by Brewster LaMacchia | May 25, 2018 | Audio, Testing
This is the long delayed followup to the earlier post about power resistors as dummy loads and the nonlinearities found. After some further experimentation an 8 ohm load was built from four Riedon PF2270 series 2 ohm 200W thin film resistors (to give an 8 ohm load)...
by Brewster LaMacchia | May 25, 2018 | Audio, Design, Testing
As part of some ongoing work earlier this year I needed to test the performance of a high performance 200W/channel class D amp (more on the amp in some future post). To get accurate SNR and THD+N measurements a low pass filter is needed in front of the measurement...
by Brewster LaMacchia | Feb 5, 2018 | Audio, Testing
In the past only relative low power loads have been needed for the evaluation of monolithic class D amp chips as they are typically 25 watts and under. Now working with some 200W (8 ohms) – 400W (4 ohms) amps and beefier load resistors are needed. The following...