|
Help! White noise bursts with phantom-powered mic
|
View this Thread in Original format
| cryophonik |
Any of you guys have experience with condenser mics? I've been having a problem with my Mojave MA-201 fet that I bought brand new about 10 months ago. The mic has only been used in my climate-controlled home studio, never dropped, never hot-plugged, or otherwise abused/misused.
I've noticed that whenever I engage or disengage the phantom power (48v) I get a blast of white noise and the problem seems to be getting worse. I typically use this mic with my Focusrite ISA Two, but I tried using it with my SSL XLogic Alpha Channel a few days ago and noticed that it also gives me random bursts of white noise after the 48v has been engaged, but only with this particular preamp. So, I tried it with my MOTU 828mkII's mic pre and I get the same white noise when I engage/disengage 48v that I get with the ISA Two. Here's a recording of the white noise with the ISA Two, followed by the SSL, followed by the MOTU (see the comment bubbles):
So, to summarize, if I use this mic with my Focusrite ISA Two, MOTU 828mkII, I only get the white noise bursts when I engage/disengage phantom power, which fades away after a few seconds, and it's perfectly usable (no other white noise) aside from that. But, I continue to get random noise bursts (more like white noise sweeps) with my SSL Alpha Channel even after the initial phantom power noise fades out, so it's not usable with this particular mic.
My setup goes like this:
Focusrite ISA Two > MOTU 828mkII line input > computer
SSL XLogic Alpha Channel > MOTU 828mkII line input > computer
All units are powered from the same outlet (via cheap Furman power conditioners), which makes me wonder if it's a power issue, BUT:
Things I've tried:
- MA201 > Apogee One > MacBook Air in a totally different room running off the MBA battery - same white noise problem as with the ISA Two and MOTU pre's - suggests that it's not a power issue.
- different mic cables with the MA-201 fet - same white noise problem.
- different condenser and dynamic mics with all three preamps - no white noise with any of the preamps; only happens with the MA-201 fet.
Aside from the initial noise blast, the mic seems to work fine with my ISA Two and MOTU (and Apogee One), but not with the SSL. Any thoughts or suggestions? Thanks in advance. |
|
|
| optik |
post it in gearslutz - they'll know
it might just be that the mic needs time to settle - you shouldn't really be turning on and off phantom power over and over again.. |
|
|
| cryophonik |
| quote: | Originally posted by optik
post it in gearslutz - they'll know |
I posted there a few days ago, but only got one not very useful reply. I know it's a long-shot, but I figured I'd ask here because guys like RANN and a few others have a lot of experience with these sorts of issues.
| quote: | Originally posted by optik
it might just be that the mic needs time to settle - you shouldn't really be turning on and off phantom power over and over again.. |
The phantom power has to be turned on for the mic to work and I only use my mics during one or two sessions per week, so it's nothing extraordinary. It's pretty much standard practice to turn the phantom power on/off before connecting/disconnecting the mic (i.e., as opposed to hot-plugging it with the phantom power already on). Also, when I power down some of my preamps (e.g., the Focusrite), the phantom power is automatically disengaged and can't be engaged until after it's powered on again, so I have no choice (aside from leaving my preamp/mic on and connected at all times, which is obviously not an option for something that gets used so little). Besides, powering a mic on/off once or twice a week shouldn't be a problem for a $700 mic. I've owned dozens of other condenser mics over the last three decades that have been powered on/off hundreds of times without this sort of issue.
I'm thinking that the mic is shot, or slowly dying. Fortunately, it's got a 2-year warranty. |
|
|
| DJ RANN |
That's completely not normal. I have used that mic extensively for both male and female vox, and there's no way it should be making that noise - it sounds like a capacitor is on the way out.
I know of two major engineers that reach for that mic before anything from Neumann, unless someone is whipping out a vintage U47 etc. It's basically become the standard for a good quality condenser.
Mojave are really good about their kit/warranties so I would send it back. |
|
|
| aquila |
| I had an almost identical problem with a cheaper MCA mic. As Rann said, I suspect it's a dodgy capacitor in the mic. |
|
|
| PaULiN0 |
| Damn that sucks cryo, hope you get it sorted it out. |
|
|
| Trancelover03591 |
| Notice you have download available, k if I sample that? |
|
|
| cryophonik |
| quote: | Originally posted by DJ RANN
That's completely not normal. I have used that mic extensively for both male and female vox, and there's no way it should be making that noise - it sounds like a capacitor is on the way out.
I know of two major engineers that reach for that mic before anything from Neumann, unless someone is whipping out a vintage U47 etc. It's basically become the standard for a good quality condenser.
Mojave are really good about their kit/warranties so I would send it back. |
Yeah, totally agreed. This is by far the best sounding studio mic I've ever owned. I sold my AKG C414 right after getting this!
| quote: | Originally posted by aquila
I had an almost identical problem with a cheaper MCA mic. As Rann said, I suspect it's a dodgy capacitor in the mic. |
Cool, thanks for the input guys. I think I'll be sending it back. I bought it from Sweetwater and those guys are usually great about handling these sorts of issues, so hopefully they can get me back in business quickly - we're in the middle of recording an album and I don't want to be without this mic for more than a week or two!
| quote: | Originally posted by Trancelover03591
Notice you have download available, k if I sample that? |
Yeah, knock yourself out, Caleb! I was thinking the same thing, actually - authentic noise sweeps ftw! Just make sure that you credit Dave Royer's bad capacitors! :p |
|
|
| cryophonik |
| Just to follow up, the problem was covered under Sweetwater's 2-year warranty (and Mojave's factory 1-year warranty). Sweetwater couldn't ID the problem, but they sent it to Mojave and they replaced a capacitor and blew some dust out of the capsule. I got it back yesterday and it's good as new - no charge, quick turnaround. :) |
|
|
|
|
