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Ships to:
United States
Ships to:
United States

Details about  Mod Kit for MXL 603 603S 604 990 991 CAD GXL1200 Nady CM90 Apex 180 Microphones

Mod Kit for MXL 603 603S 604 990 991 CAD GXL1200 Nady CM90 Apex 180 Microphones See original listing
Item Sold
Item condition:
Jun 30, 2012 06:31:25 PDT
US $7.49
FREE Economy Shipping | See details
Item location:
Arkansas, United States


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Seller assumes all responsibility for this listing.

Item specifics




This kit includes the parts needed to perform the popular mod for the mic models listed above that you've probably read about on various recording forums. It also works on the CAD GXL 1200 and the Nady CM-90, which share the same internal design as the MXL mics.

This kit includes the following, which is required to perform this mod on one mic:

  • (2) Panasonic Metal Film capacitors
  • (1) Styroflex Polystyrene capacitor
  • Downloadable PDF with detailed instructions for performing the mod

To perform the mod, you simply remove the 3 stock ceramic capacitors and replace them with the ones included in this kit. Specifically, you remove the ceramic caps (labeled C3 and C4 on the printed circuit board) and replace them with the Panasonic Metal Film caps. Then, you remove the ceramic capsule/gate cap (labeled C13 on the back of the printed circuit board) and replace it with the Styroflex polystyrene cap. These capacitors do not have a polarity, so it doesn't matter which lead you connect to which side.

Upon receiving payment, I will mail your kit/s and send you a link to a website with detailed instructions. NOTE: The link to the instructions will be included in the e-mail message that you will receive from Paypal that also contains your shipping info and tracking number. Most who have performed the mod say it takes about 15 minutes and makes a noticeable improvement in the sound of these mics. I personally did the mod on my 603S Pair. I've got a lot of experience soldering my own cables, but very little experience soldering on printed circuit boards. I had never done a mic mod before and was a little unsure of myself on the first one, so it took me about 20 minutes. However, I breezed through the second one and had it done in less than 10.

If you've been wanting to try your hand at an easy do-it-yourself mic mod, this is a great first-time project. These MXL Mics can be had for very little cash (new or used), and their performance can be improved considerably with this simple mod. These parts are hard to find, and frequently out-of-stock at major electronics suppliers, but you can get them here while they last!

Here's what some folks have said after performing the mod:

"After those 3 simple cap changes the already decent mic becomes wonderful. I will be using thes mics more and more."

"It helped smooth some of the harshness in the HF region."

"A little less "honky" in the midrange...overall, I think the mod is definitely a positive improvement to the mic."

"Nice mod, seems to open up the low end especially."

"I noticed that voices became less harsh in the upper mids.  On acoustic guitar, the initial attack of the notes changed to a smoother sound. It's hard to hear at first, but once you do you can't not hear it."

"The difference is in what people like to call resolution or detail. Better caps remove artifacts that lesser caps produce and that you only begin to hear once they're gone, because you thought they were part of the signal. There is a certain nasal quality that disappears with polyprop or polystyrene. It's probably something in the realm of distortion and/or transient response. I have no means to measure that, but you can hear it."

"The unmodded mic makes the guitar sound a little nasal, narrow and compressed. When you switch to the modded mic, it's almost as if the guitar had a bigger body. I could hear the difference both on headphones and my monitors."

"After getting used to the modified mics the unmodified mics sound like the high end is drifting in and out of phase or something.  Almost like it has a bit of flange on it.  The modification eliminated this.  I didn't notice until after the mod...but once I heard it I couldn't NOT hear it."

"...makes a 50 dollar mic sound like a 1600 dollar one!!!"

Note: This mod does require some basic tools and soldering skills! If you aren't comfortable performing the mod yourself, I also offer a mod service in which case I will do it for you. Contact me for more details. 

Feel free to ask questions.

I ship only to the lower 48 states.

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