Sound Advice: Older stereo amp can be updated with extra inputs

Q: We have a classic Yamaha A1 stereo amplifier that still works well. It is great for vinyl because of the direct connection to the power stage, which sends the signal straight to the amplifier for very clean sound.

Unfortunately, it has few inputs; all are being used, and we want to add more devices to it. What amplifier would you recommend with at least four inputs, selling for up to $400?

A: The Yamaha A1 is an outstanding amplifier, and you would have to spend a lot more than $400 to get something remotely comparable in quality. Fortunately, I have an extremely inexpensive solution that will allow you to keep using it.

You can buy a switch that will turn one RCA input into four inputs. They are readily available online and in stores for around $20 and usually include terminals for stereo audio and analog (non-HDMI) video. The Monoprice 3027 is a great one, and it learns remote commands as well. See it at monoprice.com.

Q: Why are headphones marked for the left and right ears? Do the left and right ears hear differently. For example, does being left- or righthanded affect an ear as being dominant?

With digital and all the advancement in sound technology, is it still relevant to have headphones marked left and right?

A: Your question about superior hearing in the specific ear being related to the dominant hand is better posed to a doctor or audiologist, although I admit you have piqued my interest and I will be doing some research on the subject.

When a stereo recording is made, there is a left side and right side. That is the meaning of stereo. Putting the headphones on properly ensures the recording is heard in the way the producer intended. If you put the headphones on backward, the stereo image will be reversed, so instruments meant to be on the right will be on the left, and vice versa.

It is easy to understand this concept if you use photography as an analogy. Imagine you are holding a 35mm slide up to the light and viewing it.

If you hold it one way, you are viewing the scene as it appeared in real life. But if you flip it around, things that were on the right would now be on the left. You would see a 100 percent accurate image with all the details present, but it would be reversed. That is what happens to the sonic image when you put headphones on backward.

There may be practical reasons to make sure your headphones are on properly, as well. Most people are righthanded, so the microphone and button are on the right to make it easier to control. This is the only right/left dominant reason for headphone design that I am aware of.