 
|
Audio Asylum Thread Printer Get a view of an entire thread on one page |
For Sale Ads |
|
|
Audio Asylum Thread Printer Get a view of an entire thread on one page |
For Sale Ads |
69.201.171.40
Hi all - I am a complete and utter DIY noob, and I just finished up my first ever project - a set of speaker cables. Each side (L/R) is comprised of 6 individual 22AWG silver wire (about 3 feet each), with 3 sets of twisted pairs, and then with the 3 twisted pairs braided together (so 12 wires in total for the stereo setup).
They are unterminated for now - running the bare wire into my amps/speakers. I tested for continuity with no issues. They have a nice sound, but there is a "scratchy" sound present most (but not all) of the time, particularly on one side. It happens that on that side, the cable runs near a computer, my pre-amp's power supply, and into its respective monoblock amp. The other speaker has a little bit of this scratch, but not as much - that one sits near a PS3, and its respective monoblock.
I tried swapping the cables around, and find that the scratch remains noticeable on the same side. I checked my tubes and everything, and then tried a separate set of cables, and find no scratchiness on either set with the alternate set of cables (Stratghtwire Rhapsody S - but much longer at about 8 feet each side - and I believe shielded).
So, it looks like I have some sort of interference (and/or just horribly constructed cables).
Any advice for a noob here? I plan on trying another set of cables shortly, using 16 AWG silver wire, but would like to follow a better plan, if possible.
Thanks in advance!
Justin
Follow Ups:
Your twisted pair cables have higher capaciance than other cable geometries. It just may be high enough to make your amp oscillate, hence the sound.
Here's an Asylum Search on the topic.
Bill's Audio Cave
Thank you very much, Batman - I'll take a look. I'm going to do another set in a week or so - perhaps this will give me some ideas to try.
Cheers!
Give the cables time to settle. You may be experiencing break-in syndrome. However, if it is on one side it may be instability of the circuitry on one side or the foresaid interference. Interference is the lesser of the evils.
Cut off the computer etc and see if the scratchiness goes away.
Another possibility is a rubbing voice coil in the speaker. Try swapping speakers.
With the amp off and the cables connected to the amp; test the resistance on each side of the speaker cable. This will help to isolate the problem to the amp.
Do the above with the cables only connected to the speakers. Variance will let you know if there is a problem in the speakers.
Make sure the connections are tight. If the amp uses spring clips for connections you may hear scratchiness.
DaveT
I'm not sure about scratchiness, but most cables need some break-in time. When I've heard cables settle in, the treble tends to loose its prominence and the soundstage fills out. If you want to try to absorb some RFI and see if the sound improves, you could try ERS cloth or mu metal. The Tweak Geek has ERS paper:
http://www.tweekgeek.com/_e/Stillpoints_ERS_More/product/ERS/Stillpoints_ERS_RFI_Killer_Just_lay_on_top_of_your_DAC_CD_player_or_power_conditioner_.htm
and the EMF Safety SuperStore (I kid you not) has all sorts of EMF shield materials:
http://www.lessemf.com/magnetic_shielding.html
As a test do you have another set of cables you know are good? Why not try them and see if the problem is still there? Process of elimination is what troubleshooting is about.
Hi Uncle Mike - yep, I did try swapping in another set of "known good" cables (I mentioned that above), and the scratchy sound is not present.
Did you try to reroute your new cables to see if the interference you mention changes? If it does then I think you know where this is going. Shielding or rearranging your equipment if you want to keep those cables. DIY is a journey and you learn along the way!
Yep - i did switch the new cables around and the scratch was still prominent on the same side. So, yeah - might have to think about how my equipment is arranged, or look at shielding somehow.
With that construction I would think they would be pretty good at noise rejection. As a test you might try wrapping them in Aluminum foil to see if the problem goes away. The foil creates it's own problems so I wouldn't recommend leaving it.
Another thing to try is a bare wire (a thin gage will work fine) woven into your cable, tied ....AT ONE END ONLY... to earth ground. The screw holding the faceplate to the wall outlet should be grounded so use a crimp lug to get under it.
Edits: 01/08/11
Thanks for everyone's help. Just wanted to post an update.
I made a second set of cables, using fewer strands (2 per cable, so 4 in total) with lower gauge and larger diameter tubing - worried that the prior set had too much twisting and braiding going on.
I attached these, and the static was still there, but less so.
I started moving things around (components, wires, etc), turning things off, etc. I noticed that when the computer was swithed off, the sound went away. So, I do not think this is an oscillation issue.
Anyway, after considerable poking around, I managed to isolate the source of the noise to a power line Ethernet adapter that was connected to the computer (and to a nearby wall outlet). When I unplugged it, and switched to Wifi - the static went away.
I need a network connection as I store my music on an external NAS in another room. So, I ended up purchasing a (rather long) Ethernet cable and ran a hard wire to my router - and the static sound has gone away.
The cables sound great!
Cheers to everyone who chimed in,
J
No cats, but several gerbils... ;)
Yep, I did search and read several topics, many of which mention hum rather than scratchiness.
Read up on how to deal with it with various filters here on Tweaks. Use the search function.
Doesn't really sound much at all like an RFI problem. I say blame it on the Stones.
Do you own a cat by any chance?
Post a Followup:
| FAQ |
Post a Message! |
Forgot Password? |
|
||||||||||||||
|
||||||||||||||
This post is made possible by the generous support of people like you and our sponsors:
Top of Page ]
[ Contact Us ]
[ Support/Wish List ]
[ Copyright © 2025, Audio Asylum, all rights reserved ]
