Amplifier 擴音機 / NAGRA / MSA

MOSFET Stereo Amplifier The MSA is a stereo power amplifier giving 60 Watts per channel into an 8 Ohm load. Its physical footprint is identical to the compact Nagra range, of CDC, VPS, PL-L and PL-P.


Unique design
The electronic design is inspired by the PMA / PSA amplifiers. The output uses a simple pair or MOSFET transistors, a solution that allows the purest and most transparent signal. The MSA is completely symmetrical from the input to the output.

To make the most of the limited surface area, the heat sink covers the entire top of the amplifier. It is machined from a solid 10 kg block of aluminum, and after machining is completed, its weight reduced to 3.5 kg! This elegant and unique solution allows the amplifier to keep a reasonable temperature even working at full power for a long time.


The front panel is quite simple with just the power ON selector and the world famous Nagra modulometer style power meter. An AUTO start / shutdown function is provided that will turn ON and OFF the amplifier in the presence or absence of input signal.

Pure power
The MSA is also designed to work as a monoblock. A bridge selector switch on the rear panel allows parallel bridging,and the MSA will then double the current at the output as well as the power. This allows better driving of difficult loads or simply increasing the power if this is needed, for a less sensitive speaker for instance.

The input sensitivity is switchable to 1 or 2V, by the means of switches on the rear of the amplifier, to offer the best match with the pre-amplifier.