Have just purchased lexicon alpha to use on a Mac. Having trouble just getting started. Have hooked up a nice condenser mic into the alpha through the mic input on the rear and cannot get anything on the mac using garage band. Very frustrating.

Are you trying to use the mic input on the back or plugging it into the instrument input on the front? If you use a low impedance mic with a quarter inch instrument input cord, you would need a transformer adapter to make the mic work on high impedance. Even if you put it on line in, you would still have to convert it. Only the XLR socket on the back will work on a low impedance mic.

The problem is the PC thinks the Mic is attached to the Alpha rather than through the USB directly.
The Alpha software probably ALSO assumes this. Look in the "Sounds and Devices" page of the control panel and check to make sure the appropriate device is selected for voice input. If you don't see the Mic selected, select it, and if it isn't in the list, then it needs a driver installed or activated. Often the PC's audio system wants to "fight" this and it takes some "persuasion" to get it to cooperate.

Sorry, but the Lexicon Alpha does NOT have Phantom power and you can't use a condenser mic with it without a Phantom power injector or preamp.
If you mean you have a Phantom power injector then it should be working. Do you have seperate mics for the two channels of the stereo? If you have only one mic, then only one side will record unless you set for mono recording and then dump the recording into stereo voa Cubase. I would recommend you get a small mixer... even a 4 channel one to use ahead of the Lexicon so you can mix and PAN your mics the way you want them. The recording and trying to control the panning in Cubase can be frustrating... The Lexicon really doesn't have anything built in to PAN the mic to the center when stereo recording. Small mixers are inexpensive and often you can find them used or in pawn shops for cheap.

Sorry, but the Alpha does NOT have Phantom power which IS required for a condenser mic.

You will either have to get a mic preamp that supplies phantom power or go to a dynamic type mic if you stay with the Lexicon Alppha.

First, I could NOT find an MXL99 microphone... IF you have an MXL990 microphone, you can STOP trying to have the Alpha read it because it won't !!! The MXL990 is a condenser mic and requires that Phantom power be supplied to it and the Alpha does NOT have Phantom power.
I have found a common problem on the audio interface inout is having to GO INTO the windows Sounds and Devices and verifying that under the VOICE tab, checking that the inout device is listed AND then checking the volume is turned up in that window... It seems like you have to verify everything and tweek a dozen places to get everything right to work. Having to look under the "VOICE" tab is not a good description of where the Alpha input control should be... so anyway, check that as well as it is not MUTED in that window. With Adobe Audition, make sure you set under the options, the "metering" to monitor the input recording level.

You should be using XLR to XLR cable from the ART to the Alpha. You need to have recording software and the driver for the Alpha correctely loaded. Verify that in the PC when you go to the control panel in Windows and click on the "Sounds and Devices Icon that clicking on the VOICE tab that the Alpha is listed as the default audio for both in and out.

Make sure you have NO antivirus/antispyware/antiadware or other resource hogging background programs running while processing the audio. These programs hog resources to the point that the buffering within the audio devices is overrun causing gaps.

Sorry but... Very simply, you CANNOT use a condenser mic with the Alpha since it does not supply the required Phantom power for the mic. You must step up to another interface to use condenser mics. You can use dynamic mics with the Alpha or other audio sources. I use a Roland/Cakewalk UA25E interface with condenser mics and also the Lexicon Omega which does have Phantom power for the mics..

The Lexicon Alpha does NOT have phantom power. The mic input expects a standard mic or a "self-powered" condensor mic. This means that you will neex external phantom power. There are power units available that use 9V batteries for this.

Dan

you can download and install the alpha driver here: http://www.lexiconpro.com/product.php?id=7#downloads