Ground Isolation, removing sibelance.


Hello all,

Is there some 'safe' way to isolate service grounds, or cable TV grounding apparatus to overcome the unbearable attributes they can induce into a system?

biteing the bullet and having Verizon FIOS completely installed just today I've noticed once agin the bug a boo of induced sibilance raising it's ugly head in my music system. I'm almost positive the FIOS is the culprit... albeit the 'grounding' of it. I did already disconnect the 'battery back up' for the phone service portion... yet today after the install was complete and after several hours the 'ground loop' induced sibilence was definitely apparent.

As an all underground fiber optic network, my first thought was to simply disconnect their ground wire from the service pole ground. I just don't feel too good about going in that direction... especially if I can 'isolate' it electrically somehow and maintain circuit integrity and safety.

Anyone know who, what, and where, to remedy this issue?

thank you very much.
blindjim
Mcfarland, thank you very much... I'll look for one of those gizmos if in fact I find the 'cable TV' the culprit, as I do highly suspect it to be... gotta disconnect it entirely first.

As the foremost symptom of ground loop issues is 'hum', or that offensive 60 cycle 'buzz' at the speakers, I'm not realizing that aspect. Simply sibilance. No hum or buzz. Fuzziness in the upper mid to treble ranges... most noticeable in female vocals and somewhat in the brass section, and then only from time to time... not constatly apparent. (if it is constant, I'm detecting it only at some frequencies then)

As much of my system is balanced though, not all, perhaps this is offsetting a good portion of the 60 cycle buzz, normally associated with ground loops.

I mainly suspect (if it's not the cable TV), it may be 'digital DC leakage' finding it's way back into the system. I'm gonna start the unplugging and flipping breakers today.

I did also run across the link below by doing a 'Google' search for "cable tv hum". The info provided therein is quite extensive and easily understood... with several possibilities outlined and a method for ascertaining just where the problem is or may be.

http://www.audioholics.com/techtips/setup/avhardware/groundloopcableTV.php

Probably not the last word on things but quite thorough and beneficial.

A quality iso transformer integrated in at either the service panel, or breaker box would be my prefference. As it covers a far wider approach... isolating the 'cable TV' ground, an additive measure of far less cost is also my pick. Between the two items things ought to shape up.

I'll follow up with my findings.
look at parts express they have a little black on for cable hum and its under 10.00 and works
In my experience, negative sibilance is always induced by dirty AC of which we are all victims to one bad degree or antoher. Certainly, common grounding to the neutral buss does not help matters, but I'm not aware that the actual grounding is directly responsible for negative induced sibilance.

You can certainly experiment by floating the ground on all of your equipment (at the wall outlets), have a listen, then try connecting the ground to your cdp only. This should give the best bang for the buck. Yes, there is awlays the safety concern, but so long as one component is grounded, the others will be too from the interconnects.

As for the negative sibilance, since everybody potentially has that problem, most likely you had that problem prior to your recent installation by Verizon, but perhaps not as bad.

The only remedy I am aware of to eliminate negative sibilance (not embedded in the recording itself) is via proper line conditioning. And proper line conditioning implies bi-directional filtering because the digital noise induced by your cdp (or a dac) is bi-directional and it will contaminate your other components. Even if the others are on their own dedicated lines, digital noise is known to make its way back to the service panel.

-IMO
stehno thanks

All the gear I run, except for the PC gear, is on dedicated ckts. I may have had some issue previous to the Verizon installation, yet it was not detectable. Regardless the volume. Even the main power for the monitor, tower, and a couple other peripherals are joined to a fair power strip engaged to another 'dedicated' ckt. trust me on this, dedicated strips, or dedicated ckts. do not, in and of themselves, prevent artifacts or noise from elsewhere in the electrical service from getting back to them... everthing is connected at the service panel/breaker box... it does however help. A lot.

I've a considerable number of DC transformers associated with the PC... sound card, monitor, tower, speakers, scanner, etc... and a few for the Verizon gear too. Ten or eleven at last count and I may have missed a couple... so I'm thinking they sure ain't helping things...

I'm wondering if anyone knows of a power bar, strip, etc.. that simply prevents DC from getting 'back' into the elec system? that's all it has to do... keep it from leaking back in... Probably have to get at least two unless there is one with about 12 outlets.
thanks a lot Bbaxley2

I got the part from Parts Express the other day and put it into the main cable feeding the house... things are far better now. That was of immense help. I didn't bother to pursue any other more expensive produtcs as the Parts Express item seems to have done the job. Thanks again, that noise/sibilance was killing me. the boxes Verizon supplied were also 'brandy' new and they needed to run in as well, so they were contributory factors too.

Now I've got to find out about what sort of strip/bar, ??? I can get to plug in a bunch of low voltage devices that will prevent anything they produce from getting back into the house' power supply.

I'd as soon not 'condition' my main devices if at all possible.. because conditioners change the sound.... just attend to those little transformered low voltage items instead. sort of something that acts like a 'one way' gate and traps/filters out any DC or harmonic interferences from finding their way past it and into the system. Something inexpensive... or at least less than a bunch.

Got any further ideas, or does anyone else?
i would guess a wire world power strip about 40.00 would be the best,as long as you put a good power cord on it.parts exspess does sale some furman strips that has worked for me check them out

Thanks, Bbaxley2. Will do. I think however instead of quieting things with a $40 - $50 strip + a $200 cord... I'll try to get a iso transformer or filltered strip... but it is most appreciated.

...and as I've been experiencing some intermittent outages recently with the FIOS optical media services Verizon is due to replace the main outside unit and router tomorrow AM... perhaps all along that's the bug. We'll see. Sure hope so.