Scope Measurements

[Tranquility Bass]

Some simple power measurements on the Ultimate Amplifier using a scope. The first two channels are powered by a Hypex NCore NC502MP amplifier module which would typically be assigned to the low frequency channels in an active speaker system. This is the most powerful of all amplifiers in the Ultimate Amplifier with a name plate rating of 500 watts per channel into 4 ohms. We used the channel clipping indicators to determine the maximum power threshold before clipping but later on we will use the dScope III audio analyzer to accurately measure the power output at a given THD level and show how conservatively rated these amps really are The results will shock you at how powerful these amps really are and how well designed the switch mode power supplies are to maintain tight regulation and almost doubling power into 4 ohms

Continuous 1KHz Sinewave into 4 ohms before clipping with one channel driven corresponding to 595 watts into 4 ohms.





Continuous 1KHz Sinewave into 8 ohms before clipping with both channels driven corresponding to 321 and 317 watts respectively.





Full Power 20Hz Tone-burst with 1 to 5 duty-cycle (5 cycle on 20 cycle off) single channel into 4 ohms





Full Power 100Hz Tone-burst with 1 to 5 duty-cycle (5 cycle on 20 cycle off) single channel into 4 ohms





Full Power 1000Hz Tone-burst with 1 to 5 duty-cycle (5 cycle on 20 cycle off) single channel into 4 ohms





Top Trace = Full Power 100Hz Tone-burst with 1 to 5 duty cycle with 5 cycle on 20 cycle off single channel into 4 ohms
Bottom Trace = Current measurement of voltage across a 0.1 ohm sense resistor (20 amps per division)





Full Power 1000Hz Tone-burst with 1 to 5 duty-cycle (5 cycle on 20 cycle off) single channel into 8 ohms





Continuous Sinewave at 1000Hz After Clipping with both channels driven into 8 ohms

[Tranquility Bass]

Testing the clipping indicators. The Hypex amplifier modules can assert their channel clipping flag if the output of the amplifier exceeds either a set voltage or current limit. The clipping flag from the Hypex amplifiers are non-latched which means we need to latch the clipping flags in hardware otherwise the software could miss it if it is relying on polling. As a result each channel can report the clipping status in real time by making the LED turn red for at least 100mS so it can't possibly be missed by the user. This tells the user that amplifier is being over driven and the level should be reduced !

Scope image of the first two channels of the amplifier being driven into voltage clipping.




Indicator LEDs turn red when its respective channel is being over-driven into clipping thus signalling to the user to reduce the level !