crown ma10000

[d3imlay]

I was doing contract tech work for SoundValves when they sold these amps. I tested them before they shipped out. Output was only 54 volts as I recall. However they would go down to .5 ohms or so. Do the math. The versions I saw were the gradient drives. I understand they drove the X/Y fields in an MRI.

I used one as a variable frequency source driving a stepup xfmr. I could get 5KW at 45-65hz/240 volts. I did blast the amp a couple times, I think due either to kickback from the xfmr or the low power factor. I pulled the defective transistor out and kept on going. In their original application they had something like a .05 ohm 250 watt resistor in series with the output. The tech manual showed how to series/parallel these amps for more voltage/current.

The design was an H bridge. 4 "wells" as Crown called the heatsinks. Seems like each well had 20 TO3's. You can run these single phase 208/240 but you have to mod the power supply board. Of course output power would be reduced to less than 50%.

[SOSamp]

I have a Crown sales pamphlet that states weighs 128 lbs and is designed for loads under 1 ohm. No wattage specified. I believe it put out 1KW at 8 ohms. No list price specified, but I think it was $10,000.00. There is no date on the pamphlet.