Computer Related > Converting headphone out to line out Miscellaneous
Thread Author: Mike H Replies: 11
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New Mon 22 Nov 10 09:33 
 Converting headphone out to line out - Mike H
My laptop doesn't have a line-out, which I need to play it through my amp. Is there any trickery I can do with the headphone-out (which I do have) to make it compatible with the line-in on the amp?

(Yes, you're right, this is a followup to a previous thread a couple of months ago).
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New Mon 22 Nov 10 09:43 
 Converting headphone out to line out - Focusless
>> Is there any trickery I can do with the headphone-out (which I do have) to
>> make it compatible with the line-in on the amp?

Excuse my ignorance Mike but what's the problem? Finding the right connector, or some sort of levels issue?
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New Mon 22 Nov 10 09:52 
 Converting headphone out to line out - Bromptonaut
Maplins or similar will sell you a 3.5mm jack to line (white/red RCA connector) lead. Never used it to connect a PC but it works fine for linking MP3 players to the amp.

Needs full volume to get an acceptable level on the amp input.
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New Mon 22 Nov 10 10:05 
 Converting headphone out to line out - Mike H
I've got one of these - I'm using it for the physical connection but it's the resulting sound that's the issue!
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New Mon 22 Nov 10 10:04 
 Converting headphone out to line out - Mike H
The problem is simply that there is a lot of hissing when I connect the laptop to the amp via the headphone-out on the laptop into phono-in on the amp. I'm guessing that there is some sort of basic incompatibility (impedance, signal levels etc?). Not being an audio expert, but understanding the basic principles, I can't guess at what the problem is. I have tried adjusting sound levels on both bits of kit but the loud hiss is still there.
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New Mon 22 Nov 10 10:26 
 Converting headphone out to line out - spamcan61
Yes there is likely to be a significant difference in level and impedance, headphones are generally a few ohms or tens of ohms, a line input should be thousands of ohms. So this can make a difference, depending on how ell the the audio output in question is designed to cope with different levels/impedances.

Another approach would be to try one of these cheapo USB external sound cards, which are designed to do pretty much what you want to do, although I have no personal experience of the one linked below, it's just an example:-

cgi.ebay.co.uk/NEW-EXTERNAL-SOUND-CARD-USB-6-CHANNEL-5-1-AUDIO-S-PDIF-/360320337097?pt=UK_Computing_ComputerComponents_SoundCards&hash=item53e4c404c9

These ones are cheaper still but I'm not sure if it will drive a line in properly:-

cgi.ebay.co.uk/USB-EXTERNAL-3D-5-1-CHANNEL-AUDIO-PC-SOUND-CARD-ADAPTER-/370437380887?pt=UK_Computing_DesktopComponents_RL&hash=item563fc9db17
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New Mon 22 Nov 10 17:00 
 Converting headphone out to line out - Mike H
Thanks spamcan, took a quick look at these but I can't see a line out on the first (I realise it's only an example), and nor does the second.

I took the plunge and bought one of these this morning, although for some unfathomable reason it has since gone up by c.£8:

www.amazon.co.uk/Q-Waves-Wireless-USB-HDMI-Extender/dp/B002RL9F38/ref=sr_1_1?ie=UTF8&qid=1290444948&sr=1-1

Expensive yes, but it solves other wiring problems as well as giving me what I want. It remains to be seen how it works, but it seems to get good reports.
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New Mon 22 Nov 10 18:36 
 Converting headphone out to line out - spamcan61
>> Thanks spamcan, took a quick look at these but I can't see a line out
>> on the first (I realise it's only an example), and nor does the second.
>>
The 'front' outputs on the first one should give you line level 'normal' stereo; on the second one maybe the 'headphone' output is good enough, maybe not.
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New Fri 26 Nov 10 19:56 
 Converting headphone out to line out - Biggles
Is the port on the amp an aux input or actually a phono? If the latter, my recollection is that it is not well matched to a headphone signal. Can you try one of the other inputs?
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New Wed 24 Nov 10 19:15 
 Converting headphone out to line out - J Bonington Jagworth
The audio amps in laptops are nearly always horrible. There are lots of square waves and chopped power supplies in computers and they don't co-exist very happily with low-noise analogue circuitry. USB adaptors are usually the answer, as you have discovered (it should work well at that price!)
Last edited by: J Bonington Jagworth on Wed 24 Nov 10 at 19:17
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New Wed 24 Nov 10 21:20 
 Converting headphone out to line out - Tooslow
Cheap stuff.... :-)

www.whathifi.com/Review/Naim-DAC/

John
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New Thu 9 Dec 10 14:03 
 Converting headphone out to line out - spamcan61
Just a follow up for the sake of future Googlers.

I bought an external USB soundcard the same as the first one I linked to above, a whole 8 quid delivered from China. Took about 10 days.

Worked straight off on my XP laptop, needed (supplied) drivers installing for Vista. Now using it to copy cassettes onto my laptop. Need to make up another stereo 3.5mm to twin phono lead now.

Bargain!
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