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Our Transformers



LMI143 (14K(7K:7K):(200R:100R)300R), which features a medium-sized core, compatible with 251, C12, C800G and the 87 circuit. Electronically compatible with solid state and tube microphone preamps wired in reverse as an input transformer or as an output transformer for dc coupled tube preamps.

Inspired by the legend of the V2148 transformer found in the early 251 microphones, which was a larger core and lower turns ratio (8:1) than a T14/1 (12:1). The LMI143 can be wired to offer the 8:1 ratio or the 12:1 ratio, among many others. 

Due to its larger core size, this transformer is a superior choice for its increased headroom and bass response especially in 12AT7/6072 plate follower circuits. It is equally at home in modifying microphones inspired by 800G circuits. 



LMI8 is a large core transformer that features a split bobbin platform presenting 8.5K(4.25K:4.25K):300R(200R:100R). This transformer is a heavy, large and gorgeous sounding offering that is perfectly suited for the U47 microphone. Wired as a 8.5K:200R transformer it presents a 6.5:1 ratio using large laminations featuring a special brew of metallurgy and winding techniques that present excellent signal handling quality, intense musicality and lush tonal character. Due to the platform utilized for this design, the amount of laminations available are larger than a typical microphone output transformer (nearly ¾” or 17.8mm of actual laminations) and give the end user the advantage of higher signal handling quality and advantageous low frequency response that does not sound artificial. This transformer is recommended for microphones with larger bodies such as U47 style bodies, the GT2B and the SYT5. As standard, this design features split primaries and secondaries, which makes it compatible with other designs such as FET microphone circuits, tube microphones using cathode follower circuits, microphone preamps (solid state and DC coupled tube). Possible alternative ratios include 3.76:1 (4.25K:300R), 4.6:1 (4.25K:200R), 6.5:1 (4.25K:100R), 9.2:1 (8.5K:100R), 5.3:1 (8.5K:300R).



LMI 50600 transformer can function as both the input and output transformers for the infamous LA2A. These transformers feature 4 windings on both primary and secondary offering the user numerous combinations of input and output impedances for various applications. These transformers are of a larger core type and present an advantageous degree of signal handling, frequency and transient response, along with a flexible platform for multiple use cases. Wired as a 600R:50K the turns ratio is 1:9 or for those seeking a closer turns ratio to the LA2A A10 transformer, 3 windings can be utilized on the primary for 450R:50K presenting a 1:10 ratio. Functioning as the output transformer for the LA2A, one simply can reverse the LMI50K:600R and wire the transformer as a 12.5K:600 presenting a 5:1 ratio similar to the LA2A A24. Also a perfect fit for those seeking to recreate infamous Motor City DI box.

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LMI - Designs

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