Bel Canto Design SET 40 manual Amplifier Power and Loudspeaker Selection

Amplifier Power and Loudspeaker Selection

The SET 40 has a nominal power rating of 37 watts for each channel. While this may seem like a low power output compared to many amplifiers on the market, because of the class A operation, the low distortion, wide power bandwidth, and the grace that these amplifiers have when overdriven, they will produce as much or more level sound than many 100 watt amplifiers. We suggest that you consider any loudspeakers with average rated sensitivity of 86-87 dB/Watt/Meter or greater. Greater

sensitivity will allow higher listening levels before either the amplifier or the loudspeaker runs out of steam. Remember that with many speakers in even a relatively large room the amplifiers will be operating at average levels of only 1-5 watts each with typical music at quite a high average sound level of 90 dB. This leaves 15 to 17 dB of amplifier headroom for musical peaks.

We have successfully used the SET 40 with many types of loudspeakers, including dynamic cone, planar magnetic and electrostatic types. When choosing a loudspeaker many variables come into play, therefore we will not attempt to recommend a type or set of 'brands' which you should consider. Our suggestion is that you work with the dealer representing the SET 40 and choose a loudspeaker which works well for your tastes, in your room with your system. A dealer which sells the SET 40 will be more than competent to guide you in your selection.

Amplifier Placement and Power- on

When installing the amplifiers it is important that they receive adequate ventilation. Allow at least 6 inches above the amplifiers, and be certain that the holes on the bottom cover are open to air circulation (do not place them directly on a thick carpet, as this will block the bottom ventilation holes). Do not use the SET 40 in a closed cabinet unless fan cooling is allowed or the amplifiers will overheat and could be damaged. They generate consider-able heat in operation because of their single-ended class A operation. With adequate ventilation on an open shelf or stand they will cool themselves through convection and will not require any additional cooling.

When the setup is complete and all connections are made, the power cord can be installed and the power switch turned to the 'on' position.

The amplifiers will be operational nearly immediately, and they require only 15 to 20 minutes to reach optimum performance. There will be a short break-in period of 20 to 30 hours when the amplifiers are first used. The sound quality potential will improve during this period as all of the components and tubes 'settle in' during this time. Further improvement in sonic performance will occur during the first 100 to 200 hours of use as the copper wire anneals and all of the components settle in.

Page 8 SET 40 Owner's Manual