We got into a vigorous discussion of power supply regulators in the Pass P3 Phono Pre thread. (The P3 uses 7815/7915's) To avoid "thread-jacking" detracting from this really nice design by Wayne, I thought it would be appropriate to start another thread. https://www.diyaudio.com/community/threads/pearl-3-burning-amp-2023.404054/
Pick your continent and you've already experiencing 50/60Hz and 100/120Hz on the rails...but there are other nasties which do impair the quality of sound. One of those is the distortion that a regulator error amplifier can inject onto a preamplifier. This was pointed out by a correspondent to the LinearAudio article commenting upon the article comparing various regulator topologies. I did as suggested and le voila, the LM317 (which rated poorly) did have a THD component when a 1kHz signal was injected into the error amplifier.
There's also the issue with reverse PSRR discussed in this paper from Omicron-Lab: https://www.omicron-lab.com/fileadm...e_Transfer/App_Note_Reverse_Transfer_V2_0.pdf When a number of regulators talk to each other there may be problems!
Pick your continent and you've already experiencing 50/60Hz and 100/120Hz on the rails...but there are other nasties which do impair the quality of sound. One of those is the distortion that a regulator error amplifier can inject onto a preamplifier. This was pointed out by a correspondent to the LinearAudio article commenting upon the article comparing various regulator topologies. I did as suggested and le voila, the LM317 (which rated poorly) did have a THD component when a 1kHz signal was injected into the error amplifier.
There's also the issue with reverse PSRR discussed in this paper from Omicron-Lab: https://www.omicron-lab.com/fileadm...e_Transfer/App_Note_Reverse_Transfer_V2_0.pdf When a number of regulators talk to each other there may be problems!
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Well, on my PS rails is either low noise or harmonics under load from amplifier. Beside rails noise and harmonics under load, we should measure transient response with square wave load.
Rail harmonics here are consequence of amplifier pulling power for 1 kHz output signal, not obtained by injecting signal to voltage regulator's error amplifier.
Rail harmonics here are consequence of amplifier pulling power for 1 kHz output signal, not obtained by injecting signal to voltage regulator's error amplifier.
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I use a discrete transistor regulator with a topology similar to an audio amplifier, followed by RC filtering, powering a discrete transistor pre-amplifier with high PSRR.
I developed the circuit for my power amplifier. The pre-amplifier re-used it at lower voltage.
Ed
I developed the circuit for my power amplifier. The pre-amplifier re-used it at lower voltage.
Ed