From: chrisc@gold.gvg.tek.com (Chris Christensen)
Newsgroups: rec.music.synth,rec.audio.pro
Subject: Re: power conditioning?
Date: 16 Apr 92 20:30:38 GMT
Followup-To: rec.music.synth
Organization: Grass Valley Group, Grass Valley, CA

In article <1992Apr14.165335.25263@zip.eecs.umich.edu> 
ploot@eland.eecs.umich.edu (Larry David) writes:

>I've been thinking of getting a line conditioning plug strip for my home studio
>rack.  What do people use for this kind of thing?  I've seen Furman's line of  
>stuff, and the PL-8 and PL-plus seem like they would do what I want (although  
>I'm not sure exactly what I want)--are there any other similar products?  Aside
>from basic surge filters and fuses, how important are for example RF filters in
>terms of line noise; i.e. can you hear a difference with and without them on  
>the average U.S. residential AC line?  Filters for 60 Hz hum, fluorescent light
>noise, appliance pops and clicks etc...seem like a good idea, but I don't know 
>how effective/necessary these would be.  I have a very audible amount of noise 

The use of filters is intended to keep a noisy line from getting
through to the equipment. The average U.S. Res line...!  That is a
real open door.  Are you in a house on a block?  Is your house and the
one next door on the same transformer?  I think you see what I mean.
The incomming line to youe house could be "dirty"!

My opinion of these devices is that they are "...the rubber glove for a
leaky fountain pen....."  In other words a bandaid for another
problem.

The best solution for the line noise problem is a dedicated power line
directly from the power panel of the house/building that the studio is
housed in.  I was lucky.  The room that I put my studio into was on a
seperate line not 15' from the panel (this assumes that your incomming
line is clean and it may not be as I have suggested above).

The use of transient protection does make good sense.

If you have no choice and can't run a dedicated line or the house line
is dirty, then get a filter that is large and filters
common mode noise as well as differential noise.  The filter should be
sized to at least 3 times the maximum RMS load of the equipment in
use.

The simple filters in the plug strips will not be very effective.

>(through head phones--don't have monitors yet, will probably use home stereo  
>spkrs temporarily) listening to the headphone out of my mixers (Kawai MX8-SR  
>and Tascam 464) and I don't know how much is due to what; i.e. the mixers  
>themselves or the ligths (fluorescent) or RF etc.  Basically I want safe (for  
>the equipment), clean (quiet/"noiseless") power for my equipment (synths,  
>effects, mixers, mics, patch bay, amp).  BTW, I don't need the lights that the 
>PL-8/plus have (nor the line level LED's).  All wisdom is greatly appreciated.

Be aware that florescent as well as other noises that invade audio
equipment may not be line borne,  it could just as easilly be air
borne.

In troubleshooting problems tear the setup down to the mixer by
its self.  If that is as clean as it gets then start connecting
equipment until you find the problem.

Be prepaired to switch off lights, and other equipment in the general
vicinity to see if that's it.  Also be prepaired to switch off all of
the electrical circuits in the house, except for the studio, and
switch them on one at a time!  You may also be suprised as to just
what is also connected to the studio feed.

You actually may find it more useful to filter the offending
appliance.

I have a 5000 watt Sola line stabilizer/filter that could be for sale.
This is a huge (400+lb) unit that regulates line voltage and filters.

Not cheep!  Shipping would not be included!

-- 
Chris Christensen                  The opinions I express are my own,
chrisc@gold.gvg.tek.com            and sometimes they are wrong!
916-478-3419 FAX 916-478-3887      After all, I AM only human.