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C12 Microphone Kit Complete


This complete kit provides all of the parts required to build our C12 or ELA M251 clone microphones. We offer this kit in 2 grades. Budget and Premium. Complete documentation and project support can be found on our official build and support thread at

Important Change: Due to a change in volume purchase policies at AMI, we have transitioned all of our kits (premium and budget variants) to Cinemag CM-13114 transformer and will no longer be able to stock AMI products after our current stock is depleted. AMI T14 transformers are still being produced and available directly through AMI. We are happy to refund the cost of the transformer for customers who prefer to source the transformer independently.

All items with the exception of NOS 6072A tubes are available separately with no cost penalties in the webstore so build components can be completely customized. The "complete kit" option is simply an easy method to purchase all of the required components in one click.

Budget Kit includes:

- Alctron HT-11A donor body and power supply
- C12 pcb set
- Electronic Parts Kit
- Chinese 6 micron K67 based edge terminated capsule
- New Old Stock premium grade, fully-tested Mullard 12AT7 tube
- Cinemag 13114 output transformer
- Silver Teflon Hookup Wire
- 30 ft. Chinese 7 pin XLR cable

Premium Kit includes:

- Altron HT-11A donor body and power supply
- C12 pcb set
- Electronic Parts Kit
- Eric Heiserman backplate-correct HK12 capsule Handmade in USA
- New Old Stock GE 6072A microphone grade tube
- Cinemag CM-31334 transformer
- 25ft. Gotham GAC7 Swiss tube microphone cable
- Neutrik gold 7 pin connectors
- Silver Teflon hookup wire


- The complete step-by-step build documentation for the ELA M251 kit has not been completed yet. The ELA M251 project based on our C12 pcb set retains the C12's 9 pattern polarizing scheme which is different than the original body-switched 3 pattern configuration of the Ela M251.

- The NOS GE6072A tubes provided in our premium kits are mid-70's era military production tubes identical in construction to the five star tubes. They are fully tested to rigorous standards for tone, noise, microphonics, and are burned in for 48 hours to ensure stability. These specific tubes test "microphone grade" on one triode only as the C12 and ELA M251 circuits only utilize one triode of the tube. You will need to configure your kit to either utilize "side 1" or "side 2" of the tube as appropriate.

- In order to alleviate the impact of our kits on the dwindling supply of New Old Stock GE6072A tubes, we are supplying budget kits with the NOS Mullard 12AT7 tube. We feel the tonal response of this more commonly available alternate tube is still superior to the new production 6072A tubes on the market. It is our strong belief and recommendation that genuine GE6072A tubes should be reserved for premium builds that utilize the much more costly backplate-correct capsules. Eric Heiserman, Tim Campbell, and Beesneez are the currently known suppliers of these reproduction capsules that remain true to the original chambered backplate design. If the original 6072A configuration must be retained in a budget build, we recommend the Electro Harmonix 6072A tube which we hope to stock in fully tested samples in the future.

-The per unit cost for 2 premium complete kits is higher because we utilize tubes that test clean on both triodes. We advocate pair builds to utilize opposite triodes between the 2 microphones so tube life can be doubled by simply swapping tubes between the 2 microphones periodically.

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