Headphone output lexicon mx 400 - Lexicon MX400 FX unit (with )

you have to set a master and slave(s) devices, and ensure that all the timings (16/24 bit, the 44.1/44/96k) are consistent in all devices

If unt was dropped, look for broken PC board in the vicinity of the rotary encoder. Also look at solder connections to make sure they are sound. A little contact cleaner applied to encoder through an opening so the spray gets inside will help clean contacts. If the knob itself is hard to turn, the shaft is likely bent, and there may be damage to the encoder itself.

you want no inputs headphones on the outputs and 4.1 on the last one and then select the hercules 4mx from the dropdown and apply and close

Does it buzz through cans? (headphones). Try listening on headphones (turn off any amps and speakers) on cue to each channel you use and to the master output. is it stil there? if so it's an all round earthing fault. If it's all good through the cans (sorry...I mean headphones), try it with the amp/s on again. If the buzz is back it souds like the screen on the main audio output connecters has come off inside.
It's a quick fix, but if you have never used a solder iron, take to someone who has.

Well, did you run the vocals through a mixer and send to BOTH channels of the Lexicon Alpha? If you connect the mic to only one channel you will only get one channel UNLESS you process the .wav file and PAN the vocal channel into both channels when outputing to your MP3.

The probable cause is a ground loop. You haven't said what you are plugging in. These inputs are BALANCED lines and you MUST use TRS cables driven by TRS outputs of the thing you are driving it with. ALL interconnected equipment MUST be powered by the same receptacle or power source.
IF the thing you are driving it with does not have balanced outputs, then procure a DI (Direct Input) box and use an XLR cablle between the DI and the Alpha and set the DI on ground lift.

You should be at SP2, but that MAY NOT be the problem. One thing to check is if you are supposed to have the device connected when you install the software... in SOME cases doing it with or without connection will affect the outcome. Also make sure ALL virus/spyware/popup blockers are disabled during install.

Before using this device, make sure that going to the control panel and looking at the "Sounds and Devices" shows that the Lexicon is the inout and output device for all the tabs within that window.

Make sure that when opening the control panel and "Sounds and Devices in Windows that both the inpout and output show the Lexicon and NOT the normal audio of the computer. ALso make sure the volume slider in that section is shown as being full up.

Please try a set of headphones. If it is balanced in the phones, then I suspect trouble might be in the muting circuits of the main output.

Next test is to verify the outputs using direct inputs to the CD input...

First verify that one channel is bad by swapping the output leads and seeing the bad audio comes from the other speaker. Assuming it does, you probably have a bad output driver on one side.
This can happen if one powers part of the system from different receptacles in a venue and electrical disturbances destroy one or more audio interconnects. ALWAYS power ALL interconnected equipment from the same source, even if you have to run an extension cord between power amps and the mixer.
You will probably need to take the unit for repair. The parts cost should be nominal, however labor could cost a bit.
Find out is SAME distortion is present in the headphone output. The circuitry shows a bunch of muting transistors and one of them could be bad... but we can do some troubleshooting externally with testing at headphone jack, etc.