990 Mod Kit


Please note that our mod kits only work on versions of these mics that use through-hole components (as opposed to surface-mount or SMT). Please consult the Compatibility page for complete details.

$9.99 for first kit + $7 for each additional kit ordered.

Domestic U.S. Shipping is free.

For International Shipping outside the U.S., please also click the “Add to Cart” button below for “Add International Shipping to your order”.

Our original “990 mod kit” works with the following makes and models of small, medium, and large-format condensers:

MXL: 990, 991, 992, 993, 920, 770, V57M, V63M, V93M, 2003 (the original, NOT the newer 2003A), 1006, 2006, V250, MCA SP-1, Mix UA-1, 441, 551, 600, 603, 603S, 604, CR24P
797 Audio: CR1-4
Advanced Audio: CM-54
ADK: SC-1, SC-2, SC-T
Alctron: HSMC001
AKG: Perception 170 (the older “Perception 170”, NOT the newer “P170” that replaced it)
AMT: 404
Apex: 180, 185, 435
Audio 2000: ACM1901
Badaax: CM40, MC001
Busman: BSC-1
CAD: GXL1200, GXL2200, GXL2200BP, GXL2400
Carillon: AXIS 1
Cascade: M37, M39
Eagletone: CM40
Felio: CR1-11, CR1-14
KAM: i2
Monoprice: 600700, 600800
Nady: CM90, CM95, SCM800, SCM900 (post-2002)
Peluso: CEMC-6
SE Electronics: SE1, SE1A, SE2A
T.Bone: SC400

Please note that this kit works only on the later, post-2002 version of the Nady SCM-900, which uses the same circuit as the MXL 990, 603S, MCA SP-1, and V63M, among others. Older pre-2002 versions of the SCM-900 featured the same circuit and transformer-coupled output as the MXL 2001. Those early versions can be modified using our 2001 mod kit.

This kit includes the parts needed to perform the mod on ONE MIC. If you wish to modify more than one mic, you’ll need to order a kit for EACH MIC. Each kit includes the following parts:

  • (1) polystyrene (styroflex) capacitor
  • (2) metal film capacitors
  • PDF download with 13 pages of newly-revised, detailed, illustrated instructions for performing the mod on each of the 3 basic variants of microphones represented above: small, medium, and large-bodied mics.
  • BONUS: Detailed, illustrated instructions for how to perform the popular headbasket mod on the medium and large-format mics (included in the PDF instructions)

To perform the mod, you will remove two capacitors from one side of the printed circuit board and replace them with the metal film caps. Then, you will remove the ceramic capsule/gate cap from the opposite side of the circuit board, and replace it with the polystyrene cap. These capacitors are non-polarized, so it doesn’t matter which lead you connect to which side.

Most who have performed this mod say it takes about 15 to 20 minutes per mic, and makes a significant improvement in the sound.

Click here to read some testimonials.





Number of Kits

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