Tuning Tips from I to L

Ideal-Diode Bridge Rectifier

This one is for dedicated DIY enthusiasts. Almost every audio component contains at least one rectifier, usually configured as a Graetz bridge. In normal operation, however, this bridge loses 2 x 0.7 V in forward voltage. Above a certain current, that represents a significant loss and requires cooling. With the LT4320, Linear Technology developed a controller that drives four MOSFETs in place of the four diodes. Because a switched-on MOSFET has very low resistance, extremely high currents can be handled with very little loss. My own experience agrees with reports in specialist audio forums: this IC sounds genuinely good. Is that because of the additional 1.4 V supply voltage? I suspect instead that the controller produces less transformer ringing. In my opinion, a snubber can be omitted. While researching this article, I even found a German amplifier manufacturer using these modules in its reference amplifier.

(Butyl-) Knead

Butyl putty is used mainly in the automotive industry to damp large sheet-metal panels. Legend has it that, after the automotive industry, a renowned German loudspeaker company is the second-largest user of this material. It is applied to damp drivers, internal wiring and crossovers. That loudspeaker manufacturer introduced me to the putty, and I have since used it to damp components and connectors. It can easily be rolled into a strip and wrapped around the joint between a plug and socket, or applied in many other likely and unlikely places. Its volume resistivity is greater than 10¹² ohm-cm, so it presents no electrical problem. It is also very effective at damping resonant equipment covers. Even after years, the putty can be removed without leaving residue. Here is a link to a supplier better known around the world for its screws.