Shopping Tips continued..
Remember that the principal purpose of a receiver is to take a weak signal from a CD player or satellite receiver, etc., and make it powerful enough to produce sound from speakers. A receiver’s ability to do this effectively is largely determined by the quality of the power supply it uses. Better power supplies tend to be expensive and physically heavier, due to the use of heavier and better magnets in their construction. So pickup the receivers you are auditioning, and feel their weight.
Noisy Preamplifier Section
To build a quality product you need to use quality parts, which are more costly. So to keep the cost down, manufacturers can cut corners in areas such as the power supply and the speaker connections. Another area they can cut costs in is in the preamplifier section of the receiver, (remember a receiver is an all-in-box containing a tuner, power amplifier and preamplifier). In a perfect world, no portion of a receiver should introduce noise into the amplification process. So when the receiver is on, and you are sending no signal to it, you should hear noting. You can perform a simple check for this when you are in the store. Turn all sources (CD player, DVD player, TV, etc.) connected to the receiver off; turn the volume up about half way, if you hear a lot of white noise (hiss), the receiver has a noisy preamplifier section. Make sure you cycle through all of the input channels on the receiver to be thorough.
The concept of a speaker is very simple. It uses an electromagnetic device to create a vibration that produces waves of alternating pressure. The way that speaker manufacturers achieve this is highly varied and at times complicated. As the old saying goes, “there is more than one way to skin a cat”. There is a lot of variability in the way speakers perform, so when you are auditioning receivers, try to be consistent and listen to the same speaker with each receiver. If you are intending to also purchase speakers with your new receiver, try to audition receivers with those speakers. If you will be using speakers you currently own, dig out the manual that came with it and find the sensitivity rating measured in db. Try to audition receivers using speakers with the same sensitivity. If you audition receivers using different speakers, the speakers with the higher sensitivity rating will produce a louder output level when driven by the same amplifier. You need to ensure that the playing field is as level as possible during your receiver auditions.