Any reason I can't use 14ga for transmission of line level signals???

[Tweak48]

I've got some pretty decent 14ga fine strand speaker cable under the carpet, and I'd like to use it now to run a signal from a preamp to a power amp, about 25 feet away.

Any reason why this wouldn't work??? We're talking 250 Ohms main output at 2 volts max, but I'm not sure what the interaction with the larger cable would be.

Thx.

[Mr. Widget]

Any reason why this wouldn't work???.If they are a twisted pair it should work, but if the conductors are parallel and flat you will likely pick up too much RFI and 60Hz hum... 25 feet is pushing it a bit for unbalanced anyway, but I have gotten away with it many times with proper coaxial cables.


Widget

[just4kinks]

It might be noisy - you'd be better off with a shielded cable. Maybe you can tie a signal cable to the end, and pull it through using the old wire.

[scott fitlin]

I've seen 75ft unbalanced runs, when a guy is in a pinch and has to do it to get functional, BUT, with preamps capable of outputting 10v or more.

The 14ga will get signal from point A to B, you might notice a loss of some high frequency. Running it under the carpet, you WILL hear noise through your speakers when someone walks over the cable, Triboelectric noise it's called. Tap your finger on an ordinary interconnect, or rub your fingers up and down the jacket of of some interconnects, with your system on, YOU will hear it amplified through your system.

You know what I would be hesitant about? Do u have children, or pets? Because two kitty cats playfighting, or children playing on the floor, hands and bare feet rubbing on carpets prodcuces static electricity! And if the static charge discharges in the "RIGHT" spot, you could hear a nice ZAP or POP through your system. Delicate tweeters may or may not favor this sudden energy burst, and depending on how powerful an amp your using, can do damage. If you don't have the availability of XLR outputs from your preamp, just use proper shielded unbalanced interconnects

What I would do, is go get some shielded 2 conductor + ground, 22AWG, and use that, West Penn, Belden, inexpensive, and decent wire. Wire +, -, and ground at the output of your preamp, run your cable under the carpet at the baseboard moulding of the floor/wall perimitter from preamp to power amp, use very fine tie wraps or self adhesive wire mounts, available at any electrical supply house, if you use tie wraps, there is a place on them to use a very small brad, or screw to attach them under the carpet to the floor/wall baseboard or moulding. Keeps the wires in place. And they are available in colors, so you can get what blends in invisibly and neatly.

About the carpet/static charge thing, don't laugh, IT CAN HAPPEN!

[Tweak48]

I've seen 75ft unbalanced runs, when a guy is in a pinch and has to do it to get functional, BUT, with preamps capable of outputting 10v or more.

The 14ga will get signal from point A to B, you might notice a loss of some high frequency. Running it under the carpet, you WILL hear noise through your speakers when someone walks over the cable, Triboelectric noise it's called. Tap your finger on an ordinary interconnect, or rub your fingers up and down the jacket of of some interconnects, with your system on, YOU will hear it amplified through your system.

About the carpet/static charge thing, don't laugh, IT CAN HAPPEN!

Thanks for the tips. The purpose of this drill was to get the power amp right by my speakers to reduce the signal loss. It's a total rework my my living room system where I used a biamped L-300 setup (which I recently sold). For now, I've left a single amp where it was, and run the speaker signal 20 feet or so. There is also a ground loop issue to deal with if I move the power amp by the speakers as all the source components and the preamp are on another house circuit. I think I could fix that, however.

I'll be posting photos of my new set-up shortly. I'm way happy with it, I can tell you that. 80 watt VTL power amp driving S-3100s.

[scott fitlin]

And I agree, amp close to speakers, short speaker wire runs has it's merits, and so does a balanced or pseudo balanced connection between pre and power units.

I find, depending on your gear, and listening tastes, that balanced interconnects give you beefier drive, but also a more solid sounding low end, and stronger, and well defined imaging too, in addition to lower noise characteristics.

[Ducatista47]

The purpose of this drill was to get the power amp right by my speakers to reduce the signal loss....There is also a ground loop issue to deal with if I move the power amp by the speakers as all the source components and the preamp are on another house circuit.

I'm no genius, but this makes very little sense to me. You want to run a tiny signal of a volt or two and almost no current twenty-five feet over concern with possible loss involving a powerful signal, over larger wire, over the same distance.

The amp to speaker run would incur frankly insignificant loss. Preamp to amp runs are more like source to preamp runs, fraught with danger from stray fields, transmission losses, loss of high frequency content, etc. All because of their weak (relative to a power amp output) nature. For these reasons balanced lines are sometimes used in home listening and sound reinforcement for preamp to amp, but not amp to speaker. The latter is unnecessary because such lines do not have noise problems; loss problems are minor and are dealt with solely with wire size and type.

In other words, small signal transmission is tricky and large is not.

Your concern seems backward to me, but as usual I am probably missing something. Another thing I avoid is having big electronics, like a power amp or a TV, close to big woofers. That is asking for unwanted interactions. Those powerful magnetic and electrostatic fields reach much further than tiny source and little preamp stuff.

Please forgive me if I am all wet,

Clark

[Tweak48]

I'm no genius, but this makes very little sense to me. You want to run a tiny signal of a volt or two and almost no current twenty-five feet over concern with possible loss involving a powerful signal, over larger wire, over the same distance.

The amp to speaker run would incur frankly insignificant loss. Preamp to amp runs are more like source to preamp runs, fraught with danger from stray fields, transmission losses, loss of high frequency content, etc.
Clark

I probably didn't do such a great job explaining my situation. I was trying to avoid having to re-install line-level cable under the carpets from the dining room to where the speakers are in the living room, when I allready have speaker cable under the carpet. The photo below (although I have placed the speakers differently in the room now) shows the situation. Notice the amplifier in the dining room. My main system (with all the source components) are just through the wall in back of the amplifier in another room.

This thread reminded me the sorts of interference that low level, unshielded signals can pick up.

http://i160.photobucket.com/albums/t181/tweak48/L300coffeeTable.jpg

[Mr. Widget]

I guess, give it a try and see if there is too much noise. If it is too noisy, one approach would be to run some Cat5e and a pair of balanced audio baluns. The Cat5e is small enough that it should pull through an existing speaker wire run.


Widget

[Ducatista47]

I probably didn't do such a great job explaining my situation.

You did a great job. My lack of skill reading what you wrote was the problem. Nice looking rooms.

Clark