The Vinyl Vault, Part one
Optimizing your turntable
i. Tracking force:
Vinyl records produce sound when the stylus tip touches the groove walls and the platter rotates. Obviously the sound will be better when the stylus remains in contact with the groove walls at all times and if there is no interruption of this process. The correct tracking force will optimize the playback and make certain that there is correct tracking and tracing of the groove, with the minimum of wear and tear possible. Many years ago accepted thinking used to be that less wear-and-tear would be made with lighter tracking force, but generally this thinking has changed dramatically as a more secure fit and prolonged groove wall contact has actually been proven to give less wear-and-tear. Imagine, if you will, the stylus tip riding up and down the groove wall and even loosing contact with the groove surface and then crashing down a split second later. Damage is bound to occur – the process can be compared to a surfer riding the wave and leaping over the crest of the wave and then coming down without too much control of where he lands and how he continues. Continued contact of the feet on the board and the wave will ensure a smooth and continuous ride from wave inception right up to the beach with minimum friction or effort.
There are basically two methods available to get the correct tracking weight. Measuring can be done by hand and a manual scale, where the stylus tip is put to rest on the one side of a device that looks and works like a see-saw, with the weight on the opposite side of the see-saw. With calibrated lines and weight markings these devices are simple to use, surprisingly accurate and inexpensive.
Digital scales are more advanced and cost more money, but they are far more accurate and the increments are in 0.1 grams. Ortofon manufactures the DS-1, which is easy to use and avoids the common pitfalls of larger scales that sometimes require the platter to be removed to accommodate the proper height of the arm (the arm should be level when the weight is dialed in). With the DS-1 you simply put in on the platter directly, place the stylus tip on the metal plate and adjust the counterweight until the correct force is reached. Manufacturers all give a minimum and maximum weight range, with a specific recommended force for each cartridge. The DS-1 is supplied with a little handy carry pouch and works with two supplied batteries. It is currently selling for R 1140-00 inclusive of VAT. Very often a group of vinyl users purchase such a unit amongst themselves and use it when required.
ii. Cartridge mounting:
The cartridge does not have an enviable task. It needs to move up and down and from side to side in grooves that have very small dimensions. If the cartridge has not been mounted properly larger movements are present than those typical of grooves and their vibration, and music will be lost. Do not mount cartridges with plastic washers. Even worse – do not use plastic screws and nuts. Those units were very much in vogue in the early seventies, but fortunately they are no longer relevant (unless somebody has forgotten to change the cartridge for many years and has only been replacing the stylus periodically). The majority of manufacturers now include decent mounting screws and nuts with their cartridges.
In many cases older or more advanced arms have been designed with a headshell as part of the arm’s functioning. The head shells that are supplied with the arms are not always of extremely high quality, and there are numerous replacements available that will provide much more stable platforms to mount cartridges on. Ortofon manufactures four different models with superb engineering that make use of advanced materials and are rigid and will not vibrate or introduce sound coloration. The entry-level model is the LH-2000 and features solid aluminium. This model is followed by the LH-6000 of magnesium, the LH-8000 which is made of beautiful polished hardwood with brass fittings, and ultimately the opt-of-the-range LH-9000 which is a composite of magnesium and carbon fiber. These models can replace basic head shells on various arms and will offer immediate improvements.
iii. Calibration via protractor
We spoke about mounting the cartridge securely into the arm/headshell, but there is something crucial that needs to be performed when we do this. Remember that the there is only one groove that runs across the entire surface of one side of a record. The stylus needs to follow this groove from start to finish until the last song on each side is reached. But the groove is actually straighter at the start (less curvature), and progressively get more and more curved towards the centre spindle (as the curvature becomes more pronounced). There should be no difference between the relationship of the stylus at a 90 degree angle to the wall and itself, irrespective of where the stylus is at the start or towards the end of the record. If the stylus is not aligned properly within the groove the wear and tear factor would be bad across the entire surface of the record, but also worse at it goes towards the end. Various protractors are available that help with alignment within the arm and headshell in relation to the groove. These can be purchased but invariably there are many websites that offer free downloads. You may want to do a web search for them, or visit www.vinylengine.com for material. Protractors will generally also offer overhang distances, the correct arc across the record surface and also correct distances and angles of the arm in relationship to the cartridge and turntable in question. A good protractor is an indispensable tool for turntable users that mount their own arms and also for turntable builders.
a. Different types
There are essentially only two different types of arms, although there are many variations of technology that offer the same end-result of what an arm should be doing, and that is to provide a stable platform for the cartridge to enable it to do its unique work properly. The main types are as follows:
1. Straight or curved arms that have a central pivot point and are fixed onto the side of the turntable, either to the plinth or to a dedicated arm board or other mounting option. The majority of arms fall into this category and some of the best arms in the world work comfortably in this manner. These arms are usually one of two types, namely either statically balanced with the counterweight being measured with a scale and then left in that position once the desired force is reached, or dynamically balanced, where the weight is applied by means of a spring or tension device to apply the desired force. Please see two examples here of SME, one is the SME V straight tone arm and the other is an older SME curved, or commonly known as an S-shape arm.
2. A straight linear tracking arm that moves in a straight line across the surface of the record. With linear tracking arms there can theoretically be no tracking distortion as the stylus is always correctly aligned in relation to the groove (unless the cartridge is mounted skew, but this not very likely to happen as the majority of linear arms are quite expensive and are usually set up by specialist dealers). There are various ways in which linear tracking arms can function, e.g. air-driven, servo motor-driven, etc. The following image shows a linear tracking arm mounted on a Walker Proscenium Black Diamond II.
Ortofon produce two types of arms – a statically balanced unit and a dynamically balanced unit. There are three models. The most affordable unit is the TA100, followed by the AS-212S (statically balanced), and the AS-212D (dynamically balanced). Prices can be calculated upon request. These units are very popular amongst turntable aficionados, especially those that like to build custom turntables and manufacture their own plinths and arm boards to mount their choice of cartridges. They are all manufactured to very high standards and have tight tolerances on their bearings and offer superb and unfussy performance. Very often turntables can be ordered without arms. These are usually high quality turntables where the choice of what needs to be used and fitted will depend on budget, design and type of cartridge. These arms offer simple and efficient solutions. Shown here are the TA100 entry-level unit and also the AS212 unit.
The counterweight has a simple yet very important function – it needs to counterbalance the cartridge on the other end of the arm and keep it in a constant position relative to the record. It stands to reason that it should not slide around or move and introduce additional and unwanted vibration. The majority of counterweights have a range applicable as to which cartridges can be used. They are usually fitted to the arm and will remain in one place under normal working conditions.
There are cases where arm manufacturers do give optional weights that can be used if the cartridge in question is heavier (or lighter) than what the arm can cater for. These can be purchased separately and are very easy to exchange with the old or unwanted ones. Project turntables have units available for R 170-00 rand for the majority of their arms. Ortofon also do a variety of counterweights for their arms. They have counterweights available for both their 9 and 12 inch arms.
d. Arm boards
In many turntables users have the option of mounting different arms of their own choosing. There are many reasons why users would want to use different arms, as there are many manufacturers of high quality arms that make use of different materials, have very different and divergent design philosophies, and in many cases turntable manufacturers do not produce arms and the idea is to make provision for different choices that are available.
In such cases arm boards can be supplied separately, either pre-drilled for the arm in question, or simply blank, where the user will have to do his own drilling and mounting. Arm boards are made of many different materials, but it is fairly safe to say that the majority of arm boards will at least be made of materials that have certain absorbtive qualities and will not add their own coloration to the sound. In many designs the arm board is an integral part of the design (e.g. Linn, Ariston, etc.), and in other cases the arm board material can even be mounted totally separately from the turntable and motor base so that no movement or vibration is transferred at all. Arm boards need to be strong as the arms that are mounted will usually be tightened very securely to them.
In the next installment we will have a look at some of the interesting retro turntables out there and how popular the custom turntable market has become, and also aspects of phono pre-amplification and related topics.