What cable to use for audio (phono) diy connections?

[James]

I want to get unamplified sound between my computer & DAB radio (in the kitchen) and my amplifier (in the sitting room). The cable route is about 10-15m and goes through the cellar, so it would be nice to have a socket there as well.

I have bought a couple of double phono sockets from nexxia

and linked them up with telephone wire (which was what I had to hand). Not good. There's a hum, and although reasonably loud music is worth listening to, speech is very distorted.

Now I'm sure there are many things I have done wrong: using telephone wire; maybe using solder (though the sockets have solder tags); I should also mention that the cables connect through a telephone junction box. But I can't find any cable anywhere specified for this purpose (as opposed to speaker cable). What should I use (looking for something cheap, that I can buy by the metre, or in a 10 or 25m reel, either over the net or on the UK high street)? Also advice about a junction box if that's likely to make a difference.

Many thanks in advance,

James

[Harry Bloomfield]

James wrote on Sunday (01/02/2004) :

You will need to use screened audio type cable for this, with the screen connected to the outer of the plugs, two cable runs for stereo. You might be lucky and be able to get hold of some figure of 8 type stereo cable.

[Lurch]

Try

and look for part no. N08AP.

SJW A.C.S. Ltd.

[Richard Savage]

In my experience the quality of the interconnections has almost as much effect on the finished sound as does the quality of the speakers. I strongly suggest that you avoid at all cost anything cheap to link these devices.

Do I understand that you are feeding the audio o/p from PC and DAB unit to your amp? Then spend LOTS of money on the cables and connectors (consider gold plated - they're not that dear) and do solder the cables. I expect you'll only want to do this only once!

Unfortunately I can't remember the best practice for audio cable screen connections to avoid earth loops - is it only connect the screen at one of the devices? Doubtless someone else will advise.

Oh and it's

(no 'S')

What's the story with the telephone junction box?

BOL Richard

[Alan Deane]

Connect the screen at both ends, use a reasonably heavy twin screened figure-of-eight able, preferabley the "oxygen free copper" stuff. As Richard has already said, don't try to do the cabling too cheap - you'll end up doing it twice.

Alan.

[geoff]

In message , Richard Savage writes

Or rather google CPC - quite a bit cheaper normally

[Dave Plowman]

Places like Maplin sell audio co-ax designed for this purpose by the meter or drum - the same stuff as a phono lead is made of. However, when connecting two or more separate systems together, there's a possibility of an earth loop which will cause hum if they are all earthed through the mains plug, as your computer almost certainly is.

But the wrong cable shouldn't make the sound distorted - it's only likely to add hum. It could be that connecting the inputs of the computer and Hi-Fi together is via long lengths of wire is causing some instability - just a guess. Is it distorted on both, if you connect them individually?

The 'correct' way to do this job is with a distribution amplifier - same idea as you use with a TV aerial - but I'm not sure if domestic types are available at a reasonable price, they're more a pro thing at pro prices.

Unbalanced circuits - this is what you have - can work well over reasonable distances. I've got my STB in the front room fed to the kitchen TV via a SCART lead over 15 metres long, and it works well.

[Lurch]

I was going to point this out but going on the basis the OP seemed quite happy with 'reasonably loud music' on telephone cable, I took it he wasn't an audiophile as he would already know about quality OFC, gold plated etc interconnects if he was. And, quality aint cheap, but cheap was mentioned in the OP.

Ooops, I'll try again then.

look this time for part no. XS39N. _Better quality!_

SJW A.C.S. Ltd.

[Owain]

"James" wrote | I want to get unamplified sound between my computer & DAB radio (in | the kitchen) and my amplifier (in the sitting room). The cable route | is about 10-15m and goes through the cellar, so it would be nice to | have a socket there as well. | I have bought a couple of double phono sockets from nexxia |

and linked them up with telephone wire | (which was what I had to hand). Not good. There's a hum, and | although reasonably loud music is worth listening to, speech is very | distorted. | Now I'm sure there are many things I have done wrong: using telephone | wire; maybe using solder (though the sockets have solder tags); I | should also mention that the cables connect through a telephone | junction box.

Hopefully one not used for telephone lines!

Actually, you can shove line-level audio down phone cable quite well provided that it's twisted-pair and you get the pairs right. You may also have some 'dry joints', so practice your soldering. Hum is usually caused by poor earthing and screening; distortion may be a sign of a bad joint.

| But I can't find any cable anywhere specified for this | purpose (as opposed to speaker cable). What should I use (looking | for something cheap, that I can buy by the metre, or in a 10 or 25m | reel, either over the net or on the UK high street)? Also advice | about a junction box if that's likely to make a difference.

Maplin order code XR21X at 49p/m or XS94C at 59p/m are figure-8 screened audio cable suitable for making audio leads. Per metre or 100m reel. (Those are last years prices, check in shops or

) If you want to join two phono leads end-end QT64U is a stereo phono-phono coupler. It's not audiophile stuff but you're only using it for DAB :-)

Maplin XS39N at £3.49/m is rather heftier but will need heftier plugs too.

Owain

[Lurch]

If you happen to have an account with them that is.

SJW A.C.S. Ltd.

[geoff]

In message , Lurch writes

Although I do, I never thought it was a pre-requisite for ordering from them. I'm sure that you do for the other link - Farnell (CPC's now parent company)

[Ray]

rs components, possibly -

367-561 25m £9.306

[Dave Plowman]

You're a bit lacking in experience, then.

[Dave Plowman]

You can with video as well. ;-)

Ordinary telephone pair was used for distributing the signal to radio transmitters for years before digital came along, and a carefully equalised line was capable of giving excellent results over many, many miles.

I use telephone cable in my place to distribute audio - I've got 10 circuits in one cable, non of them screened, and the results are excellent. But it's a balanced system.

[geoff]

In message , Ray writes

It's only idiots like me who can't be arsed to look further who are willing to pay RS prices on something like that

[Julian Fowler]

LOL ... yes, you want to avoid anything that resembles two paper clips joined by wet string, but otherwise a cable is a cable is a cable. Those who would tell you otherwise are either (a) trying to con you into purchasing the latest 0.000000000001% oxygen with added snake-oil connects, or (b) have already been conned by (a) and want to disguise their embarrasment. Recording studios buy exactly the kind of generic screened cable and connectors available from RS, Maplin, etc., and get a spotty studio junior to make up cables - anyone with even a passing acquintance with a soldering iron can do the same.

Julian

[anyone]

O well, if the company doesn't pay, then yea :)

[David Robinson]

Have you heard the quality of UK DAB broadcasts? You don't need to spend much!

However, as the original poster has probably figured out already, he does need screened cable.

Usually - it depends. Which end you choose to connect can make a difference. Lots of fun!

UK wiring regulations mean you need to keep the audio cables at least

5cm away from any mains wiring.

Cheers, David.

[Dave Plowman]

R3 & 4 are still ok. But even at reduced bitrate, the frequency response isn't affected. And frequency response is the only likely thing to be affected by the use of the wrong cable - it's unlikely to cause any other forms of distortion. Driving speakers with long cables is a different matter - some poorly designed amps can become unstable with the load this may present.

[Neil Jones]

response

Yes, but if you're using Naim amps, you'll probably use Naim cables too, won't you?