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Non functioning Left Channel on recording.
Posted: Mon Jun 28, 2010 1:59 pm
by jumbuck70
I have a macBook Pro with Snow leopard, latest version and 1.3.12 Audacity Beta. My problem is, and it has happened once or twice before, that when recording from Vinyl played on a stand-alone record deck the left channel is completely dead as the proverbial Do-Do. The trace of that channel is just a straight line with nothing from the laptop left speaker but both channels working on my Hi-Fi speakers. I checked and rechecked Audacity preferences and the mac's sound device, all ok. The last twice it happened it appeared to right itself, but not this time, hence my plea for help. Thanks in anticipation.
Re: Non functioning Left Channel on recording.
Posted: Mon Jun 28, 2010 2:28 pm
by kozikowski
What kind of turntable is it and how is it connected to the Mac? USB? Analog audio cables? External Preamp?
Koz
Re: Non functioning Left Channel on recording.
Posted: Mon Jun 28, 2010 2:45 pm
by whomper
did you check teh cables and connectors ?
sounds like a bad connection is intermittent.
could be the sound card - bad component - heat sensitive - intermittent
could be the stand alone deck electronics are dying.
when it happens switch the cables to the inputs
and see if the other channel is dead eg they problem switches channels
if so remove the cable on the dead channel and try another one
Re: Non functioning Left Channel on recording.
Posted: Mon Jun 28, 2010 8:10 pm
by kozikowski
<<<could be the sound card - bad component - heat sensitive - intermittent>>>
Probably not. This is a Mac, not a cheap sound card. This is also the connector that has the optical SPDIF in the back as well as stereo Line-In -- dual purpose.
I have had problems where the connector doesn't go all the way into the socket, but that usually kills the right channel, not the left and it can screw up the one channel you do get.
Let's see how the poster is connected.
Koz
Re: Non functioning Left Channel on recording.
Posted: Mon Jun 28, 2010 10:03 pm
by whomper
i would still like to rule out the cables and the player.
Re: Non functioning Left Channel on recording.
Posted: Tue Jun 29, 2010 1:10 pm
by jumbuck70
Hi kos, Turntable is a Linn LP 12 which has just been serviced and is working ok. I have checked all connections and everything seems ok but will do so again. I have removed the Line-in jack and plugged it back in again without any difference.Will try another Input on my Preamp ( Naim 82) and get back to you. I appreciate your help.
Re: Non functioning Left Channel on recording.
Posted: Tue Jun 29, 2010 1:34 pm
by jumbuck70
Hi kos and whomper,
I have just unplugged and replugged the cable from the Preamp to the mac, fired up audacity, stuck an LP on the deck and bingo left channel fully functional once more. Thanks, can I ask you one more question about recording from the record deck into the mac but instead of using the Line-in, using a Stand-alone DAC unit plugged into the mac via USB. The DAC is a Firestone Fubar 0/1. My problem is that I cannot get a loud enough input on recording from vinyl to be able to transfer it onto CD. When you use the USB connection the sound device's controls are blanked out on the mac and I cannot figure out how to increase the sound input. I did the simple thing of turning up the volume, which did not work. Any ideas. My DAC is a new one, and it is a bit frustrating that I can't use it.
Re: Non functioning Left Channel on recording.
Posted: Tue Jun 29, 2010 2:30 pm
by billw58
jumbuck70 wrote:The DAC is a Firestone Fubar 0/1. My problem is that I cannot get a loud enough input on recording from vinyl to be able to transfer it onto CD. When you use the USB connection the sound device's controls are blanked out on the mac and I cannot figure out how to increase the sound input. I did the simple thing of turning up the volume, which did not work. Any ideas. My DAC is a new one, and it is a bit frustrating that I can't use it.
That unit is for playback, not recording.
Are you saying that when you plug in the Fubar and select it as your output device that your recording level control becomes non-functional? You should not be able to select it as an input device since it does not support that function.
-- Bill
Re: Non functioning Left Channel on recording.
Posted: Wed Jun 30, 2010 12:10 pm
by jumbuck70
Hi bill,
Thanks for replying but this particular model of DAC does both, records and plays back. When selected the DAC produces such a low trace in Audacity that it is quite useless, and as I indicated I can see no other way to increase the input volume.

Re: Non functioning Left Channel on recording.
Posted: Wed Jun 30, 2010 2:43 pm
by billw58
jumbuck70 wrote:Hi bill,
Thanks for replying but this particular model of DAC does both, records and plays back. When selected the DAC produces such a low trace in Audacity that it is quite useless, and as I indicated I can see no other way to increase the input volume.

Yes, sorry about that. When you said "DAC" I assumed it was input only. You appear to have this device:
http://www.audiophileproducts.com/fubario The Fubar I-O which is a DAC/ADC.
Are you plugging the turntable directly into the device? If so, this is the problem. It is meant to receive a line-level signal. The specs say 2 V RMS input sensitivity. You'll need to plug your turntable into your pre-amp, then take the pre-amp out into the input of the Fubar. The user manual is not available for download from their site. You might want to call their toll-free number and confirm this.
-- Bill