passing audio through unused telephone connection

[nige838]

I'm interested in using the unused telephone hookups in my small apartment to send line level inputs to different rooms. My understanding is that theres 2 wires for power and 2 wires for signal. If there's no service going to the line, couldn't I feed low level audio through the signal lines to seperate amplifiers in different rooms?

Thanks for any feedback

[sofaspud]

There are 2 wires (red/green) or 4 wires (+black/yellow). Power and signal share a pair so there may well be just 2 wires. The most important thing is to be absolutely 100% certain nothing remains connected to the telephone network. Then you could use this for distribution, but how effective the end result I could only guess. Using a line driver is probably a good idea.

[sreten]

Hi,

No. The two wire incoming line provides power and AC connections.
In the UK : UK Telephone Wiring

Your main issue would be lack of shielding, hum, followed by some noise.
You don't even have twisted pairs to help, like the incoming pair line.

I'm not saying it can't be done, but I've never done it, don't think it will work.

But between two extension points not linked to a master socket you could
try connecting the 4 wires as L-, L+, R+, R-, it just might work, or then not.
I think it won't work well, but that does depend on low driving impedances.
(i.e. it would be easier to use them for extension speakers than line level.)

rgds, sreten. (ex telecoms amongst other things)

You would need to disconnect the wires from the master to the first extension ....

[VictoriaGuy]

Originally Posted by sofaspud

The most important thing is to be absolutely 100% certain nothing remains connected to the telephone network.

You'd probably need access to the building telephone room/cabinet to be sure of this. Much easier to check in a house.

[VictoriaGuy]

Originally Posted by sreten

Your main issue would be lack of shielding, hum, followed by some noise.
You don't even have twisted pairs to help, like the incoming pair line.

It depends on the age of the building, to some extent. Here (in Canada), Cat5 is standard for phone wiring in new building or renovations. It's difficult to find 'old-style' phone cable (4-conductor) in most places like HomeDepot.
I learned this a couple of months ago when running new phone wiring in a house- it was a surprise to me.

[sreten]

Originally Posted by VictoriaGuy

It depends on the age of the building, to some extent. Here (in Canada), Cat5 is standard for phone wiring in new building or renovations. It's difficult to find 'old-style' phone cable (4-conductor) in most places like HomeDepot.
I learned this a couple of months ago when running new phone wiring in a house- it was a surprise to me.

Hi,

That is not surprising as the twisted pairs are still fine for telephony,
but the wiring is much more suitable for computer LAN's and the like.

Though wireless hubs are taking that over.

rgds, sreten.

[nige838]

I live in the US and my understanding was that there was a low voltage DC (+/-) and then a input and output. If none of these are in use and the run is less than 30', I don't think that these concerns are substantial. I'm going to give it a try sometime this week and post back

Thanks

[Pano]

The is about 90-100 VAC on the line when the phone rings. Just be sure you don't get that into your audio system!

[godfrey]

Or into yourself! I got zapped once by that.

[sofaspud]

I live in the US and my understanding was that there was a low voltage DC (+/-) and then a input and output

Just 2 wires in the US. ~48VDC on-hook. There is no input and output; it's full duplex on the single pair. Disconnected from the network, there's no harm trying your idea.