Need some help? Give us a call: toll-free phone
or email:
Jensen Transformers Logo

Jensen Transformers JT-MB-CA 1:1 Microphone Input Transformer

for Ultra-low Noise Amplifiers

Made in the USA
Jensen Transformers JT-MB-CA 1:1 Microphone Input Transformer

Jensen Transformers JT-MB-CA 1:1 Microphone Input Transformer

The Jensen Transformers JT-MB-CA 1:1 Microphone Input Transformer features a dual Faraday shield for very high CMMR of 122 dB at 60 Hz, as well as a 30 dB magnetic shield.  The wire leads and included angle bracket mounting hardware make it perfect for DIY projects.  Also available in a PCB mounting style (cart option below).

Like all Jensen microphone input transformers, the JT-MB-CA offers legendary sonic transparency. Internal Faraday shielding virtually eliminates hum, buzz, and RF interference, while MuMETAL® magnetic shielding cans reduce hum caused by nearby magnetic fields. Optimized noise performance is ensured by matching the step-up turns ratio to you input stage design.  Extended low-frequency and Bessel-tailored high-frequency response results in the ultra-low time-domain distortion (DLP) that only Jensen offers. Insertion loss is minimal and adding phantom power is simple.

Here are some specs:

  • Impedance ratio:  150:150
  • Turns ratio: 1:1
  • Maximum 20 Hz input: +2dBu
  • THD @ 20 Hz: 0.045 %
  • 20 Hz re:1 kHz: -0.10 dB
  • 20 kHz re:1 kHz: -0.04 dB

This transformer is also available in a PCB mounting style as JT-MB-CPCA.

With inferior products coming from all over the world, we think it is a genuine treasure to find a company like Jensen Transformers, actually designing and manufacturing some of the finest products in the world, right here in the USA, and we are proud to be able to offer their products. The JT-MB-CA is made in the USA, is backed by the manufacturer's comprehensive one-year warranty, and has a remarkable 20-year warranty on the transformer device itself.

Jensen Transformers' Description

Jensen Transformers JT-MB-CA
 Microphone Input Transformer


  • Ideal retrofit to solve problems with transformerless preamps
  • Dual Faraday shields provide very high CMRR: 122 dB at 60 Hz
  • Eliminates complex circuitry required to block 'phantom' power
  • Excellent frequency response and time domain performance
  • Low transformer related Noise Figure

This transformer is designed to couple a nominal 150 Ω mic to the 3 kS input impedance typical of 'transformerless' preamps. Both windings are fully balanced and either may be reversed to invert polarity. A 30 dB magnetic shield package is standard. Not recommended for mic 'splitter' applications (use JT-MB-C).

Jensen Transformers JT-MB-CA, wire leads

Here is a good look at the wire leads.

Jensen Transformers JT-MB-CA, mounting hardware

This shows how the included angle bracket mounting hardware works.

Jensen Transformers JT-MB-CA Specs - click to download PDF

Here is the JT-MB-CA spec sheet.  PDF format.

Purchase Information
Product Description SKU MSRP Your Price Quantity
1:1 Microphone Input Transformer with Wire Leads (as shown, stocking item) JT-MB-CA $119.99 $99.99
1:1 Microphone Input Transformer with PC Board Mount (not shown, special order item) JT-MB-CPCA $107.99 $89.99
SSL Secure Site Logo
Jensen Transformers Authorized Reseller Seal

Why Cable Solutions?

Design excellence, high quality materials, meticulous workmanship, and superior service...put it all together and you get a superior product. Don't get stuck with bad advice, poor service, slow shipment or an inferior product. If you want the best, here it is.