Chapter

equipment

People can be rather strange. We pride ourselves on being logical, and then, time after time, we fail to follow a technological advance to its logical conclusion. A fairly good example of this was the early development of the automobile. Remember those photographs of the first cars? They took the "surrey with the fringe on top," got old Dobbin off the front of it, cut him down in size and put him on the inside, leaving the remainder of the carriage just about as it had been before. They even called the thing a "Horseless Carriage." In those days, they didn't seem to realize that they were dealing with something that was essentially new and should be designed new from the ground up.

In many ways, the contemporary hi-fi system is about as different from the radio and radio-phonograph of a few years ago as the internal combustion engine was from old Dobbin. Possibly this is why a good many people who have been trying to put hi-fi systems into a housing equivalent to the "surrey with the fringe on top" have been dissatisfied with the results.

To carry the analogy a little further, both the automobile and the "one-horse shay" had the same original basic purpose—getting people and things from one place to another. But through development and refinement, the automobile became transformed into a completely new object that does a far better, faster and more comfortable job of transportation than would ever have been possible with the "one-horse shay."

Similarly, the basic purposes of the older radios and phonographs were the same as that of present-day hi-fi—the transmission of a sound from one place to another. But here the parallel ends. High-fidelity is the result of continuous advances in the science of electronics and ever present refinements in the art of audio reproduction. But, as in all arts, the final word has not been said.

One of the areas where considerable refinement must still occur lies in that of the furniture in which the equipment is housed. After all, you've probably spent a good deal of time, effort and money in making a pleasant and comfortable living room, and you are therefore understandably reluctant to admit a Frankenstein's monster to a permanent place in it. Before you can intelligently decide what kind of furniture you want to put into your living room to house the hi-fi set, you must first examine the system itself to see what it requires in the way of space. To exhume an old cliché, "You can't put a quart in a pint bottle." So, let's take a look at the equipment and see how big a bottle you do need.

I shall not discuss the relative merits of different kinds or makes of equipment; a tremendous amount of information of this kind is already available in magazine articles, consumer reports, books and manufacturers' specs. For our purposes, your system, no matter how big or how small it may be, breaks down into three main divisions: the first of these is a group of parts we will classify as the signal sources; the second, amplifiers, and the third, speakers.

Signal sources are pieces of equipment from which the program material running through the system originates. The various types of equipment that you might have in this category are: 1) the tuner; 2) record player; and 3) a tape machine.

Tuners

There are three types of tuners in common use: the FM, or frequency modulation type; AM or amplitude modulation, and AM-FM, which combines the two in a single unit.

Most hi-fi units that include radio reception are equipped to cover the FM band, either in the form of a straight FM tuner or an AM-FM combination. Since FM reception is so far superior to AM, AM tuners as separate entities are relatively uncommon. Consequently, an AM tuner as an individual unit is most likely to show up on the AM side of a two-channel stereo receiver system.

In recent years, due to the widespread use of printed circuits, miniature tubes and miniaturized parts, the size of tuners has been considerably reduced over the early models. In the early days of hi-fi, it was not uncommon to find a tuner measuring 13 to 15 inches wide, 7 to 10 inches high and 10 to 12 inches deep. Any

Fig. 101. There are two basic ways of mounting a tuner within a cabinet: (a) tuner mounted horizontally; (b) tuner mounted vertically.

Fig. 101. There are two basic ways of mounting a tuner within a cabinet: (a) tuner mounted horizontally; (b) tuner mounted vertically.

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reduction in height or width of tuners simplifies cabinet installation since it reduces the amount of control panel space required by the unit. Considerable reductions, particularly in height, have been made in the physical size of tuners. Tuners are now made in such a way that heights of over 4 y2 inches are relatively uncommon. This has made it possible to stack tuners and amplifiers, resulting in extremely compact control panels.

Tuners tend to get warm in operation. This is normal and does no harm as long as adequate ventilation is supplied. In most cases, providing adequate ventilation for a tuner is not an elaborate procedure. Try to allow about 1 inch between the tuner and any other electronic part next to it in the same compartment or, if other parts are to be mounted over the tuner, try to allow approximately 3 inches. Preferably, leave the back of the cabinet compartment housing such parts open so that air can circulate in and out freely. It is also a good idea, where possible, to drill a series of holes, say 1 to ly2 inches in diameter in the shelf on which the tuner is mounted to allow air to circulate up from underneath.

Most manufacturers state that their tuners can be mounted either horizontally or vertically; that is, with the controls facing either front or up (Fig. 101). However, my experience indicates that horizontal mounting, where possible, is definitely preferable. It seems to me that when I have mounted tuners vertically, they tended to burn out tubes a bit more rapidly. This apparent shortening of tube life is probably caused more by what the vertical mount does to the ventilation than by what it does to the tube orientation, since the vertical mount obviously requires that the tuner be brought up very close to the top panel, where there is very little space for air to circulate adequately. And, to make matters worse, generally the hottest parts such as the power transformer and rectifier are at the back of the chassis which in the vertical position becomes the bottom (Fig. 101-b). Their heat will therefore rise all the way up the chassis when it is placed vertically.

It makes no difference from the point of view of furniture installation whether the tuner is FM only or AM-FM except that the AM-FM tuner is generally somewhat larger than the FM only, has more tubes, generates more heat and therefore requires a bit better ventilation than the FM.

It would seem to be so transparently obvious as to be unworthy of mention that a tuner and its associated control panel should be placed in the cabinet in such a fashion that the tuning dial can easily be read, but you'd be surprised how often this little consideration is ignored. Easy visibility of the dial is one of the major reasons advanced in favor of the vertical mount for a tuner. Personally, I feel the disadvantages outweigh the advantages in this case.

Record players

Your second important signal source is the record playing device. It may be a record changer, a manual record player or a transcription-type turntable with a separate arm.1 Unless you have a large tape recorder, the record-playing mechanism is likely to be the largest single component in the entire system in terms of the cubic volume of space required for installation. It will therefore influence the overall dimensions of your cabinet more than any other single part. Although a number of manufacturers (both domestic and foreign) have record changers on the American market, the overall sizes are remarkably close. They will vary in height from about 7% inches overall to about 8i/2. In width they will range from 14i/£ to as much as 15i/£, and the largest variations will occur in depth, which may be from to 15i/£ inches.

1 Do not confuse the transcription turntable and the manual record player. The turntable is a high-quality professional unit. The manual record player is considered by many to be more suitable than the changer, but it nevertheless cannot be classed with a true turntable.

Fig. 102. for fixed installation of a record changer, a mounting board is used. It can be obtained precut for various makes and models of changers or can be made with templates supplied by the manufacturer.

Record changers can be installed in cabinets using a mounting board in which an irregularly shaped hole is cut (Fig. 102). The record changer is passed into this hole from above in such a fashion that the main plate, turntable, spindle and arm stand above the mounting level, while the motor and various levers and cams associated with the change mechanism hang down below (Fig. 103). Record changers are supplied with either three or four spring shock mounts through which they are bolted to the mounting board. Every model of record changer requires a different

  1. 103. Side view of a typical changer on a mounting board. Note the spring shock mounts.
  2. 103. Side view of a typical changer on a mounting board. Note the spring shock mounts.

shaped hole in the mounting board, but this constitutes no problem since every changer comes from the manufacturer accompanied by a template showing the shape of the hole required. The changer, on its mounting board, is installed in the cabinet by being set at an appropriate depth under a lid in a fixed position or attached to the top of a sliding drawer (Fig. 104).

The clearances required above mounting level for record changers vary between 514 and 5y4 inches. I generally allow a flat 6 inches. The clearance required below varies from 214 to 2 y4 inches. I generally allow a flat 3 inches, or a total of 9 overall.

Record changers, when not in use, must be kept covered by closing the lid or drawer, as the case may be. If they are left open, dust will accumulate on the turntable and be transferred from there to your records, causing unpleasant popping sounds as the record is played and also excessive wear on both the stylus and record.

When record players of any kind are installed in a fixed position under a lid, it is wise to allow a little extra space around the machine, if possible, so that it is easy to reach the controls, to place the stylus in playing position and to get records on and off the machine. In the case of a record changer placed in a drawer, be sure that you have a long enough traverse so that it will pull out far enough for convenient operation.

Beyond being sure that you've allowed enough space around the machine for convenient operation, a record changer requires no particular consideration in connection with cabinet installation. However, it must be fairly easy to remove for servicing.

Fig. 104. Two ways in which a changer can be installed in a cabinet: (a) mounted under lid; (b) mounted in drawer.

Turntables

The transcription turntable and arm will require more space in either length or width (or both) than a record changer or manual player. It will not usually require any more height. A turntable is a considerably more precise instrument- than a record changer in that it keeps more accurate speeds and it requires somewhat more careful installation.

Turntables are generally accompanied by a separate tone arm which holds the cartridge. This arm is often made by a manufacturer other than the one who made the turntable. It is essential in mounting an arm that the manufacturer's instructions as to the

Fig. 105. When mounting a turntable and arm, the distance between the pivot point of the arm to the center of the turntable is critical.

distance required between the center of the spindle of the turntable and the pivot point of the arm be followed with extreme accuracy. Where the arm is placed relative to the turntable is not usually important so long as the critical distance between the center of the spindle and the pivot point of the arm is observed (Fig. 105).

Since most floors are not quite level, it is necessary to level the turntabie mounting board after the cabinet has been put in its position in the room. This leveling becomes particularly important due to the fact that most turntable and arm assemblies utilize much lighter stylus pressure on the record than changers and, if the turntable is not level, the stylus and arm will not track accurately (Fig. 106).

While the overall height required for mounting a turntable and arm is no greater than that required for a changer, the heights above and below mounting level are different. Much less height is required above mounting level, and more below, than for the

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Fig. 106. When a cabinet is not level, the turntable can be adjusted by inserting a shim betucen the mounting board and the cleat supporting it.

changer (Fig. 107). I generally average them out at 3 inches above and 6 below instead of the 3 below and 6 above that I use for the

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Fig. 107. Because pf their construction there is a difference in the mounting level of changers and turntables: (a) room required for changer; (b) depth ?ieeded for turntable. Note that the overall depth is the same for both.

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  1. 107. Because pf their construction there is a difference in the mounting level of changers and turntables: (a) room required for changer; (b) depth ?ieeded for turntable. Note that the overall depth is the same for both.
  2. The actual depth below mounting level required for a turntable may vary from 4 to 5y4 inches, and the height above from 2 to 2y4 inches.

When some low level magnetic cartridges are used (particularly stereo) annoying hum can be induced in the pickup by power transformers up to 18 inches away. Make sure that the turntable and amplifier (or any other equipment using a power transformer) are far enough away from each other to prevent hum pickup.

Occasionally a turntable with a particularly large motor may require a little more depth below mounting level than the average 6 inches, so it would do no harm for you to check the one that you have in mind to be sure that it will fit in the average space and, if not, allow the additional depth required.

The length and width requirements of a turntable and arm assembly are determined partly by the size of the turntable and by the length of the arm being used. Some of these arms have an overhang of 3 to 5 inches beyond the pivot point, so you have to be sure that you have sufficient space for this arm overhang to swing freely to allow the cartridge to traverse the entire playing area of the record (Fig. 108). A fairly good average space for turntable and arm assembly would be a surface about 18 x 22 inches. A large number of the various possible combinations will fit on this space; some will require less and a few odd ones will require more. The space requirements for these units are far more varied than for record changers, and you should check in each case to find out what your exact needs will be.

The one other remaining consideration in connection with turntables is that, since they have considerably larger motors than record changers, they require better ventilation. It is advisable to have either 2 or 3 inches of air space below the motor in the cabinet, or to open the back of the cabinet from the level of the mounting board down to allow air to enter and circulate around the motor. Some turntables have a small fan either inside or outside the motor, attached to the lower end of the drive shaft. If your motor happens to be one of this type, you can get away with a bit less space in the motor compartment. But, in general, too much space is far preferable to too little.

Tape decks and recorders

Quite a few tape mechanisms are available, both of domestic and foreign manufacture. Many are made for tape playback only, others with both record and playback functions. You may or may not have tape at the present; the chances are good that, in the future, you will want it. It gives a kind of flexibility to your musical library that you can't get any other way and, of course, affords you an opportunity of recording miscellaneous material not commercially available that is of particular interest to you.

Unfortunately, however, tape machines are rather difficult to deal with in a general way as regards dimensions and cabinet mountings. They vary considerably in size, and they also differ in that some can be mounted vertically while others must be mounted horizontally. The size range runs from quite compact units that will fit in approximately the same space as a record changer, to the large, professional type units, some of which are pretty huge.

A good many tape recorders come in luggage cases, and a lot of people leave them in these cases with the idea in the back of their minds that they're going to carry the thing around a great deal to record material outside the home. It usually turns out that they don't but, by the time they find this out, they've already housed the rest of their equipment and their tape machine sits around the living room in its luggage case, becoming a bit of an eyesore. One solution, if you really think you're going to carry your tape

overhang does not hit the cabinet side before the cartridge arc can traverse the playing area of a record.

where you can put it, luggage case and all. If you decide to do this, the whole procedure is quite simple. All you'll have to do is measure the outside dimensions of the case and these will be the inside dimensions of the compartment you'll need. And you don't have any installation problems except to leave holes in the compartment for leading wires to and from the rest of your system.

Many, but not all tape machines come in cases; a number are made specifically for mounting in furniture. The procedure for mounting is very similar to that for mounting a turntable. You have a mounting board set at the proper height. In most cases 2 or 3 inches above and 6 or 7 inches below mounting is plenty of room. You can cut a hole in the mounting board to the proper shape, as shown by the template supplied, drop your tape machine through the hole, and bolt or screw it in place. If you have a unit that is cased, but you are willing to admit at the outset that you really aren't going to carry it around, then the best thing to do is to take it out of the case and proceed in the same way as for an uncased unit. Your system as a whole is generally cleaner and bet-ter-looking this way, and it usually gets better ventilation.

When you start measuring the unit to find out how much space you need, don't make the mistake that is often made—of measuring it without the reels. Before you start, put on a pair of the largest reels that the machine will take, and measure your dimensions outside of those reels. Otherwise the reels will get in the way every time you try to close the lid or drawer.

Most tape machines have a fan attached to the lower end of the drive shaft of the motor to provide air circulation. If your machine has more than one motor, this fan will be at the bottom of the main drive motor. If there is a panel of any kind close below the motor, try to cut a hole in the panel about the size of the fan. This will greatly facilitate the cooling of the entire unit.

If you have a machine that mounts vertically, just leave the back off. In this way you will get excellent ventilation with no trouble at all. In general, plan to give a little more consideration to ventilation of a tape recorder than is necessary in the case of a turntable. The machine is more complicated and generally has electronic parts closely associated with the mechanical parts, thus generating more heat.

The last signal source that we will note is the audio end of your TV. Why many people insist on piping their TV sound into the hi-fi system is more than I can quite understand. Most of what you listen to on TV is speech, and it doesn't require a very high fidelity system to reproduce intelligible speech. After all, the telephone company reproduces an awful lot of intelligible speech through equipment with a frequency response range running from 100 to 3,000 cycles. On hi-fi, you're shooting for frequency response ranges of about 20-18,000 cycles. It seems to me that to use your hi-fi system for TV sound is a bit like shooting cannon balls at flies, but there are those who insist on doing it. If all you want to do is run your TV sound from the TV receiver, wherever it now is in the room, into your system, that, of course, does not involve any cabinet considerations. All you have to do is have an audio takeoff installed in the TV set, and run a cable over to your amp or preamp.

Where you run into cabinet considerations is when you have decided to put your TV in the same cabinet with your hi-fi system.

Unless you have one of these new little portable jobs, your TV is probably a pretty large unit. It will considerably increase the overall dimensions of your cabinet not only in length, but very likely in depth. Often a system that normally requires a cabinet about 18 inches deep overall, suddenly becomes 24 inches deep when you add the TV. This is the point where you should stop and consider whether your room is big enough to take a cabinet of that size and depth. I have often seen rooms completely overpowered by the size of the cabinets that resulted from the incorporation of TV's with complete hi-fi systems. I cannot caution strongly enough against this way of doing things, except in very spacious rooms.

Amplifiers

Your amplifier will generally consist of two main sections. The first is the preamplifier or control amplifier and the second is the power amplifier. Depending on size, power and type of construction, these two may be together in one unit or physically separated. Today, amplifiers of medium power (10-20 watts) are generally on one chassis while the larger, more powerful ones come in two parts or sometimes even in three (Fig. 109).

Let's look at the smaller amplifiers first. In general, combination preamp-amplifiers are now being made in sizes and propor

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tions roughly similar to those of tuners. They may be fairly wide and deep, but not very high. As with tuner construction, this type of amplifier represents a considerable departure from earlier models which had more height. This change in construction tech niques tends to make both tuners and amplifiers much easier to mount in cabinets. In a slightly larger space than was formerly required by either a tuner or an amplifier, it is now possible to stack both of them, one on top of the other, making the entire equipment compartment modest in size and the control panel quite compact (Fig. 110).

A large number of the smaller amplifiers can be easily accommodated on a control panel no more than 161/4 inches wide by 12 inches high, with space to spare. Actually, very few of the flat amplifier chassis run more than 13i/2 inches wide, and a few of the smaller ones are as narrow as 9 or 10 inches in width. Heights range from 3i/£ to 4i/2 and in depths range from 9 to 12 inches.

Where flat tuners and amplifiers are mounted one over the other in a compact compartment, it doesn't matter which one you put on the top. That is determined by your own taste. Installation of parts in such cases is very simple. Templates for the holes to be

Fig. 110. Pancake type tuner and amplifier mounted horizontally in a cabinet. Stacked mounting is one of the conveniences provided by flat construction.
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