Mods for the MXL 990 microphone

Discussion in 'Recording Studio' started by LeftyF2003, Mar 5, 2017.

  1. LeftyF2003

    LeftyF2003 Premium Member

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    A couple of years ago I picked up a near new MXL 990 for $25.00. After recording vocals for a couple of years with it stock I decided to try replacing the capsule with one from https://microphone-parts.com/.

    I ordered the RK-47 capsule and crossed my fingers. This capsule is based on the capsule that was used in the Neumann U47. The upgrade itself was a bit of a pain, mostly due to a cheap pot metal screw that was over-cranked when the mic was built which caused removing the stock capsule pedestal to take over an hour as I had to carefully drill the head off the screw to remove it. Otherwise it's a fairly simple matter of de-soldering the old capsule's hot and ground wires, mounting the new capsule using the including shoe and soldering the new capsule wires to the board. you can choose to either connect only one side or both sides of the capsule. If you are handy you could also add a switch on the edge of the board to turn one side off.

    Once I had this mod done I decided to also take the advice of another mod site and remove the inside mesh from the head basket. You can also order an upgraded head basket, but removing the mesh is easy enough and theoretically opens up the mic a bit more and removes some audible vibration that can occur with high volume sources like drums. The inner mesh is also too tightly weaved, the theory being that MXL did this to try and hide the tiny stock capsule. To do this, first break loose and edge of the inner mesh with an awl or a small flat head screw driver, then use some needle nosed pliers to pry the mesh out. I used some blue painters tape to protect the inner edge of the head basket while I did this.

    What a difference! The mic now sounds much more open and balanced, and is omni which can be very useful for recording things like room sound and drums. It's also a good choice for adding a second mic to the back of an open backed amp and setting out of phase.

    I don't have my camera handy but I'll borrow these pics

    This is the RK-47 upgrade capsule

    [​IMG]

    This is the stock capsule from MXL

    [​IMG]

    This is a pic showing the difference when removing the inner mesh from the head basket

    [​IMG]

    And here's a sample of a modded MXL 990 with the RK-47 capsule - this is the mic on the guitar

    [ame="http://www.youtube.com/watch?v=ojoqANAqE7c"]http://www.youtube.com/watch?v=ojoqANAqE7c[/ame]

    So in short if you pick one of these up used and replace the capsule you will have an amazing mic for peanuts. Hope this helps someone else
     
  2. kfowler8

    kfowler8 Senior Member

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    That's cool Fred.

    I did a similar mod to mine a couple of years ago. In additional to removing the mesh, I added mole skin to the inside of the housing and replaced a couple of capacitors. I left the capsule stock.

    It made a huge difference. The mic is much more usable and open. It also removed the "chu" sound I was hearing when used with drums. It was a very inexpensive mod. Maybe spent $10 total.

    I thought about trying the new capsule but my only hesitation is you still have to commit $150 for the new capsule and it doesn't really raise the value of the mic. From a useful practical standpoint though it makes sense.

    I have an MXL R40 ribbon mic I bought on a SDOTD from MF. I replaced the stock transformer with a Lundahl transformer. I think it was like $90. That made a huge difference. It actually sounds fantastic on guitar.
     
  3. LeftyF2003

    LeftyF2003 Premium Member

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    Thanks Kevin. Yea, I'm loving this mic now. Absolutely a different animal!
     
  4. kfowler8

    kfowler8 Senior Member

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    I'd be really interested to hear a comparison between what you did, a high end mic, a 990 with the mods I did, and a stock one.

    I have a friend with a stock one so I may try and borrow it to try some comparisons.

    BTW, I recorded with it this weekend using it as a bottom snare mic.
     
  5. LeftyF2003

    LeftyF2003 Premium Member

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    Nice! It's also a good acoustic guitar mic, though I mix it with an LR Baggs Piezo system into a Radial PZ-DI. You would really need all the mics in the same room with the same source to really tell the differences I think. I can send you some before and after vocal takes with it when I get them done, but my voice may not display any subtle changes in the mic! :laugh2:
     

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