TL3 Circuit Kit

$ 199.00

The TL3 is our next-generation implementation of the transformerless design pioneered by Schoeps. Once built, it will deliver performance specifications as good as almost any commercial microphone on the market, and better than most.

We designed this circuit kit to fit our new S3 microphone kits. But it also fits two inexpensive "donor" microphones:

  • MXL 770
  • Monoprice 600800

The TL3 differs from our existing transformerless circuit kits in three significant ways:

  1. It has 3 polar patterns
  2. It has 2 external switches
  3. The high-frequency EQ can be easily adjusted without soldering

Features & Benefits

  • High sensitivity, low noise, low distortion, ultra-pristine signal path
  • Three-way pattern switch: Omni, Cardioid, Figure-8
  • Switchable -10dB pad
  • Includes pre-biased NOS JFET for maximum headroom
  • User-adjustable high-frequency EQ allows easy voicing
  • Long-life C&K switches

Choose Any Capsule

The circuit works beautifully with all of our large-diaphragm capsules. Because the in-circuit EQ is easily adjustable, you can fine-tune the mic's high-frequency response without soldering. Just swap one socketed component to change the circuit's frequency response.

Included with this Circuit kit

  • Two-piece "TL3" PCB set, designed and manufactured in the US
  • 100% of components needed to complete the circuit, including 1% tolerance, low-noise resistors, pre-biased NOS JFET, and polyproyplene signal capacitors
  • Full-color, step-by-step installation guide (often described by customers as "the best DIY audio project manual on the market")
  • Tech support via email


These circuit boards will fit the MXL 770 and Monoprice 600800. They will not fit the MXL 990, nor the 990S, nor any other microphone.

Why did we choose the 770 and 600800 as the donor mics for this circuit kit? Because both models have two external switches. The original mic provides a pad and a high-pass filter. We retain the pad, but repurpose the HPF switch as a 3-way pattern switch (Omni/Cardioid/Fig8). (You will want to mark the new pattern switch positions on the body: from left to right the order is Omni, Cardioid, Fig8.)

Skill Level

This is an intermediate level kit, similar to our other transformerless circuit kits. It is harder to build than the T-84, but easier than the Fox 460 tube kit.

If you have built one of our microphone kits before, you should have no problems with this one. If you have never built a microphone before, we recommend starting with something easier, such as a capsule upgrade, or the C1/C3 circuit mod kits.

See a full listing of our DIY microphone kits, ordered by difficulty, in the FAQ.

If you have never soldered before, please do not purchase this kit. You must be able to reliably form sound solder joints, or you'll be wasting your time and money.

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