MXL 990 - bad hum

H

hoursonend

Member
Hi,

I was recording something and discovered a hum sound, searched for it and found it to be the MXL 990. It sounds like it's not grounded, and when I get in close to the body of the mic with my hand, the hum gets worse, and when I touch the body of the mic, there is an explosion of hum, it gets really bad.. :confused:

If I touch the plug on the cable, the hum disappears (almost) completely...very strange....
Now I know that all the power outlets in my room are not grounded, I think that should have something to do with it? I don't have a different xlr cable to try if the problem's there, but I will have in a few days so I can test that...

In the mean time: any suggestions?

edit: it's not the preamp either, as I tested it through both my tube pre and my mixer...

Thanks,
Stan.
 
It could be groundlooping, check to see if moving the plug of the preamp to another outlet, that could be it, it could be a faulty cable, you need to get another to test it. Some people may blame the mic but I've had 2 990's and both were very decent for the small price and neither had any hum.
 
hum

stanjanssen said:
Hi,

I was recording something and discovered a hum sound, searched for it and found it to be the MXL 990. It sounds like it's not grounded, and when I get in close to the body of the mic with my hand, the hum gets worse, and when I touch the body of the mic, there is an explosion of hum, it gets really bad.. :confused:

If I touch the plug on the cable, the hum disappears (almost) completely...very strange....
Now I know that all the power outlets in my room are not grounded, I think that should have something to do with it? I don't have a different xlr cable to try if the problem's there, but I will have in a few days so I can test that...

In the mean time: any suggestions?



Thanks,
Stan.
Click to expand...

Mine did the same thing. I unscrewed the body and checked the xlr connector for a loose wire or some type of ground problem. But I found nothing.
I put it back together and it still hummed. I unscrewed the body just a little and the hum was gone. I still don't know why but it can't be screwed up all the way. It's still tight, just not all the way. Worth a try huh?
I think I had twisted mine trying to align the MXL just under the screen mesh with the mxl990 on the base of the mic.
 
ch2os7 said:
Mine did the same thing. I unscrewed the body and checked the xlr connector for a loose wire or some type of ground problem. But I found nothing.
I put it back together and it still hummed. I unscrewed the body just a little and the hum was gone. I still don't know why but it can't be screwed up all the way. It's still tight, just not all the way. Worth a try huh?
I think I had twisted mine trying to align the MXL just under the screen mesh with the mxl990 on the base of the mic.
Click to expand...

Yeah! this actually worked! Thanks! I would never have thought about that...
I did the same thing: align the MXL logo with the 'mxl990' on the base...

Oh well, glad it's gone :)

Thanks again!

Stan.
 
Weird! Funny how twisting the grill makes the hum go away. All in all what do you guys think of the mic.
 
I think it's a nice mic, but I'm not that reliable as the 990 is at the moment my only condenser, apart from an MXL 991, and I never had or thoroughly tested any other one. I think the pre you use makes a big difference, but I guess that's the case with most condensers. All in all I'm very satisfied with the deal I had on ebay, the two mics for $80 or so. I'm very satisfied with the two mics and not planning on buying any other condensers for some time, I like the sound of the 990 on my voice, maybe I'll post some clips some time.

Thanks for your input, both of you :)

Stan.
 
mxl990

jonnyc said:
Weird! Funny how twisting the grill makes the hum go away. All in all what do you guys think of the mic.
Click to expand...

I like the mic. I have gotten some decent recordings with it. It's really not a bad mic for the money. I've used it mainly on mandolin and acoustic guitar. I have a few other LDC's so I use the 990 sparingly.
 
hey thanks- this really helped me out too.
actually i like the mic. mine is a little noisy (might be partially a phantom power problem) but works well for my vox- quite warm and reasonably detailed- and also on my acoustic (an old hofner f-hole semi).
i also have an nt1a- incredibly quiet, and a much "better" mic- the detail is superb- but I find it too "darK" for my voice (really nice on my 11-year-old daughter tho.) when i bought it and on first use, i just thought it was amazing (it is), and the "colour" wouldn't be an issue. now I only use it on vox when i want dark- mostly i use the mxl990. odd, really, how important that turned out to be.
 
hey robstowell, the 'noisy' bit of your post; does that refer to some rumble, noisy sound? Beause mine does that too... I'll post a clip this weekend or so....
 
MXL 990 in session yesterday....

My band recorded a song yesterday in our bass player's other band's practice space. They have a nice little setup, P4 PC, cubase SX 3, Mackie 1604 mixer, MOTU 24I/O. I have a small home recording set-up, I brought along my Soundcraft Compact 4, and my mics, the drummer brought his mics and we went to it.

I have recorded in a handful of professional studios, and by far this is already the best sounding track (pre mixdown), I have been involved in.

The biggest surprise of the day was my mxl990. We were setting up the bass, the bass player wanted to go strictly DI, but I have a thing for micing amps whenever possible, particularly on bass. I was hesitant to use the mxl990 but we were short on mics. I set it up about a foot in front of the bass cab, off to the right a little just above the middle line. We put a piece of 3' x3' sheet rock that was laying in the hallway about 10" behind the mic to somewhat isolate it from the bass drum. We always do Drums, Bass, and Guitar live, all at once, its the best way, in my opinion, to get a good organic groove.

Anyway, we used the DI and the 990, and I got to say the 990 sounds fantastic. It sounds huge and earthy, mixed with a little of the DI the bass sounds great, almost in a ratio of 4:1, 4 parts mic to 1 part DI.

Also, as a note, I took the first two layers of grille off of the 990 as some people around the web have said to do. Its hard to say at this point if that has made a big difference, because I never recorded bass with the 990 until yesterday.
 
I just bought the MXL 990 & it has a Very Loud Hum. The Mic works but recording with it, is not an option. Was your hum a Loud One. tried Twisting it & taking apart, but it did not help. I'm plugging it into a Fostex 450 Mixer & I've never used the Phantom Power until now. No matter what I do, I got the very Loud Hum. Any suggestions ?
 
i tried typical troubleshooting such as new cable. it's not the cable. i think it's the phantom power in my Fostex 450 mixer. With no Mic connected, as soon as I turn Phantom Power On, I get a similar hum only lower in volume. With no mic connected. Just by Turning Phantom Power On in that Channel. Tried all the Channels on Mixer. Same problem. Guess I need a new Mixer, or a Separate Phantom Power Box.
 
How old is the house? It could be that there's no actual ground in the plugs. Not that it's easy to come by, but a battery and inverter might be worth a test. Or just one of those backup PSU's that you get at office depot/max. They only last 5 to 20 minutes in most cases. But if it solves your ground issue, you identified that as an issue. I just use a field recorder, but I don't need to multi-track (yet). Battery powered, so a lot of those power issue go away.
 
Fix for MXL 990 hum problem!

Hey everyone, I found this forum while searching around for info on the MXL 990 regarding a bad humming problem. I believe I fixed mine so I had to join up and share what I found.

I was sure the hum was due to a grounding problem because of the sound, and touching the casing or the connector on the mic cable would chang the sound of the hum... so I figured I had nothing to lose and opened the mic up. First I resoldered the ground lead at the circuit board, but it looked fine and I don't think that's what the problem was... I looked at the windscreen assembly, and where the screws go up through the chassis and circuit board to attach the windscreen to the mic, there's an area around the screw hole that needs to make contact with the board to make ground... when they painted/coated the windscreen assembly they painted over that area... I scraped the area around the screw holes on the windscreen to expose some bare metal and re-assembled the mic and bam! Dead silent.

I've read other complaints of these mics humming... hope this helps... super easy fix, no soldering necessary... pass it on!!
 
Last edited:
You must log in or register to reply here.
Back
Top