Author Topic: Common Power Supply, Feedback Between Stages  (Read 1820 times)

Offline steve

  • Audiologist
  • *
  • Posts: 1238
Common Power Supply, Feedback Between Stages
« on: September 13, 2018, 01:43:43 PM »
In this October, 1997 White Paper, I discuss the problems of using a common power supply for all the stages in a component.

In short, musical signal information is fed back from stage to stage(s) through the power supply filtering stages. Another reason why your stereo system does not sound natural/accurate.

Since the power supply capacitors have AC resistance/reactance, the amount of unwanted musical signal fed back is frequency dependent as well. The lower the frequency, the greater the amount of unwanted feedback, with phase shifting.

The best solution, of course, is to use a separate power supply for each stage. However, some designs, such as the phono stages cannot feasibly use separate power supplies for every stage. In such cases, care must be taken when designing the power supply.

Here is the link.

http://www.sasaudiolabs.com/theory8a.htm

Cheers

steve


« Last Edit: September 13, 2018, 02:09:20 PM by steve »
Steve Sammet (Owner, Electron Eng, SAS Audio Labs, Ret)
SAS "V" 39pf/m 6N copper ICs,
SAS Test Phono Stage
Acutex 320 STR Mov Iron Cart
SAS 11A Perfect Tube Preamp
SAS 25 W Ref Triode/UL Monoblocks
2 way Floor Standing Test Speakers