worst digital offender?
Oct 15, 2002 at 11:59 AM Thread Starter Post #1 of 11

KShaft

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When I turn off my computer and my cable modem, my rig gets a hell of alot less grainy and looses a thinness in vocals that is very annoying even in my r10s.

I think the cable modem is the true offender.
Any one else have similar situations?

kind of a tweak when I shut off the offenders!
just curious...
k.s.
 
Oct 15, 2002 at 2:20 PM Post #3 of 11
Make sure that your rig is not plugged into the same circuit (on the same circuit breaker) as your computer. It also sounds like a good power conditioner is in your future.
 
Oct 17, 2002 at 8:56 AM Post #4 of 11
Well I have thought of power conditioners, however I am also wary of current limiting and I would like to avoid that. Also I was thinking of aquiring a shyunata pc for my cdp and I am aware that they recomend pluging it straight into the wall. If I get say a ps 300, for a conditioner/regenerator, then i will have to get another power cord as Shyunata products dont mesh well with ps audio products.

Oh I installed a wattgate outlet and after shutting down half the house im SURE its not on the same circuit!
biggrin.gif


Thanks for the advice, what power conditioners were you thinking of??

k.s.
 
Oct 17, 2002 at 11:37 AM Post #5 of 11
Quote:

Originally posted by KShaft
When I turn off my computer and my cable modem, my rig gets a hell of alot less grainy and looses a thinness in vocals that is very annoying even in my r10s.

I think the cable modem is the true offender.
Any one else have similar situations?

kind of a tweak when I shut off the offenders!
just curious...
k.s.


You are correct! Computers inject a lot of noise into the AC Lines. Lots of other things do too!
If you want to try something interesting call "The Cable Company" (1-800-FAT-WYRE) and borrow an Audio Prism Noise Sniffer and a pack of Quiet Line Filters.

Quiet Lines
Noise Sniffer

You will be surprised at how noisy things are, as well as how effective the Quiet Line filters are.
TR
 
Oct 17, 2002 at 9:15 PM Post #6 of 11
You might consider using transformer isolation between your computer and the rig.Not cheap but very effective with rf garbage

check out the Jensen transformer site

Rickster
 
Oct 18, 2002 at 3:27 PM Post #7 of 11
thanks again all.

ill look into that stuff when i get my head above water...
heheh
thanks,
k.s.
 
Oct 18, 2002 at 3:49 PM Post #8 of 11
just an add in ***************

Transformer isolation is a solution for any source that produces ultrasonic artifacts (breaks ground loops too !)

Computers,VCRs,CD players,DVD,digital cable boxes,satellite receiver.

You don't want gain so what you are looking for is a 1:1 gain ratio.
Impedence matching is also very important.
10K ohm in/150 to 600 ohm output would be ideal.

The cost of the Jensens is not cheap (nor the Luhndals,others) so you may want to check into Edcor transformers.yhey are reasonably priced and they also do custom work.

The old "you get what you pay for" holds true but at $100 per channel I personally would only use the best with the best .

Not that I am implying your computer sucks but the resolution of the upper end transformers maybe overkill in the application

Another point-you can enhance the RF filtering with transformer bypassing with capacitors , check out the very extensive pdf library at jensen for details

Rick
 
Oct 18, 2002 at 5:00 PM Post #9 of 11
Have you tried plugging your computer and cable modem into a regenerative UPS? That should isolate them from the power circuitry, and let you plug your stuff into the wall.

(regenerative means it converts 120VAC from the wall into 12VDC to charge the battery, then into 120VAC again to power your computer. I believe many computer UPS-en are made this way - probably not the cheap ones though, and I'm not sure how to identify one unless it says regenerative on the package...)
 
Oct 18, 2002 at 5:59 PM Post #10 of 11
apples and oranges.

More than one culprit when it comes to induced noise and the means to rectify it

AC line induced-plenty of products out there , mostly the info is here.
But for me at least there are times when a line filter SCREWS UP the sound.
Sorta beats down the dynamics and present an overall uninvolving boring sound so I only filter the line at video and digital sources.The amps and line level stuff is "out there" naked.

RF signal induced.More of a problem in a high gain situation such as with phono or mic preamps than with the average componant.But still it never hurts to have some RF caps at the inputs and shielded cables (something I rarely use and never have a problem but I have all short runs)

ultrasonic digital artifacts-lotta stray crap floating around in computers , VCRs ,televisions, etc.
Look at the back panels and youwill see FCC compliance codes !
Damn transmitters !
And do not for a moment think the FCC gives a rats ass about audio quality in the home , they do not.
They are only worried about a signal radiating strong enough as to interfere with other devices in the home or even outside the home ,such as the neighbors TV picking up your microwave.

Audio equipment on the whole is pretty well designed in these times but the final frontiere for good sound is putting your system in a "bubble" .

That is isolated itfrom ALL things not related directkly to the sound of the actual componant.
And that includes electrical as well as mechanical interference.

Isn't this fun ?

evil_smiley.gif
 

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