HiFi Component Essentials.....Power Amplifier.....Pre Amplifier.....Inputs.....Connections
For reasons mentioned elsewhere (Speaker Technical), your speakers are THE most important and sound CRITICAL part of the system. No matter how much you spend on other component parts, the speakers translate this into what you actually hear. A good quality pair of Point Source speakers can transform your existing mediocre system into something spine tingling. Putting a poor quality pair of speakers (even if wildly expensive) onto your state of the art system will (if you are honest) sound disappointing at best and really naff generally.
So the moral is to buy the best speakers (even at the expense of the rest of your system) you can possibly afford and upgrade other parts of the system as finance allows. This approach gives you the best quality of sound over your hifi career, especially when you are younger and have the quality of hearing to fully appreciate the subtleties of the higher frequencies that go AWOL later in life.
What makes a good speaker?
- It has to be a Point Source design (ie Dual Concentric)
- It should have a ruler flat frequency response and well defined -3dB cutoff frequencies
- It should be low distortion (<1%) over the whole audio bandwidth
- It should be well made - implicitly quite heavy and should sound "dead" when tapped ie well damped cabinet
- High sensitivity - hence less stress on the amplifier and louder
- Should be able to comfortably deliver enough volume given the size of drive amplifier
- Should be an easy load for the amplifier and not cause instability
Sub Bass Speaker
- Should be solidly built - Heavy
- Should extend the low frequency range of your main speakers and be tailored to fill in the frequencies missing
- Can be placed anywhere in the listening space (omnidirectional)
Power Amplifier Essentials.....Back to Top
What makes a good power amplifier? Essentially:
Item (2) above will depend upon your speaker sensitivity, size of room (ie distance between listener and speaker) and the sheer volume you wish to achieve.
- No audible hum, noise or distortion at any setting
- Enough power to run at or below 90% of rated power for any program
- No switch on or off noises
- Precise volume settings with exact channel matching at any volume setting
- Completely ineteference free
- Ruler flat frequency response over a range wider than the accepted audio spectrum
- Should be able to drive any speaker load without instability
- Should cope with overload and be speaker short circuit proof
Item (5) above is critical to the soundstage remaining central at any volume setting. If the Saxaphone for example moves 2' to the left (or right) when played at loud volume but remains centerstage at lower volumes then you will realise how important this is! Getting this parameter right can be very expensive but is solved by having either a high quality clicked attenuator or by a multi stepped digital attenuator where the L+R values are critically matched within the attenuator chip itself. This can be difficult to achieve.
Item (6) above is absolutely critical to the overall pleasure of using your system. Any interference, be it the fridge switching on/off, a lightswitch, the central heating or a taxi going past that is audible on your system is a product of either bad design, poor interconnects, bad earthing or high impedance input circuits. All sources of interference should be ruthlessly tracked down and eliminated.
Pre Amplifier Essentials.....Back to Top
Much the same as the power amplifier and especially sources of noise and interference. The quality of input switching is also key.
Should be noise, hum and distortion free.
Connections Essentials.....Back to Top
Unless using balanced line or ultra low impedance - keep all interconnects as short as possible.
Use good quality cable - 100% foil screened for signals and gold plated plugs / sockets for audio low level connections.
Keep signal cables away from mains cables.
Make sure all mains connections (ie within mains plug) are tight - especially the earth connection.
Keep speaker runs as short as possible and use the correct gauge of wire.
Even if using unbalanced (signal + screen) signals for interconnects, wire up in pseudo balanced method (signal + 0V + screen) and connect the screen at one end (the input) ONLY. NB - Connect the 0V and screen together at one end.
If possible, arrange all outputs to be ultra low impedance and especially line level outputs - 75R or less - as low as possible to minimise interference and noise pickup.
Low impedance outputs (<75R) tend to be immune from the effects of cable capacitance, inductance or other losses.
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