New amp, new hum! Ack!

[Patrick Sun]

Okay, so I finally get my amp (Peavey CS800X) to power my Sunosub and got all the parts hooked up, and I get the dreaded subwoofer hum.

The hum appears to be from the cable TV connection to the VCR/TV, i.e., I disconnect the cable coax from the VCR/TV splitter and the hum goes away, connect it back, the hum returns.

So my questions are:

1. Should I try the cheater plug for the amp (converts a 3-prong plug into a 2-prong plug. I hesistate to do this, but if it's safe, I'll go for it.

2. I don't want to spend $100 for the Mondial unit that supposed to cut out the cable grounding problem. Should I request my cable company to come out and try to ground it "properly"?

3. Any other suggestions to get rid of the hum while keeping my cable TV connection connected all the time?




PatCave; HT Pix;Gear;DIY Projects;DVDs; LDs

[ThomasW]

Patrick

Try a "cheater" first. Don't get concerned about the "horror" stories. I've use these in my systems for decades without problems. If the problem continues, we'll explore other options.

1)Install a dedicated 8' copper rod just for the cable, if it's not already grounded that way. Grounding to a water pipe won't cut it. They don't go deep enough

2)Isolation transformers, sometimes they help sometimes they don't.

3)MAGIC block, these do work, I have used one for 5 years.




theAudioWorx
Klone-Audio

[Patrick Sun]

Thomas, okay, thanks for the reassurance. I'll pick one up after work today and hope for the best.

Another person suggested using two 300-to-75 ohm balun transformers to get rid of the CATV hum. Maybe I'll give both a shot and see which one works best for me (i.e. if the transformers work without degrading my CATV's video quality, I'll go with the transformers, if not, I'll use the cheater plug).




PatCave; HT Pix;Gear;DIY Projects;DVDs; LDs

[Bing Fung]

Thomas, what is a cheater plug?




Bing

[Patrick Sun]

Bing, it converts a standard 3-prong plug into a 2-prong plug and removes the roundish ground prong from being in use (disables some of the built-in protection that grounding provides). By getting rid of the ground prong, you can eliminate hum noise cause by improper match of ground planes in a house.




PatCave; HT Pix;Gear;DIY Projects;DVDs; LDs

[ThomasW]

Patrick

I've tried the back-to-back baluns they did nothing. The problems I experienced were a function of having 2 rooms that had shared cable and had some shared audio. This is a "recipe" for major ground loop problems.

But now the problem is solved, "cheaters" and the MAGIC block :B




theAudioWorx
Klone-Audio

[Patrick Sun]

Thomas, know anything about this Xantech #63400 (scoll down to the bottom of this link ). I'm still going with the cheapo cheater plug solution first.




PatCave; HT Pix;Gear;DIY Projects;DVDs; LDs

[ThomasW]

Patrick

It's a standard low buck isolation transformer.

http://www.jensen-transformers.com/vr1ff.html

These are the best of that type of device. Expensive $50. I tried one, and it didn't work for my needs. Jenson does offer a money back guarantee, and their products are some of the finest available in the world.




theAudioWorx
Klone-Audio