Jensen Moving Coil transformers offer outstanding performance for the demanding audiophile. The combination of low distortion, wide bandwidth and superior common-mode rejection make these transformers an ideal choice for moving coil applications. How to Select the Right Moving Coil Transformer Due to the large number of moving coil cartridges available (with an amazing variety of impedances and output levels), and the number of Jensen Moving Coil transformers available to choose from, we have compiled a spreadsheet showing all of the combinations of cartridges and transformers. If your cartridge is not represented in the table, please contact Jensen Transformers for assistance in selecting the proper transformer. Please notify us if you believe that any of the information is incorrect, as we would like to correct any erroneous information as soon as possible. Moving Coil Cartridge/Transformer Table (Zipped - Microsoft Excel Format) JT-347-AXT Damping Value Charts (122kB PDF) General Selection Guidelines For flexible interfacing to standard 47k Ohm RIAA phono amplifiers, the JT-347-AXT would be the premium choice. This large geometry core transformer features multiple primary windings, which may be strapped in parallel, series-parallel or series to accommodate a wide variety of cartridges. This would be advantageous for users who frequently change the type of cartridge used. Our JT-34K-DX provides 31dB of gain (the highest step-up ratio that we offer) for very low impedance, very low output cartridges. This transformer would be an excellent choice for 100uV - 150uV cartridges. Our JT-44K-DX offers a very high-performance, yet cost effective alternative to the JT-347-AXT for RIAA preamp interfaces. Although it does not have multiple primary windings, it can be used with cartridges spanning a wide range of impedances and output levels. It has a higher noise figure than the JT-347-AXT, and somewhat higher distortion, but offers better high frequency bandwidth (at the expense of some low frequency performance). Finally, for users with very low noise, high-gain phono amplifiers, we offer the JT-346-AXT. This moving coil transformer has step-up ratios one-half of those of the JT-347-AXT, but has twice the high frequency bandwidth. It is intended for use with very, very low noise vacuum tube preamplifiers (6DJ8 tubes or similar) or with low noise solid state circuits using 1nV/rtHz op-amps (like the JT-990 or AD797) or discrete bipolar or FET transistor designs.