Tutorial: KM84 Clone Upgrade

The microphone market is becoming more and more flooded with KM84 clones. And most are identical! In fact I have been able to tract down the OEM manufacturer for the most popular of these clones. 


Alctron makes most of the KM84 style clones on the market. In this case this article will speak to all the T01A / T02A rebrands. The T02A is the same ciecuit but offers a pad and low cut. Both can use the Alctron Omni, Cardiod, and Hypercardoid capsules.

Here is a list of rebrands of the T01A/T02A:

  • MXL 603
  • MXL 604
  • MXL 991
  • MXL 441
  • CAD GXL 1200
  • NADY CM90
  • Monoprice 600700
  • There are many more but these are the popular ones

The difference between any of these is minor. The most notable difference is how the XLR screws into the PCB inside the housing. Other then that they all use the same Scheops circuit for a low noise floor. The capsules are clones of the KM84. Those two combinations are why these clones surprise a lot of people considering their price.

Side note the MXL 990 and a lot of these discount rebrand Chinese LDC microphones use identical circuits as the SDC just laid out differently to fit the larger body mics. And in most cases they use the same capsules as the SDC but with a fake spacer around them so they appear bigger when you look through their grill.

As you can see it is not really a 34mm capsule. It’s the same 19mm capsule from the 603/604 KM84 clone.

Wow. So that went sideways. What was meant as a tutorial turned into a history lesson. Dang. Well let’s get back to business shall we. Let’s talk about how we can effortlessly and without soldering / grinding / filing upgrade the capsule. We’ve already have an article about how you can mod the housing of these SDC to get a better sound HERE. But here is a tutorial on how you can get better sound out of these clones without all the work and fancy tools 

Needs List:

  • Monoprice 600701 Omni Capsule ($20)
  • Transsound TSB-165A ($7)
  • Digital Calipers or Wrist Watch Wrench (Coupon it at Harbor Freight)


Unscrew the lockring all the way and set it aside for later. To do this you will want to use the backside of your digital calipers or use a wrist watch wrench.

This is a wrist watch wrench. It is used to open the battery door on the backside of a watch.

When you are done the contents of the 600701 capsule should fall out. You don’t need these parts ever again.


Seat the TSB-165A capsule into the 600701 housing so that it snuggly fits and covers the grill. It should feel like the two were always meant to be together if you placed it in correctly. If the TSB-165A sounds like a familiar capsule that is because it was made imfamous in micbuilders circles as the goto capsule for the “Alice Mic.”


Replace the the lockring and screw it on as tight as you can. You are now done. It should look a lot like this.

I have taken an extra step and added some solder to re-enforce the center pin on the TSB-165A. This is not necessary.

At first glance this looks like we swapped one Chinese capsule out for another Chinese capsule. Well yes. But here are the two frequency response charts. 

The Orginal Alctron Cardoid Capsule:

Very bouncy in its pickup and a huge boost in the highs which is the reason for the original capsule housing mod.
  • Transsound TSB-165A:
Less of a boost in the highs. Also notice there is less of a drop off in super highs. Also notice the -20db off axis rejection in the mids.

The new capsule will really utitilize the quiet Scheops circuit with it’s own signal to noise ratio of “greater than 66db.” The most notable difference was how much more sensitive the new capsule is. The original capsule was 39dB+/-2dB, the TSB-165A is 45dB+/-4 (it’s very possible the one I have swings more toward the +4dB sensitive.) 

Now a +/-4 variant is also a sign of poor manufacturing and QC. So my advice is to purchase a few capsule and test out which one sounds the best out of your batch. At $7 a capsule purchasing three isn’t exactly breaking the bank. Plus you can use the others for other builds!

I hope this was insightful. The T01A is a great mic to mod. And if you can purchase a pre-2013 mod you can mod the circuit more and upgrade the components to higher quality ones of the same values.


2 thoughts on “Tutorial: KM84 Clone Upgrade

  1. Quick question, since this is an electret capsule and doesn’t need the phantom power, did you have to perform any other mods to the circuit to get it work with it?


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