Mbox 3 mic inputs fouled

[tpann]

I have the Mbox 3 standard (not mini, not pro). Using it today, everything was working fine, then suddenly the mic inputs seem to have just broken. Using a condenser mic with 48v, when I turn the input volume up to a reasonable level, it severely distorts the input on analog 2; analog 1 sounds pretty good but the level is unacceptably low (quiet) even with the input turned way up. With a dynamic mic (SM58), I just get a very low, unintelligible fuzziness, even at the highest input volume, on analog 2; and again, decent sound on analog 1 but unacceptably low volume with the input turned way up.

Meanwhile, recording midi to an instrument track with my Axiom 25 works perfectly. Playback of all previously recorded files works perfectly. Superior Drummer sounds perfect.

Playing electric guitar, line in 1 sounds good into both front and back inputs. Line in 2 is very distorted into both front and back inputs.

My thought is the thing needs service or replacement. Am I correct? Or is it possible I've got a setting screwed up somewhere?

Thanks!

[flagship]

Hi,

I just bought my Mbox 3 about a week ago. Everything is working fine, I haven't had the time to use it until today as far as recording live instruments go. The playback is fin I can hear everything so I know it's nothing to do with drivers, CPU etc. I went to stereo record Guitar both condenser mics and line 2 is doing the same thing. Did you find a solution yet. Like I said, it's new straight out of the box which has been a huge mood killer for the recording sesh. Let me know if you come up with anything.

[albee1952]

More troubleshooting is needed here. Step #1: test the mic and cable on any other system(even a PA). If the mic and cable are good on another setup, try the same cable but with a dynamic mic(SM57, SM58, etc) on your rig. If that works, then you have narrowed it down to the phantom power. Don't forget 2 things: there is a button to select between the XLR input and the quarter inch input, and condenser mics must use an XLR-XLR cable(there is no phantom power on the quarter inch inputs).

[flagship]

Hi there,

XLR connectors are in good condition and are working properly (checked soldering to correct terminals also), same goes with cable. I've tried 3 seperate cables as well. The mics I'm using are nt4 and 87a which have both been used through a pa on a regular basis and both work fine. Haven't tried a dynamic mic yet but will do tonight, have a spare 57. I've made sure that the xlr inputs are selected on the mbox 3 before proceeding. One thing I've noticed is that on input 2 when you press in the limiter button on the mbox it makes a strange hissing sound (From a higher frequency going down for about 2 seconds) when engaging and doesn't happen like that on input 1 (48V or not).

Input 1 seems to be sounding fine through both XLR and jack inputs, although I have to turn up the gain to almost max to get the right amount of level on PT. The signal doesn't clip on either the mbox or PT but it's strange that you'd have to gain the condenser mics that much to get a normal amount of level (limiter both on and off on the mbox, clean channel, no inserts or sends in PT eg. dynamic or time based effects).

After some tests today recording through input 1 I realized the transients on the waveform are higher at the top and at the bottom they are different, like it's out of phase (recording though input 1, mono, out stereo, both 87a and tested both of the mics on the nt4 separately with phantom power on, same thing).

If I can't narrow it down to the 48V tonight I will re install audio drivers and see what happens.

I'll update you on any progress or findings.
Maybe I just bought a Lemon

[tpann]

Sorry to get back to this so late...

In fact I sent mine in to Avid and they fixed it. Luckily under warranty. No direct statements from them to the effect that the thing was a lemon but clearly it was.

I have had no additional problems to date. Oh crap, I think I just jinxed myself.