On 11/02/03 04:29, Stew Pidasso said...
Doesn't anyone use stereo line-level cable? I
use it all of the time. It consists of two twisted
pairs, each individually shielded, with a separate
ground wire. I can usually run line level over
a hundred feet with minimal interference.
I chose the CAT5 approach for a couple of reasons --
the adaptors are isolation transformers, so ground loops are unlikely to be a problem; if he can get away with not spending the money on the transformers, so much the better;
|Solder the shield or
drain wire to one of the other wires that are
used for ground.
For best noise rejection, i.e. if you are going to bother AT ALL with two conductor shielded, the ground should be connected at the source end. Since he wants to be able to plug the source in at different locations, there is no constant "source end."
If interference is a problem, use a balanced line
sender and receiver pair.
The CAT5 - audio device is a balanced to unbalanced adaptor. (Bal to Un = balun). Passive ones are available, probablt at lower cost than the active ones you recommend.
You will get virtually no hum
even under poor conditions.
I got no hum when I used the adaptors, and I have also had success just using CAT5.
If you use these
devices, you would need a second balanced line
receiver for the third location. One sender will
take care of both receivers.
Weren't there three places he wanted to have amps, where he could plug his player in at each one? So either he plugs into the balanced line somehow, or he has three senders and three receivers, all in parallel...will this load the line and, for instance, kill the highs?
If you don't convert to balanced line, you will
need a distribution amplifier to feed two receivers.
A distribution amp assumes you have one source location and other receiving locations. Look at his email again -- his approach would need a distribution amp for each location, a run from each location to the other two, and switching to be able to select...and he would have to flip switches at all three units to have them all work.
If any of
the three receivers is not on, it will likely
cause distortion in the ones that are being used.
If all three are on at the same time, the distortion
will not be obvious.
The distortion is caused by chips or transistors
in the unpowered receivers acting like diodes
shorted to ground when they are not powered.
It is more obvious with CD or signals with more
amplitude.
Absolutely true and technically worth knowing. I have only found this to be a problem with amps and receivers that are at least ten years old, though. But in a parallel setup, I DID get an AM radio station through a five-year old powered-down Yamaha RX-V870 the other day!
Did you notice that almost all distribution devices
are for audio and video? You might want to take
advantage of the video distribution feature.
Even the CAT5 ones. In fact, they started as video products, then added one channel of audio, then two.