homemade power conditioner?

[Scott Dorsey]

In article <da316040.0404122051.1dbfab95@posting.google.com>,
Bob Chandler <bassface@pacbell.net> wrote:

kludge@panix.com (Scott Dorsey) wrote in message news:<c5e6ji$m41$1@panix2.panix.com>...
Bob Chandler <bassface@pacbell.net> wrote:
No, it's not a standby unit. I made sure of that before I bought it.
Also, no hum or problems from running the furman bal power from the
UPS either. Yes---my studio is finally QUIET again.

Wait, you had a Furman balanced power box in the line and that didn't
help anything, but an online UPS does?

Curiouser and curiouser.

Yes. the Furman did very little. The UPS eliminated essentially all
the noise I was getting. Some FX units that I just assumed had a high
noise floor became much quieter too.

I agree with the others that I think your UPS is really a standby unit.

But before doing anything else, you need to get a line analyzer or at least
a scope on your power line. See what is really on there and see if you can
figure out how it got there. It may be something the power company is
required to fix.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."

 

[Scott Dorsey]

Bob Chandler <bassface@pacbell.net> wrote:

I know it's not running off the batteries unless the power's down.

That is the definition of a standby UPS as opposed to an online one.

I said it has a sine wave output---is that not possible??

That's only important when it's running off inverter, and most of the
time it's not running off inverter. So the benefit you are getting has
nothing to do with the quality of the waveform from the inverter, it has
to do with the line filtering on the front end.

This pretty much guarantees that your problem is due to RF noise on the
power line. But what kind? And how did it get there? It isn't really
essential to know since you have a good workaround, but it would still
make me curious.
--scott

--
"C'est un Nagra. C'est suisse, et tres, tres precis."

 

[Z]

In article <c5h3ek$pvt$1@panix2.panix.com>, Scott Dorsey
<kludge@panix.com> writes

In article <da316040.0404122051.1dbfab95@posting.google.com>,
Bob Chandler <bassface@pacbell.net> wrote:
kludge@panix.com (Scott Dorsey) wrote in message
news:<c5e6ji$m41$1@panix2.panix.com>...
Bob Chandler <bassface@pacbell.net> wrote:
No, it's not a standby unit. I made sure of that before I bought it.
Also, no hum or problems from running the furman bal power from the
UPS either. Yes---my studio is finally QUIET again.

Wait, you had a Furman balanced power box in the line and that didn't
help anything, but an online UPS does?

Curiouser and curiouser.

Yes. the Furman did very little. The UPS eliminated essentially all
the noise I was getting. Some FX units that I just assumed had a high
noise floor became much quieter too.

I agree with the others that I think your UPS is really a standby unit.

But before doing anything else, you need to get a line analyzer or at least
a scope on your power line. See what is really on there and see if you can
figure out how it got there. It may be something the power company is
required to fix.
--scott

If consistent noise is an issue you may need to beef up your earthing.
Items with switch mode power supplies eg IT equipment, battery chargers
have high protective conductor currents. Fluorescent lighting also puts
gumph back on the mains.
/this current becomes evident as a voltage (i.e. noise floor) which
varies inversely as conductor resistance so low resistance earths help
reduce the noise.

For high quality audio such as studio gear one would generally be
thinking of a dedicated circuit from the consumer unit maybe even a
separate consumer unit.

I ran 10mm sq earths from the amp and t/table sockets to the main
earthing terminal for my hi-fi. Now clean as a whistle. I'm wiring a new
radial (branch cct in USA) circuit for hi-fi in Pirelli once the
harmonised colour cable is in stock at wholesalers.

Try these PQ links:
http://www.copper.org/applications/electrical/pq/homepage.html
http://www.marcspages.co.uk/pq/index.htm
http://www.lpqi.org/lwslib/ktwse?welcome need to register
--
Z
Remove all Zeds in e-mail address to reply.

 

[Frank C]

What about these? They seem pretty inexpensive.

http://www.equitech.com/products/seconds/seconds.html

Scott Dorsey wrote:

Bob Chandler <bassface@pacbell.net> wrote:

I was looking into sine wave generators like the ones that come on the
more expensive UPS units and output sine wave all the time -not just
when running off the batteries. Some research showed the that sine
waves are dirty but apparently the more expensive units are high
quality. I bought an APC Smart 2200UPS and all my power/noise problems
went away. I've been able to run my Trident board, a rack of pres and
FX well as my computer workstation all off of this unit. The
improvement in background noise is staggering. I have started to plug
the Furman into the UPS--is there any reason why a balanced power
suppy should not be used with a UPS that outputs sine wave??


If that's what I think that is, it's a standby UPS, so the inverter
isn't actually running when the power is on. If this is the case,
then the benefit you are hearing is because the unit has a line filter
built into it, and you're just hearing the effects of the low-pass
filter removing all the line trash.

In general, this seems like a really expensive way to get line filtering,
but since you should probably have a UPS on your DAW anyway, it sounds
like a good way to go.
--scott

 

[David Williams]

This is an old thread now, but I just read it. I didn't see anyone (though
they might
have) mention a motor-generator. Sure, it can be expensive and wasteful, but
you
can build one yourself, and with a massive flywheel, not much high frequency
or impulse noise will get through. You can drive it with a variety of
standby devices
when the normal feed is down.

Any inverter you could afford puts out an MFM (modified square wave)
output.
This is an enormous source of noise, much more than on a power line.

Synthesized sine wave inverters have become much more affordable lately, not
that they will be "good enough," but they're definitely not "modified square
wave."
What's more, there's quite a bit of used equipment around now, as many home
power gurus end up buying larger inverters and selling the smaller ones.

David