Buffered Pre-out? What is it?

A buffer stage has a gain of 1 (or sometimes a slight attenuation). In general such a low gain circuit, either a tube (cathode follower) or a transistor, has virtually no distortion... certainly way less than the associated gain stages. A buffer output stage prevents signal deterioration due to loading of gain stages that have high impedance output, so it is puzling that the manufacturer says not to use it. Perhaps he is catering to those who believe that ANY additional circuitry is always bad. These folk ignore the loading effect on the "naked" gain stage.

> 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.

Viridian, Eldartford, Mlsstl,

Thanks a lot for the explanations.

A pre-out buffer lowers the output impedance. In the case of Arcam they provide this optional output to make up for a long IC run that could add to the impedance the amplifier sees? Yes?

A buffered output stage doesn't necessarily add distortion because it does not add gain. It may deteriorate sound quality because of the added circuitry?

It all makes sense. Arcam markets to HT and multi-room implementations. Remote equipment placements, long IC's and/or speaker cable runs.

Thanks, it has been a good day at the office (I learned something today!). I am going to try the buffered output to see if I can hear a degradation in sound.

Just curious.

Really, thanks a bunch for taking the time!

Jim S.