Buffered Pre-out? What is it?


I have a preamp that has a "normal" pre-out for short IC's and a "buffered" pre-out for long IC runs (not balanced). I assume the buffering is to keep noise down. What is the electronic or operational concept behind this type of buffering? Anyone know?

Thanks and Best Regards,
Jim
stilljd

Showing 2 responses by mlsstl

You don't say what make and model of preamp is involved. Buffering in an analog circuit is usually done to make a circuit more tolerant of difficult load situations. (This is different than digital buffering, where data is accumulated in a memory chip and then parceled out to a device or program as needed.)

In your case it sounds like the preferred circuit is the unbuffered one, but that it doesn't tolerate the added resistance or capacitance of a long interconnect. In that case, the extra stage of devices (the buffer circuit) may offer the better compromise in terms of sonic degradation.
> Sometimes it requires more circuitry which adds another
> stage, some feel the shortest route is the best.

There are a number of equipment designers who believe that a simpler circuit design is better on the basis that the fewer components a signal must pass through, the better. This is the same reason that some electronics invert the phase of a signal. They could easily add one more stage to not invert, but feel the extra circuitry isn't worth the sonic cost.