Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!usc!elroy.jpl.nasa.gov!lll-winken!uwm.edu!csd4.csd.uwm.edu!info-high-audio-request
From: bms89@ecs.soton.ac.uk (Scally BM)
Newsgroups: rec.audio.high-end
Subject: Re: Need power regulator recommendations
Message-ID: <13454@uwm.edu>
Date: 26 Jun 91 12:58:15 GMT
Sender: news@uwm.edu
Lines: 52
Approved: tjk@csd4.csd.uwm.edu
Originator: tjk@csd4.csd.uwm.edu


 I'm about to ramble again.....

 In my opinion most powersupplies are very capable of coping
 with LF modulation of their source (mains). The harmonics
commonly incountered due to hystersis in the core are again
at relatively low frequencies up to about 5th at low levels.
 HF noie- due to the increased use of switch mode powersuplies
and the surges caused by diode conduction present lots of HF noise.
 Standard powersupply electolytics are not that good at handeling
this.

 Thus in a well built amplifier there will be devices to remove the
HF noise thus preventing it from causing distortion to the signals.

 So far so good... no flames yet???

 Due to cost cutting pre transformer hf filters, and post transformer
bypass filters are often left out.

 Consider the specifications though..

 This devige has to 'repell' noise down to 7K (at low levels
 at the bottom frequency) yet be capable of responding to
current transients at up to 20K. Hummm

 A tad of a design problem I fancy.

 Any help will of course benafit the sound but to much control
will strangle the life out of the system.

  QUERIES

 Has anyone ever tried there system on it's own generator??

  Sugestions..

 A device that filters and rectifies the mains and then
modulates it at a constant frequency (50/60hz) with
enough power to run an amplifier (or two..) you are right
this is getting silly. Such devices are available..
for turntables as well...

 Why not just go and get a nice line from the electricity
board... remove nasty transients on the way to a good size
transformer, nice not to noisy diodes, good smothing
and there you are. with a good powersupply. and hopefully
good sound.

  That is how it should be but for economies....

 Tigger