And you do it so that it does not burn out. But for this, it is necessary to have optimal stability margins both in phase and in amplification, including on a reactive load. And then if it burned out for you, then your amplifier will burn out for everyone who undertakes to repeat it. As they say: it is difficult and a fool will come up with ...
You're right, it has nothing to do with the JC-3 amplifier. This is one of the first developments by John Curl. Today, many are not satisfied with low power and high energy consumption (low efficiency). Therefore, I tried to modify the circuit as much as possible while maintaining the low switching distortion characteristic of class A. This is what class A amplifiers are made for.
I want to end my deviations from the original with another simple test.
Cortez showed distortions occurring at the beginning and at the end of a burst with a frequency of 10 kHz.
https://www.diyaudio.com/forums/solid-state/366099-musings-amp-design-thread-split-post6519124.htm
Musings on amp design... a thread split.
Let's see how the signal with a frequency of 20 kHz is amplified.
One picture shows three synals:
output signal (red);
input signal reduced to the output level by multiplying by Ku (black) - ideal output signal;
input signal delayed by the time tPD and multiplied by Ku (blue) - the signal to which the output signal tends
Another figure shows the initial stretch of a sinusoid.
The third figure shows the burst and the result of subtracting the output signal from the delayed input signal - the actual distortion introduced.
As in the example of Cortez, we see distortions at the beginning and end of the burst with an amplitude of 75 mV. This kind of distortion is called FCD by Graham Maynard.
The less the signal transmission delay, the less and the level of this type of distortion.
I want to end my deviations from the original with another simple test.
Cortez showed distortions occurring at the beginning and at the end of a burst with a frequency of 10 kHz.
https://www.diyaudio.com/forums/solid-state/366099-musings-amp-design-thread-split-post6519124.htm
Musings on amp design... a thread split.
Let's see how the signal with a frequency of 20 kHz is amplified.
One picture shows three synals:
output signal (red);
input signal reduced to the output level by multiplying by Ku (black) - ideal output signal;
input signal delayed by the time tPD and multiplied by Ku (blue) - the signal to which the output signal tends
Another figure shows the initial stretch of a sinusoid.
The third figure shows the burst and the result of subtracting the output signal from the delayed input signal - the actual distortion introduced.
As in the example of Cortez, we see distortions at the beginning and end of the burst with an amplitude of 75 mV. This kind of distortion is called FCD by Graham Maynard.
The less the signal transmission delay, the less and the level of this type of distortion.
