>-----Original Message----- >From: Ken Javor [ mailto:[email protected]] >Sent: Wednesday, May 14, 2003 10:55 AM >To: [email protected]; [email protected] >Subject: Re: commentary on the use of recent model McIntosh amplifiers >for audio susceptibility testing > > > >There was a solid-state model that was 200 Watts per channel >into 8 Ohms but >a lot more than that into four, and they also specified power >into 2 Ohms, >and it was huge. What you want is the ability to drive 2 >Ohms, because the >0.5 Ohms that the signal is calibrated into reflects as 2 Ohms >through the >injection transformer. It might have been an MC2120; but for >sure it was >solid-state and about $700 used. You also want huge power >rating, because >dspite what they tell you, the rms power that these amps can >produce is for >short periods of time. If you need to run 50 or 80 Watts for >extended time >periods, the heat sinking better be rated for hundreds of Watts. > >Here is a great website for used Mcintosh, it is for guys what >a shoe store >is for women... > > http://www.mcintoshaudio.com/ >
Ken is right to point out that the old Solar amplifier may be rated for 100 watts, but not for very long! I have found that, even trying to deliver 80 watts continuously, you will run into thermal self-protection shutdown. Be careful not to stack the Solar next to a scope which is pumping out hot air. Fortunately, tripping the thermal overload is only inconvenient; no harm other than the surprise and delay. So, even if you have a specification maximum power limit, it's nice to have a lot more power in reserve. I have recently read about new developments in the design of high-power AF amplifiers for automotive applications (those obnoxious monster auto stereos). I believe the talk was about using (IIRC) Class D operation, and compactly achieving very high power and di/dt rates. I wonder if these amplifiers might be adaptable to our conducted immunity amplifier needs? Those McIntosh amplifiers are too expensive for me. Regards, Ed Ed Price [email protected] NARTE Certified EMC Engineer & Technician Electromagnetic Compatibility Lab Cubic Defense Systems San Diego, CA USA 858-505-2780 (Voice) 858-505-1583 (Fax) Military & Avionics EMC Is Our Specialty
