Skip to content
Laptop recording is...
 
Notifications
Clear all

Laptop recording is electrifying!

9 Posts
5 Users
0 Likes
2,090 Views
Kroikey
(@kroikey)
Reputable Member
Joined: 15 years ago
Posts: 232
Topic starter  

HELP! :shock:

I want to record my guitar so I can recreate a nicely mixed song with singing (cant do both at once yet). However whenever I plug my electric guitar into the laptop, my electric guitar gets an electrical charge! The guitar isn't plugged into anything but the laptops mic/linein socket, so its definately coming from the laptop. Its quite strong too, because I can sense the field around the strings...

The damn thing is stopping me using Audacity to create some nice arrangements. Additionally I can't use any effects or amplification in the chain to the laptop or the recording doesn't work at all. How do people accomplish this without resorting to a microphone (which diminishes quality substancially I'm sure).

Thanks in advance! :mrgreen:


   
Quote
dogbite
(@dogbite)
Illustrious Member
Joined: 17 years ago
Posts: 6348
 

how strange. I use a digital interface. I also use a DI box. maybe a DI is what you need.??

http://www.soundclick.com/bands/pagemusic.cfm?bandID=644552
http://www.soundclick.com/couleerockinvaders


   
ReplyQuote
greybeard
(@greybeard)
Illustrious Member
Joined: 20 years ago
Posts: 5840
 

There should be no current flowing, other than that generated by your pickups, which is minimal. It may be an idea to get the laptop checked. If you have a multi-meter, you can check for yourself.

Don't plug the lead into the guitar, just into the laptop. Take the multi-meter and set the dial for 200V DC. Put one probe onto the sheath of the jack plug and the other probe onto one of the two top sections. See what it reads, then test the other top section (keeping the other probe on the sheath).

Now repeat the process, but reverse the probes.

It may be worth trying the same, but this time with your meter set to AC. Although this should never be a problem, computers work with DC @ 5V and 12V, usually.

Any result, other than 0V, is not good news.

Stupid thought, but are you sure that it's the line in, not line out or speaker out?

I started with nothing - and I've still got most of it left.
Did you know that the word "gullible" is not in any dictionary?
Greybeard's Pages
My Articles & Reviews on GN


   
ReplyQuote
gnease
(@gnease)
Illustrious Member
Joined: 19 years ago
Posts: 5038
 

It may be worth trying the same, but this time with your meter set to AC. Although this should never be a problem, computers work with DC @ 5V and 12V, usually.

Any result, other than 0V, is not good news.

Stupid thought, but are you sure that it's the line in, not line out or speaker out?

Assuming a typical laptop or PC, not entirely correct. Mono laptop mic inputs (but NOT mono or stereo line level inputs) are designed to bias external condenser mics with a DC voltage, and so typically provide anywhere from 3 to 12 DC at the mic input jack. However, this is through a current limiting resistor -- usually about 1k ohm. On a "stereo" Tip/Ring/Sleeve connector, that voltage appears on the ring; sleeve is ground and tip is AC coupled for the audio signal. Once plugged in with a correct adapter cable, a normally wired electric guitar should provide a moderate impedance DC path to ground for the Tip circuit, and some voltage could appear on the guitar -- but not on the strings, as they are grounded. And even if the adapter is incorrectly wired, that voltage through a 1k resistor (in the laptop) poses no serious danger and little damage potential -- again IF the resistor is correctly in place. If the laptop works with a cheap external mic, the laptop wiring probably is correct. In any case, I am surprised if you can feel this sort of voltage on an electric guitar given it's signal and grounding structure. The most probable way of getting voltage to the strings on an electric guitar would be if the adapter manages to connect the laptop Ring to the guitar ground. Seem most likely to happen if the plug is not fully inserted into the laptop.

On an acoustic/electric with a piezo bridge pup, it also might be possible to have 3 to 12 V "appear" on the guitar's strings for combinations of adapter type and insertion, string electrical connections.

One key aspect here is probably the type of adapter plug or cable used to connect the guitar to the laptop. If you are using a stereo (laptop, 1/8" side) to mono (guitar side) adapter, that adapter is probably connecting the Ring and Tip to each other through small valued resistors and this combined signal to the mono side Tip. This would connect the bias voltage to the guitar. Again, seems more likely to be noticed on an acoustic with piezo pup than an electric --- but hey ...

Recommendations:

1. Make sure your guitar to PC mic adapter from 1/4'' to 1/8" is Mono to Mono and NOT Mono to Stereo (not tip/ring/sleeve). As described above, some mono to stereo adapters may connect the tip and ring (from stereo side) together to create the mono signal.

2. Make sure the adapter is pushed all the way in at the laptop input. Same for guitar.

If none of this helps, buy and inexpensive USB audio interface and skip the mic input. That may only be $10 to $20 US these days.

Good luck.

-=tension & release=-


   
ReplyQuote
Kroikey
(@kroikey)
Reputable Member
Joined: 15 years ago
Posts: 232
Topic starter  

Thanks for the replies, especially gnease! That gives me more than enough information to move forward on this. I tried without the laptop being plugged in and got the same result, I got a small electric shock from the neck end of the guitar, so I'm pretty sure its making its way to the strings somehow. I've got two guitars, but forgot to try the other one as a comparison and wasn't too keen on another shock to be honest.

It seems this kind of problem is going to haunt me forever because I just spent three weeks getting a electric shocks everytime I got out of my car, damn those new trainers. The difference is that was static :lol:

I may just record everything through a mic, that way I can have all the effects I want too. Not sure the quality will be good enough for me, but hey ho. Thanks again all! :)


   
ReplyQuote
gnease
(@gnease)
Illustrious Member
Joined: 19 years ago
Posts: 5038
 

Thanks for the replies, especially gnease! That gives me more than enough information to move forward on this. I tried without the laptop being plugged in and got the same result, I got a small electric shock from the neck end of the guitar, so I'm pretty sure its making its way to the strings somehow. I've got two guitars, but forgot to try the other one as a comparison and wasn't too keen on another shock to be honest.

It seems this kind of problem is going to haunt me forever because I just spent three weeks getting a electric shocks everytime I got out of my car, darn those new trainers. The difference is that was static :lol:

I may just record everything through a mic, that way I can have all the effects I want too. Not sure the quality will be good enough for me, but hey ho. Thanks again all! :)

Plugged into an amp powered by AC mains? If so, you need to check your house wiring for reversed hot/neutral or other ground fault issues and/or your amp grounding. This is serious stuff. Spend $10 on a mains wiring tester. Might save your life!

-=tension & release=-


   
ReplyQuote
Kroikey
(@kroikey)
Reputable Member
Joined: 15 years ago
Posts: 232
Topic starter  

The guitar is totally unplugged, as I stated I can't get any amplification or effects to record except the guitar by itself. I've not tried my SG yet or plugging into my main machine (its too powerful and new to risk lol). I did try unplugging the laptops power supply and the problem was still there. I did manage to use a microphone to record some stuff (badly), I'll have to use some different interface or other in future.

Thanks for the advice.


   
ReplyQuote
Cat
 Cat
(@cat)
Noble Member
Joined: 14 years ago
Posts: 1224
 

So? Don't play it in the bath tub...

Cat

"Feel what you play...play what you feel!"


   
ReplyQuote
Kroikey
(@kroikey)
Reputable Member
Joined: 15 years ago
Posts: 232
Topic starter  

I get a real buzz from playing, no need to take it to the next level! :twisted:


   
ReplyQuote