Hi, I bought a Lexicon Alpha in order to use with Apple Mac (Logic). Now, my microphone is a dynamic microphone so it does not need any phantom power. When I connect the usb cable, the blue light comes up. The problem is, when I record on mono mode I get no signal or no audio wave on my computer. But, when I record on audio mode I get signal but only on the right side. I just don't understand the problem. I even tried it using the Lexicon Alpha with Windows (Cubase) I get the same problem, only right side records. Please help me any idea what the problem is. Thank You Mehmet

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.

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 will use microphone with balanced XLR connector into the XLR mic input. Note, the ALpha does NOT have phantom power so you cannot use condenser mics.

A guitar can be plugged into the hi-z instrument 1/4 inch jack on the left front of the unit.

To use the line 1/4 inch inputs you will use BALANCED TRS 1/4 inch cables from your source.for these channels. The level on these needs to be line level.

The line outs are for sending audio out to an amp. There appears to be RCA outputs you can use as well.

I am not sure what you mean by making your "amp record"... An amp PLAYS the audio, usually into a speaker.

If you are trying to play a guitar through your amp AND record, then you will connect your guitar to the Alpha, the amp input will have a cable from say Line 1 OUTPUT and when recording wou will have the echo feature on so your guitar is passed through to the amp.

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..

Make sure you have Phantom power turned on on the Lexicon... Oh,oh... it appears that the Alphs may NOT have phantom power which IS a REQUIREMENT for most condenser mics...

The Lexicon Omega does have this but apparently the Aplpha doesn't have it.

That leaves you with the choice of either getting a dynamic mic that doesn't need Phantom, or replacing the Alpha, OR using a preamp ahead of the mic before the Alpha...

Sorry, but those are the only solutions I see for you.

REMEMBER that condenser mics pick up everything and you cannot run them into a PA or they will feedback.

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

Check for ground loops.

You MIGHT be able to cut the noise by setting the EQ's to clip the highs.