Line filtering to improve stereo sound

Archived from groups: rec.audio.tech (More info?)

>Would something like this tripp-lite improve the sound of my stereo or
>is one of those more expencive boutique units needed?

Do you have reason to believe that your stereo's sound is being
adversely affected by power-line noise? Any pops, clicks, buzzes,
intermittent hisses, and so forth? If not, you may very well not have
any problem that a powerline filtering system could address.

Isolation trannies can be beneficial in some cases, but in most
situations they're probably overkill. A simple Corcom (or similar)
EMI filter module can greatly attenuate most RF noise on the power
line.

There are other RF problems (and they aren't all that rare) which
neither a simple EMI filter, nor an isolation transformer can help
with. One of the commonest ways for RF noise to get into a stereo
system is through the speaker cables - the cables act as an antenna,
the RF gets back into the power-amplifier output stage and is
rectified by one of the diodes or transistors and becomes audible.
Local CB or ham radio transmissions can be picked up in this fashion.
The usual cure for this is a couple of ferrite cores, through which
the speaker cables are wound a few times - usual cost-to-fix is under
$10. The same fix (ferrite cores or clamp-on suppressors) can help
with RFI infiltration through the audio interconnection cables.

> http://www.tripplite.com/products/ [...] ductID=226

This product has a 2.1-ampere limit. If your stereo draws more
current than this (and it's quite possible if your receiver or amp
delivers more than perhaps 50-70 watts of total output power) then
you'd be overloading the transformer. You might trip its breaker, or
start suffering voltage sag at the receiver which could cause sonic
problems rather worse than the transformer was intended to cure.

--
Dave Platt <dplatt@radagast.org> AE6EO
Hosting the Jade Warrior home page: http://www.radagast.org/jade-warrior
I do _not_ wish to receive unsolicited commercial email, and I will
boycott any company which has the gall to send me such ads!

Archived from groups: rec.audio.tech (More info?)

> Would something like this tripp-lite improve the sound of my stereo <

No. A good power filter will remove obvious clicks and pops, but the notion
that it will make a subtle (or not so subtle) improvement in sound quality
generally is just a sales pitch. If you don't hear clicks and pops, you
don't need a power filter.

--Ethan

Archived from groups: rec.audio.tech (More info?)

In <_yoSd.10142$M4.6120@fe08.lga>, on 02/21/05
at 11:57 AM, Terrified <crantz7z@windsurf.net> said:



>Would something like this tripp-lite improve the sound of my stereo or
> is one of those more expencive boutique units needed?

>http://www.tripplite.com/products/product.cfm?productID=226

If you have a decently designed audio system, nothing is needed -- it
is mostly "the emperor's new clothes".

That said, there can be special situations. For example, certain areas
near me are prone to lightning damage and special precautions should be
taken for any type of electronics installed in those homes. In that
area, I like to use industrial duty whole house surge suppression and
"line conditioners" (these units contain transformers, are rather heavy
for their dimensions, and are a step above simple surge suppression.)

Other areas are flooded by nearby high powered radio and TV stations.
In my area most of the TV and FM stations are clustered in on 1/4 mile
area. Power line filtering is helpful, but good wiring practices (keep
everything short, use good shielding) are even more important. In
really bad areas connecting 40 or so feet of wire to a speaker is
enough to convert it into a "radio".

If you have obvious room light flickering, audible pops (usually
associated with particular lights and/or appliances), power line
filters *MAY* improve your audio quality, but there are larger issues
that should be addressed by a professional. Some of the issues have
safety overtones. If you own your home, fix the fundamental problems.
If you rent, talk to the landlord and consider moving on when the lease
is up if the problems are not resolved.

Those sub $10.00 "surge protected" outlet strips are worthless for any
kind of protection, but they sometimes are decent outlet strips.

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