Our low losses, low distortion, and extremely low DCR ribbon microphone transformers are wound on annealed Amorphous tape wound cores. The typical primary DCR is only 0.002 Ohm and secondary DCR between 3 and 10 Ohm, depending on ratio.
In addition to our main line, for a small fee we can customize and match our transformers to ANY ribbon with impedance, inductance, damping, turn ratio, frequency response, and noise.
We have two sizes of the transformer: large (ø 1.100” x 0.800” tall), and smaller (ø 0.850” x 1.100” tall to fit smaller barrels of some of the Chinese ribbon microphones). There is no noticeable sonic difference between those two, except for slightly lower SPL handling of the smaller version (but here we are talking about numbers no sane music source can deliver, anyway). If the space is of issue (for example, for use in Beyerdynamic M130, M160, M260, or M500 microphones, or some DIY projects) we can also make the smaller transformer un-potted, with ø 0.750” x 0.430” size.
Please note, in addition, each size of our transformers has two versions. First version has flat frequency response and does not have a letter designation. Second version is with bass roll off for close miking to compensate for proximity effect, usually associated with ribbon microphones. This version has designation ‘B’.
Our transformers are impregnated in metal cans.
- RT28 1:28 Ratio —$129 (suits RCA Varacoustic, 77, Beyer M130, M500, M260, M360,
and other mics with narrow ribbons re-ribboned with 1.8 micron foil)
- RT32 1:32 Ratio —$129 (suits Beyer M160, Apex 205/210, Nady RSM1, 2, and
other similar Chinese microphones, re-ribboned with 1.8 micron foil)
- RT36 1:36 Ratio —$129 (suits Nady RSM4, Stellar RM3, and other
Chinese microphones with similar motors, re-ribboned with 1.8 micron foil)
- RT40 1:40 Ratio —$129 (suits Beyer double ribbon microphones, and any of above, if
additional damping needed)
- RT55 1:55 Ratio —$139 (for use with ribbons of thicker foil, or if additional
- RT70 1:70 Ratio —$149 (for use with active ribbon microphones, or ribbons of
thicker foil, or if additional damping needed)
- RT100 1:100 Ratio —$159 (for use with active ribbon microphones)
- RT200 1:200 Ratio —$179 (for use with active ribbon microphones)
We also make transformers for using with 0.6um foil leaf, as well as 30 Ohm—200 Ohm transformers (to suit Coles 4038, Reslo, Melodium, and other 30 Ohm ribbon mics)-- custom order.