Here’s a list of equipment we used to adjust, optimize and evaluate the performance of this amp. It is unlikely that the ultimate performance could be attained if any of these instruments (or equivalents) are not available….
The bandwidth was measured using the HP3562A spectrum analyzer using the Sweep Sine analysis mode. The result is presented in the image below...
The pulse response was determined by feeding a square wave from the PM5192 synthesizer and recording the response on the oscilloscope screen, with or without a capacitive load connected in parallel with the load...
The distortions were measured using the Amber 5500 instrument (THD+N) and the HP3562A spectrum analyzer (THD and IMD by CCIF and SMPTE methods). HP3562A has a dynamic range of only 86dB
The damping factor was measured by measuring the output voltage variation, while modifying a pure resistive load...
We investigated two clipping characteristics. Without a clipping protection, the amp behavior was really bad. The output parasitic oscillations are pretty common in a high feedback design...
The Ultimate Audio Amp
From Genesis to Revelation