Tuning Tips from M to P

Mains Polarity

Correct mains polarity can noticeably improve the sound of a hi-fi component. Why? When connected correctly, the live conductor feeds the inner end of the transformer's primary winding. This reduces capacitive coupling from the transformer to the equipment enclosure. Since that enclosure surrounds the electronics, it is easy to imagine some of this energy being added to the music signal. The following procedure using a multimeter has worked well for me:

• Disconnect every connection from the device under test.
• For a Schuko plug, temporarily insulate the protective-earth contacts for the measurement.
• Set the multimeter to AC voltage and measure between the enclosure and protective earth.
• The plug orientation producing the lower voltage is the correct mains polarity.

This procedure should be carried out for every device connected to a wall outlet.

Nickel

Nickel is widespread in the audio industry. It is used mainly as a barrier layer beneath gold, silver or rhodium plating on plugs, sockets, switch contacts and similar parts. It can be polished very well, making the subsequent gold layer look particularly shiny. Nickel is also found in the terminations of resistors and other electrical components. Whether the problem is the element's ferromagnetism or some other property, one thing is certain: nickel sounds b ... ad.
Only a few manufacturers avoid nickel in their plugs, sockets and switches. I therefore routinely use a strong neodymium magnet to check whether the promised absence of nickel is actually true.

(Leave It Switched) On

I recommend this with a slightly guilty conscience because we must also consider the environment. Perhaps it can at least be an incentive to switch to a renewable electricity supplier.

If an audio component is left switched on continuously, its sound quality can improve markedly after a few days. The bass becomes lean and precise, and the entire system plays exactly on point. The mechanism is easy to explain:
The continuous voltage and current help form the electrolytic capacitors inside the equipment. They then operate more effectively and with less leakage current, which improves the sound. This can also extend the service life of the equipment, because continuous operation is not what ages a component most; repeated switching on and off does. This does not, of course, apply to valve equipment, where tube life is the overriding consideration. Source components should consume little enough power to make leaving them on for a trial week practical.