MXL 990 Microphone Mods

Depending on who you ask, the MXL 990 is either awful or amazing. I have mixed feelings about these mics. Despite their shortcomings, no one can argue that they are immensely popular. They come at a price point which puts them in the hands of many thousands of musicians, singers, producers and engineers. They’ve helped launch the career of many and are probably heard on a surprising number of hits. For MXL to put a functional, entry level mic into the hands of so many is pretty amazing. For that, I have a lot of respect for this mic.

The other positive thing I will say about them is that mechanically, they are robustly built considering the price point. Every time I work on one, I am amazed that it has a street price of under 100 bucks (including case and shockmount). Unlike a lot of other low cost mics, the 990 has a pretty heavy body cylinder and a professional feel and weight.

mxl 990 mod
A finished and pretty rebuilt MXL 990

On the down side is that you get what you pay for. The MXL 990, oft marketed as an LDC, is actually not. The capsule is a small 24mm capsule and similar to what you find in the 910m 550, 440m, v250 and various other models. The circuit is a garden variety Schoeps-derived board and depending on the vintage, the components are either surface mount or low-end thru-hole stuff. MXL knows how to cut corners to make this price point! The stock tone of MXL990s tends to be thin, harsh and sibilant.

That Headbasket…

It’s almost like they didn’t want the mic to look too good. The form factor of the mic is sort of short and fat like a Neumann M49 and that gives it almost a cool look. But that headbasket is pretty ugly. Not only is it ugly, but they put three layers of mesh in the screen! Despite their best efforts, some sound does actually manage to make it to the capsule.

So, What Do We Do?

In all cases, I will replace the tiny MXL 990 Capsule with a good quality 34mm LDC. I mount the capsule in my own custom designed cradle but reuse the MXL base and post which is actually quite a slick design.

Since the beginning, I’ve had a version of my jaSb (just another Schoeps board) which is designed to fit the MXL990 (this board also fits the very rare MXL 920). This is the transformerless solution and I typically pair it with a K47-style Center-Terminated Capsule. The jaSb board will also work with a CK-12 style Edge-Terminated Capsule with a minor alteration.

mxl990 circuit
Standard MXL 990 board(L) and our jaSb all discrete board (R)
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Here is a short before/after video I did with a Transformerless MXL 990 Mod I did. The guitars, Bass and Vocals are all recorded with both versions of the mic and we switch back and forth. The difference is quite astounding I think. There is NO EQ on any of those tracks on either version of the mic.

Our transformer-coupled circuit – the BFM (Big F’n Microphone) is also available for the 990 (and 920). So we have an option to transformerize your MXL 990 with choice of high quality transformers from CineMag, 3U Audio and AMI. This greatly expands the color palette for these mics. These also have an optional internal pattern switch so you can switch the mic into omni mode when you need it.

mxl 990
The BFM-990 Transformer Coupled Board

Headbasket Options

The MXL 990 is one mic that really needs some attention to the headbasket. As I said above, the stock one is awful. Fortunately, we have a couple of options. The first is to use the awesome replacement headbasket from They look and function beautifully. I normally have a couple in stock for mods or this is also something you can order from them and do yourself any time. It gives the mic a really slick professional look.

The other option is to just make the existing headbasket suck less. This is a trick that lots of people do and it simply involves removing some layers of mesh from the screen. It’s a bit of a struggle, but I’ve done enough of them now that I’ve got it down.

mxl 990 mod
Mic-Parts Headbasket (L) and Modified MXL Headbasket (R)

Is a MXL 990 Mod Right For You?

If you’ve got an MXL 990 and are not using it because of it’s flaws, this is very affordable way of turning it into a go-to mic that you will find lots of uses for. On the other hand, if you are using it and thinking of selling it to get something better, doing this upgrade is a pretty good and very affordable option. The result is a pretty significant upgrade! Check out the mic mod service page for more details or contact me with any questions!

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