wheel and belt-drive, the elasticity of the belt intended to absorb motor vibration. The turntable and arm were suspended from the chassis, as were separately the motor and idler wheel. Speed was varied by raising and lowering the idler wheel against the motor's conical spindle. A belt then ran between the idler wheel and 1.4kg turntable (1.425kg in the 3000). Specs given by DIN 45 500 (p3); wow and flutter <±0.15%, rumble >37db (A) and >60dB (B).
Belt-driven designs could suffer poor service life from the use of flimsy belts which would wear quickly with heavy platters. Some belts, if not used for long periods, would retain the 'dent' of the motor spindle although some plastic types could be revived by dipping in hot water. The pressure applied by the belt, contrary to the axis of rotation of the motor and turntable, as with idler wheels, could introduce frictional noise. Small DC motors could be employed often leaving a lot to be desired. A 'good' earlier type would be the Pioneer PL-10.
Some transcriptor decks had a fashion of raising the record above the platter on raised supports. Although striking in appearance, after all this is art often with prices to match, noise could be transmitted via the higher pressure contact areas. On some designs the pitch between the supports is such that a thin record will 'sag' between them then producing multiple warps, far from a level ideal. The Saturn transcriptor is an example.
Direct drive in effect uses only one moving part, the motor spindle being that of the turntable. A larger number of motor poles (16 or more) reduces vibration considerably. In one system, speed is regulated by converting the back EMF of the motor to a frequency dependent voltage which is then compared to a reference. This then controls three differential switching circuits supplying the drive coils of the brushless DC motor (AN630 IC). Performance is such that light-weight die-cast aluminium platters can be used. Specs given for the Technics SL-3300 - wow and flutter 0.03%wrms (JIS C5521) and ±0.042% (IEC 98A wtd), rumble -53dB (IEC 98A unwtd) and -75dB (IEC 98A wtd).
Although the SL-1210 has become de rigeur lesser models and other makes can perform well. For example, excellent service has been given by a combination of the SL-Q2 and Technics 205C Mk3 moving magnet, with considerable savings over the SL-1210 and 310 moving coil, on a number of systems, professional and otherwise. Against the SL-1210, blind tests with a large number of people proved an inability to differentiate between them, whether the listeners were male, female, old or young.
Personal preference was given to decks whose arms could be touched when the cartridge was removed without hum appearing on the output.
It is a little known fact that a record-deck with captive arm bearings can be played in a number of positions, even upside-down. The record, mat and platter, etc should be fixed before this is attempted for obvious reasons. The Goldring Lenco's wedge arm-bearings to not permit this approach, neither do SMEs especially those with fluid damping. However, an innovative approach where belt-driven Pioneers were attached to a wall (vertically) was seen to work well. Records were held in place by rubber open-reel tape deck grips, the mats being glued in place.
A couple of years ago the author was reminded of a chair that was turned into a record-player, but couldn't remember it.
Avoid light, springy designs. Plinths should have a bit of weight to them and have good feet. Where vibration is expected/inevitable flight-cased decks have been 'rafted' on the thick foam used to restrain the decks when the case is closed with great success, otherwise mass (even paving stones, alternated with layers of rubber, carpet, etc) can be added underneath.
What a disappointment these were. Touted as indestructible, they proved anything but, seemingly more vulnerable than vinyl. Although classical performances benefited, with 'pop' the degree of compression applied so that the content sounded louder introduced more distortion than was evident with vinyl. This newer genre also gave rise to a whole new vocabulary of twaddle (see 'Paranormal Audio').
The compression mentioned above appears to inspire the habit of operators setting critically high volume levels in the belief that the system becomes more powerful, responsive et al. This is not so, in fact the system then becomes vulnerable to a flick of the wrist that can take out an entire speaker bank. Such operators, ignorant of concepts like dynamic range (which can be reduced to some 40dB or even less), are normally averse to supporting the maintenance costs of the systems they break. However, properly managed, given the profound speaker cone excursions that can arise (necessitating the use of limiters where none were previously required), a flexibility can be possible with digitally formatted audio that was not before. Masters of the art are, however, rare.
Manufacturers and Retailers
Design and service philosophies can vary wildly. If buying retail (UK) bear in mind that extended warranties may prove a waste of money since it is the retailer's responsibility to ensure the purchase's function for generally much longer than the normal manufacturer's warranty. If a retailer proves allergic to this concept, have a chat with Trading Standards. Further protection can be obtained if purchases are made with a credit card, especially since some in-store credit can be crippling.
A retailer's primary function, it must be remembered, is to make money, out of you, and the unadulterated nonsense that some seemingly prestigious establishments employ can be quite breathtaking. One salesman at a 'prestigious' music shop claimed that the 'tone' of a speaker or bass drum would be adversely affected if their vinyl covering was scratched!
Some retailers, despite assertions to the contrary, will have no service arrangements whatsoever with manufacturers, buying their stock in on a 'wholesale' basis (ie; the cheaper the better). One client, a regular customer of the same 'prestigious' music shop, attempted to return a faulty software CD and was told, by the manager, "We've sold ten thousand of those and you're the first to complain". Mention of Trading Standards resulted in a begrudging refund. It later transpired that the Manager had lied. The shop had, in fact, sold less than ten.
This same shop lent out an Akai sampler 'on approval' to a favoured customer who, having been similarly slighted, swapped the hard-drive for one considerably less than half the size before returning the sampler as unsuitable. The shop didn't notice, but the next customer probably did. Insist, when buying new, on opening sealed boxes yourself even if the shop is keen to 'test and check the new item on arrival for you'. Broken seals can, in effect, mean it's second-hand and the item should be discounted accordingly. In some establishments, second-hand can mean stolen.
The manager, mentioned above, through stupidity had had a large number of items stolen and promised an individual a substantial reward if he could retrieve them. Miraculously, he succeeded and was flabbergasted and insulted to be offered £50 off any item in the shop as his reward. The retrieved items were then put on display and sold as brand-new, despite several months of use. The same manager had extreme difficulty settling invoices, Trading Standard's assistance being sought before an approach was made to a senior manager who gladly settled the matter on the spot.
On the other side of the hill, as it were, retailers have to deal with the general public (about one in a hundred of whom can be genuine nutters) and consequently have to tolerate all sorts of games when a customer's recent purchase proves too expensive, for example. Then there are the thieves, on both sides of the counter.
Just as retailers vary, so do manufacturers. Let's take a couple. Bang & Olufsen broke ground with their Beogram 4000/6000 series tangential decks, an approach not equalled till the much later Technics SG-165, both of which are worth a look simply from the educational point of view. Everything since, till the advent of digital, has been peripheral.
Specifications, to the uninitiated, can mean nothing. With the differing standards, B&O quoted a relatively poor spec which is easily beaten by the level of engineering employed; while Technics showed a superior spec that some engineers consider optimistic. A good example are power output ratings. Another supplier's item quotes some 420 watts PMPO, which sounds impressive; but this translates as 12 watts RMS (the international value that I prefer), which is quite ordinary. Watts PMPO appear to be variable in that another item quotes only 80W PMPO for some 18 watts RMS. Similarly, a small speaker is described as having a 'sound output of 2 watt', a ludicrous figure, when obviously what is being refered to is the driving amplifier's power output.
Over-engineering can figure also. B&O tuner-amps could be fitted with 'special' bulb-saving circuits to improve indicator life by 40%. The trouble is, when a bulb blew, the FM tuner muted. Technics amplifiers, nicely engineered, feature much temperature compensation that is completely absent from other makes and designs, together with much attention paid to DC conditioning, a part of the audio spectrum not heard by the listener. Attempting to increase reliability by increasing the component count, especially if commercial grade is used, can be a false economy. One TV (Beovision 3500) employed 2 EHT stages, instead of the usual 1. This design was abandoned with good reason. Some of their tuner-amps had a fashion of blowing the mains fuse by shorting the transformer secondary with a triac, under fault conditions. Later modifications recommended removing this altogether, and again with good reason, the trigger circuit being too sensitive.
At the same time, ambitious design can affect performance; slim power amps can overheat badly, the compact design of B&O cartridges, though sleek, reportedly caused a drop in high frequencies at low temperatures (due to stiffening of the cantilever's tiny suspension?) although this wasn't noticed in use (no CD4 decoder was used).
Examining the retail mark-ups can be revealing too. Some manufacturers discount normally and others insist on a minimum 'price-to-customer' to uphold exclusivity. These latter command the higher mark-ups since the turnover is lower. Even so, it is interesting to see how little (compared to the customer's price) manufacturers will let their goods go for. One Panasonic TV promotion offered a week's holiday in Bermuda with every 20 sets bought, the proprietor of a local TV rental company fancied two weeks so bought forty.
In practice both Technic's (Matsushita) and B&O's service departments performed excellently, Technics being quick with parts and B&O having a true expert at the end of the phone when needed (and if you've never worked on B&O, you won't know what I mean). In the same way, service manuals (free to one's dealers) are either not available at all, or available at charge to non-dealers. Some thoughtful manufacturers provided a circuit diagram inside their product's cases.
Commercial designs can be very cheap and decidedly uncheerful and this aspect was the principal factor in determining the author's attitude to valve designs, even towards very well-known makes intended for PA or stage use. At least one manufacturer started with good designs, but then allowed their production team to remove one component after another till the prototype stopped working. The last component removed was then replaced. Voltage and power ratings were then pared to the minimum possible, the components then been sourced from the cheapest supplier. Another, otherwise sensibly built, popular make permanently damaged their (hefty) mains transformers before fitting them, thus guaranteeing an early demise.
Many manufacturer's lost the plot because their Japanese competitors learned what quality meant long before the boards of their rivals did, some offerings being truly shameful. One recalls Aiwa sweeping all before them in the late seventies, British equivalents looking and sounding simply awful.
One lot of speaker switch boxes, despite bearing 'Quality Tested' stickers, had one switch completely disconected, another whose output was grounded, two connected that shouldn't have been and an 'ambio' inductor shorting the two amplifier inputs to each other.
A 'European' brand had speaker baffle boards that were no more than hardboard.
One positively orgasmic reviewer, obviously quick with a screw-driver and proud to be 'at the cutting edge', used up a bag of fuses testing a new high current design against another whilst failing to notice (evident in just one of his own photographs) a bent earth link, a skewed reservoir capacitor, AC power lines bundled with the signal and speaker cables and that there was no air-flow over the heat-sink which was mounted horizontally, instead of vertically, inside the case. Performance was, as can be expected, reported as exceptional, ground-breaking, vastly improved, etc, etc...
This individual did point out, in opening, that GCSE physics had defeated him. Most retail establishments observing his antics would have sacked him. To most 'hi-fi comics', however, he would be taken seriously.
More recently, emails have been received from one Richard who insists on having had remarkable hearing (thirty years ago) and was upset by some of my comments (presumably those relating to vanity and snobbery). It was possible to check his claims with others who remembered him as 'the dick with the magic record', 'an irritating attention-seeker it was easier to humour than explain reality to' and 'a waste of space'. For example, one patient individual had apparently collected his comments and presented them back to him in the form of a graph (reproduced below):
This compared (ignoring the speakers) the distortion ranges in the equipment and media used to those reportedly perceived by 'the dick'. The left hand 100% scale represents the entire signal output. This feedback was reportedly 'met with a vacant expression, silence and clear incomprehension of the implications. The planned illustrative use of oscillograms was clearly unnecessary. Using subtraction techniques, it had been intended to allow the distortion to be audible 'without' the original signal'.
Whilst I can agree that it can be fun for a while to string these individuals along to see what hilarious new laws of physics are postulated to account for their 'superiority' and 'uniqueness', boredom can swiftly follow.
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