Line-level signal into laptop's 1/8 jack? at DVinfo.net

Alex Raskin · August 21st, 2009, 01:31 AM

Surely this is a bad idea since 1/8" line-in (shared with mic/in) jack on the laptop is fiddly.

But, I don't have a leeway to use a USB or firewire interface in my situation.

So... have to use the laptop's existing internal card and jack.

Is there a way to somehow reinforce the mini jack, to make it less prone to bad contact/crackling?

My signal source is the output of Mackie 402 VLZ3 mixer.

Thanks!

Josh Bass · August 21st, 2009, 01:40 AM

Couldn't tell you, but I have heard from local sound guys that if an input isn't an XLR or 1/4" input, it's probably "consumer" line level as opposed to real line level (I think consumer line level is -10, while "real" line level is +4, or some such. The point is, consumer is way more sensitive, TOO sensitive for a real line level signal). The XL2 camera suffers from this, as does my Imac. This is not to say you can't use line level devices, but you have to attenuate their output to prevent distortion.

Steve House · August 21st, 2009, 04:07 AM

As Josh said ... the laptop's input will be -10dBv consumer level while the Mackie main output will be +4dBu. The "crackling" may well be clipping rather than a poor mechanical connection. Take your signal from the Mackie's "tape out" RCA jacks as they will also be consumer level and see if it alleviates the problem.

Alex Raskin · August 21st, 2009, 04:26 AM

Thanks.

Steve, in the meantime I read your posts on the subject, and got warmed up to 1/8" adapter.

But with a twist.

I'm getting a PCMCIA interface card Indigo IO, and will feed Tape out from Mackie into it using RCA to 1/8" adapter.

Should work, I think. Indigo's specs are great, should be much better than laptop's.

Steve House · August 21st, 2009, 07:03 AM

Quote:

Originally Posted by Alex Raskin

Thanks.

Steve, in the meantime I read your posts on the subject, and got warmed up to 1/8" adapter.

But with a twist.

I'm getting a PCMCIA interface card Indigo IO, and will feed Tape out from Mackie into it using RCA to 1/8" adapter.

Should work, I think. Indigo's specs are great, should be much better than laptop's.

I agree - I have both an AudioFire 12 and and an AudioFire 8 and I am quite pleased with Echo's products. While I haven't used one I would expect the Indigo to be equally as good.

Jay Massengill · August 21st, 2009, 10:58 AM

Mackie tape out RCA connectors are usually higher in output than -10db. If I remember correctly from the past, around 0db. So you should still listen for clipping if you're connected to a sensitive input.

Steve House · August 21st, 2009, 11:01 AM

Quote:

Originally Posted by Jay Massengill

Mackie tape out RCA connectors are usually higher in output than -10db. If I remember correctly from the past, around 0db. So you should still listen for clipping if you're connected to a sensitive input.

Still listen ... absolutely! But my Mackie lists the tape outs as being consumer line level. OVU on the meter is 0dBu on the main outs, true, but the tapes are spec'ed at the lower line level.

August 21st, 2009, 01:31 AM	#1
Alex Raskin Trustee Join Date: Sep 2003 Posts: 1,435	Line-level signal into laptop's 1/8 jack? Surely this is a bad idea since 1/8" line-in (shared with mic/in) jack on the laptop is fiddly. But, I don't have a leeway to use a USB or firewire interface in my situation. So... have to use the laptop's existing internal card and jack. Is there a way to somehow reinforce the mini jack, to make it less prone to bad contact/crackling? My signal source is the output of Mackie 402 VLZ3 mixer. Thanks!

August 21st, 2009, 01:40 AM	#2
Josh Bass Slash Rules! Join Date: Apr 2002 Location: Houston, Texas Posts: 5,472	Couldn't tell you, but I have heard from local sound guys that if an input isn't an XLR or 1/4" input, it's probably "consumer" line level as opposed to real line level (I think consumer line level is -10, while "real" line level is +4, or some such. The point is, consumer is way more sensitive, TOO sensitive for a real line level signal). The XL2 camera suffers from this, as does my Imac. This is not to say you can't use line level devices, but you have to attenuate their output to prevent distortion. __________________ The Bass' camerawork The Bass on IMDB

August 21st, 2009, 04:07 AM	#3
Steve House Inner Circle Join Date: Mar 2005 Location: Hamilton, Ontario, Canada Posts: 5,742	As Josh said ... the laptop's input will be -10dBv consumer level while the Mackie main output will be +4dBu. The "crackling" may well be clipping rather than a poor mechanical connection. Take your signal from the Mackie's "tape out" RCA jacks as they will also be consumer level and see if it alleviates the problem. __________________ Good news, Cousins! This week's chocolate ration is 15 grams!

August 21st, 2009, 04:26 AM	#4
Alex Raskin Trustee Join Date: Sep 2003 Posts: 1,435	Thanks. Steve, in the meantime I read your posts on the subject, and got warmed up to 1/8" adapter. But with a twist. I'm getting a PCMCIA interface card Indigo IO, and will feed Tape out from Mackie into it using RCA to 1/8" adapter. Should work, I think. Indigo's specs are great, should be much better than laptop's.

August 21st, 2009, 10:58 AM	#6
Jay Massengill Trustee Join Date: Jul 2003 Location: Burlington Posts: 1,976	Mackie tape out RCA connectors are usually higher in output than -10db. If I remember correctly from the past, around 0db. So you should still listen for clipping if you're connected to a sensitive input.