Cheap Microphones, Premium Sound: DIY Upgrades

If a 16-cent capacitor can make a cheap podcast microphone sound like a $3,600 unit.... we had to know what other hacks there were to get premium sound from microphones selling for under $100.

So down the rabbit hole we went, solder gun at the ready. If you're handy, there are a number of mods that can make a cheap mic sound great.

It's either a shout-out or a shaken fist to Chris Person at Aftermath for leading us down this road by modifying a $40, used AKG Perception P220 (retail $159) with a simple under-a-dollar capacitor swap. In testing, it mimicked the $3,595 Neumann U87Ai almost perfectly.

Modifying budget microphones by upgrading components such as capsules, transformers, tubes, and circuit boards can greatly increase the capabilities of a budget podcast microphone. And as we discovered, there are a number of popular swaps out there. Several types of mods are detailed below, with specific steps for each at the bottom of this article.

Capsule Swaps for Enhanced Sensitivity and Clarity

The Behringer C-1, a large-diaphragm condenser microphone, is a common choice for modifications due to its affordability and robust build. One popular upgrade involves replacing the stock capsule with an RK-47 or RK-12 capsule, available from Microphone-Parts or Advanced Audio.

These capsules are designed to emulate the warmth and clarity of premium microphones like the Neumann U47. To perform the modification, the microphone body is disassembled, and the original capsule is desoldered and replaced, ensuring correct polarity alignment.

Another widely used model, the MXL 990, benefits significantly from a capsule swap. The K47-style capsule from Microphone-Parts is a favored choice, offering a more balanced sound with enhanced low-end response.

The modification involves removing the original capsule and mounting the K47, taking care to securely fasten the new capsule to minimize vibration and noise.

Circuit board upgrades can greatly enhance the audio quality of budget microphones by reducing noise and improving frequency response.

The Nady TCM 1050, a tube condenser microphone, often undergoes capacitor and resistor upgrades. Panasonic or Nichicon low ESR capacitors and metal film resistors are ideal replacements. These components reduce distortion and improve the signal-to-noise ratio.

After removing the stock components with a soldering station, the upgraded parts are installed, and the circuit board is tested for improved clarity.

Similarly, the Rode NT1-A, known for its extremely low self-noise, can experience a reduction in high-frequency harshness with WIMA film capacitor replacements. The circuit board is removed from the microphone body, and specific capacitors are swapped out based on schematic recommendations. These changes result in smoother high frequencies and a more natural sound profile.

Transformer Replacements for Improved Tonal Character

Replacing a microphone’s transformer can dramatically alter its tonal characteristics, adding depth and warmth.

The Shure SM57 and SM58, iconic dynamic microphones, are often modified by upgrading or removing their transformers. High-quality replacements such as the Lundahl LL2912 or Cinemag CM-2503 provide a flatter frequency response, which is particularly useful for studio recordings.

To perform the modification, the microphone is disassembled, the stock transformer is desoldered, and the replacement is wired in, ensuring the input and output terminals are correctly aligned.

The MXL V67G, another popular condenser microphone, benefits from replacing its stock transformer with a Cinemag CM-2480.

This upgrade refines the low-end and high frequencies, making the microphone more versatile for vocal and instrument recordings. The process involves carefully removing the original transformer and soldering in the Cinemag unit, which must be secured to prevent movement.

Tube and Component Upgrades in Tube Microphones

Tube microphones can achieve a richer, more vintage sound with upgraded tubes and capacitors.

The Apex 460, a tube condenser microphone, is frequently modified by replacing the stock tube with a Telefunken EF86 or a Mullard equivalent. These NOS (new old stock) tubes are known for their smooth response and warm tonal characteristics.

Additionally, capacitors such as Solen or Mundorf film capacitors are installed to improve signal flow and clarity. The process involves opening the microphone body, swapping out the tube, and upgrading capacitors on the circuit board.

The Alctron T-11A, another tube microphone, benefits from a similar modification. Replacing the stock tube with a JJ Electronics ECC83 tube enhances warmth and reduces noise. Nichicon or Panasonic capacitors are also installed to refine the audio quality further. These upgrades transform the T-11A into a professional-grade tool for studio use.

DIY Microphone Kits for Complete Customization

For enthusiasts seeking a hands-on approach, DIY microphone kits offer an opportunity to build a custom microphone with premium components.

Companies like Microphone-Parts provide kits for creating microphones such as the T-12 or S-87, which rival industry-leading models like the Neumann U87. These kits typically include RK-12 or CK-12 capsules, Cinemag or Jensen transformers, and WIMA film capacitors. Assembly involves soldering components onto a printed circuit board, mounting the capsule, and assembling the housing.

DIY builds, often used to create clones of the Neumann U87 or AKG C12, offer similar customization options.

Using components like Dany Bouchard capsules and Sowter transformers, users can replicate the tonal characteristics of these legendary microphones. Following detailed schematics, each stage of the build is tested to ensure optimal performance, and adjustments can be made to polar patterns or biasing for further fine-tuning.

By implementing these modifications, podcasters and audio professionals can unlock the full potential of budget microphones, achieving sound quality that rivals far more expensive models. Each modification requires varying levels of technical skill, but with the right tools and parts, even entry-level microphones can be transformed into professional-grade recording devices.

Here’s an expanded guide to the technical details, steps for the modifications, and specifics about the makes, models, and parts used for each microphone modification.

Capsule Swaps for Enhanced Sensitivity and Clarity

Behringer C-1

Make/Model: Behringer C-1, a budget large-diaphragm condenser microphone.

Modification: Replace the stock capsule with a high-quality large-diaphragm capsule.

Parts:

Suggested Capsule: RK-47 or RK-12 capsule from Microphone-Parts or Advanced Audio.
Tools Needed: Soldering iron, screwdriver, desoldering pump, multimeter.

Steps:

Open the microphone casing by unscrewing the body.
Desolder the existing capsule carefully, noting the polarities.
Solder the new RK-47 or RK-12 capsule into place, ensuring correct wiring.
Test the microphone for signal quality before reassembling.

MXL 990

Make/Model: MXL 990, a popular entry-level condenser microphone.

Modification: Replace the stock capsule with a K47-style capsule.

Parts:

Suggested Capsule: K47 capsule from Microphone-Parts.

Steps:

Open the microphone housing and locate the capsule mount.
Remove the stock capsule, noting the wiring configuration.
Install the K47 capsule, matching the original polarities.
Ensure the capsule is securely mounted to prevent vibration or noise.

Nady TCM 1050

Make/Model: Nady TCM 1050, a tube condenser microphone.

Modification: Upgrade capacitors and resistors to improve signal clarity.

Parts:

Capacitors: Panasonic or Nichicon low ESR capacitors.
Resistors: Metal film resistors for noise reduction.
Tools Needed: Soldering station, oscilloscope (optional for testing).

Steps:

Open the microphone and locate the circuit board.
Identify stock capacitors and resistors to be replaced (consult schematic).
Desolder and remove old components.
Solder the upgraded capacitors and resistors in place.
Test the microphone's frequency response with an audio interface or analyzer.

Rode NT1-A

Make/Model: Rode NT1-A, known for its low noise floor.

Modification: Replace capacitors in the circuit to reduce high-frequency harshness.

Parts:

Capacitors: WIMA film capacitors.

Steps:

Open the body and remove the circuit board.
Replace specified capacitors (consult DIY forums or schematics for exact positions).
Test and confirm reduced high-frequency peaks before reassembling.

Transformer Replacements for Improved Tonal Character

Shure SM57/SM58

Make/Model: Shure SM57 and SM58, dynamic workhorse microphones.

Modification: Remove or upgrade the transformer.

Parts:

Transformers: Lundahl LL2912 or Cinemag CM-2503.

Steps:

Disassemble the microphone to access the transformer.
Desolder and remove the stock transformer.
Install the new Lundahl or Cinemag transformer, aligning the input/output terminals.
If removing the transformer entirely, rewire the signal path directly.

MXL V67G

Make/Model: MXL V67G, a widely-used budget condenser microphone.

Modification: Replace the transformer for smoother low-end response.

Parts:

Suggested Transformer: Cinemag CM-2480.

Steps:

Open the microphone and locate the stock transformer.
Desolder and carefully remove the transformer.
Install the Cinemag transformer, ensuring proper orientation of leads.
Secure the transformer to prevent movement during use.

Tube and Component Upgrades in Tube Microphones

Apex 460

Make/Model: Apex 460, a tube condenser microphone.

Modification: Replace the stock tube and upgrade capacitors.

Parts:

Tube: NOS Telefunken EF86 or Mullard equivalent.
Capacitors: Solen or Mundorf film capacitors.

Steps:

Unscrew the housing and carefully remove the stock tube.
Insert the new Telefunken EF86 tube, ensuring proper alignment.
Replace capacitors on the circuit board for improved signal flow.
Test the microphone and check for any audible distortion or noise.

Alctron T-11A

Make/Model: Alctron T-11A, a low-cost tube microphone.

Modification: Replace the tube and key capacitors.

Parts:

Tube: JJ Electronics ECC83.
Capacitors: Nichicon or Panasonic capacitors.

Steps:

Open the microphone and remove the stock tube.
Replace with a JJ Electronics ECC83 tube.
Upgrade capacitors, ensuring proper orientation and soldering.
Reassemble and test the improved microphone.

DIY Microphone Kits for Complete Customization

Microphone-Parts Kits

Make/Model: Custom kits for microphones like the T-12 or S-87.

Modification: Assemble a microphone from scratch with premium components.

Parts:

Capsules: RK-12 or CK-12.
Transformers: Cinemag or Jensen.
Capacitors: WIMA film capacitors.

Steps:

Follow the detailed instructions provided in the kit.
Solder components onto the PCB, including capacitors, resistors, and the capsule.
Mount the capsule and assemble the microphone housing.
Test the completed microphone and fine-tune as needed.