gto6 Posted February 28, 2001 Share Posted February 28, 2001 I have a pair of mcintosh 30 watt mono blocks on top of a pair of khorns. The preamp is about 25 feet across the room. I made an interconnect out of Belden 4 conductor 18 gage shielded wire and monster cable RCA jax. The wires work fine when the amps are on top of the preamp, but, when run across the room, above my drop ceiling, past a recessed light fixture and above a flourecent light, I get a nasty buzz coming out of the khorns when I turn the lights on using there dimmer switches. I don't think a power condition will help because I ran extension cords to an outlet with nothing on it, its a dedicated line I use to weld. Could there be a problem with the type of cable I selected, or would I have had the problem with a commecially boughten interconnect. Any thoughts are greatly appreciated. I just bought 7 ft of Audioquest speaker cable I can't wait to try out. Quote Link to comment Share on other sites More sharing options...
Ray Garrison Posted March 1, 2001 Share Posted March 1, 2001 Maybe one of the engineers here can recommend a specific cable that is sufficiently shielded to help out here; I certainly can't. I would point out that you've created what is in all likelyhood the most hostile environment possible to route your cables through. 25 feet of line level signal (tough) going past a flourecent light (even worse) that has a dimmer on it (most worser) into tube amps (getting worser still) driving one of the world's most sensitive loudspeakers ( I surrender) - if you can find a product that shields against humm in this configuration, please post it. I want some. Ray ------------------ Music is art Audio is engineering Quote Link to comment Share on other sites More sharing options...
gto6 Posted March 1, 2001 Author Share Posted March 1, 2001 I was thinking of running the interlinks through a metallic electrical conduit, would that provide a better shield, or would I worsen my already miserable situation.......or maybe reroute the interlinks, for that I'd have to add length. Quote Link to comment Share on other sites More sharing options...
Flason Posted March 1, 2001 Share Posted March 1, 2001 Ditch the flourecent light and the buzz will go away. Experiment by turning it off and on while your amp is going to confirm. Unless you by some heavily shielded conduit, no amount of shielded speaker cable will work. Quote Link to comment Share on other sites More sharing options...
Derek Posted March 1, 2001 Share Posted March 1, 2001 Try disconnecting the shield on one end of the cable. This often cures problems. Derek Quote Link to comment Share on other sites More sharing options...
Mighty Favog Posted March 3, 2001 Share Posted March 3, 2001 Because of one dimmer switch in my home office I always get a nasty buzz type interference throughout the entire house on any radio tuned to an AM station. Doesn't matter if the dimmer is all the way up or somewhere in between. ------------------ Tom KLF-20 Mahogany Carver Receiver MXR-150 Yamaha PF-800 Turntable/ Sure V15 Type V Cartridge Carver TL-3100 CD Yamaha K-1020 Cassette dbx 1231 EQ dbx 3bx Series Two H.H. Scott 830z Analyzer Monster Interlink 300 mk II Original Monster Cable Quote Link to comment Share on other sites More sharing options...
WMcD Posted March 4, 2001 Share Posted March 4, 2001 This is a very long run for a high impedance connection. My guess is that even if you solve the noise problem, you're going to have a problem with decrease in high frequencies. If you absolutely want to make a run like this, you might try using tranformers on either end. These transform the high impedance line level output of the preamp to 600 ohms for the long wire run, and then back up to high impedance on the amp end. It seems to me that the XLR microphone transformers sold at Radio Shack will work for this. On the other hand, this is going to take some soldering. I've not use this myself, but it would be the place I'd start. If you need more info, I'll be pleased to answer any questions. Regards, Gil 1 Quote Link to comment Share on other sites More sharing options...
gto6 Posted March 12, 2001 Author Share Posted March 12, 2001 I fixed the problem without removing any of the fixtures. I bought a 35 foot set of Tributary double shielded interconnects, being careful where the cables were run. I have a line conditioner/surge protector on the way, it sure won't hurt anything! Happy Tunes! Quote Link to comment Share on other sites More sharing options...
Guest BobG Posted March 12, 2001 Share Posted March 12, 2001 For what it's worth, running the cable in conduit would not have helped. The conduit would merely reradiate the noise into the wires inside. Quote Link to comment Share on other sites More sharing options...
gto6 Posted March 12, 2001 Author Share Posted March 12, 2001 Yep, thanx bob...I did some research and found that wouldn't work, I found an industrial communications company in Illinois that makes sheilded conduit in 3/4" I.D.......it costs $8.08 per foot. I would have to buy $325.00.......not an option. Its fixed and my Khorns and McIntosh tubes sound AWSOME! Quote Link to comment Share on other sites More sharing options...
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