AEA's R44 Series microphones all share the authentic sound, feel and look of the 1936-38 RCA 44BX. The R44 series microphones are all detailed, hand-crafted replicas, using parts that are made to be interchangeable with an original RCA 44. AEA manufactures three different versions of the R44 and an optional hotrod. At the core, every version of the R44 sounds the same when powered with a ribbon preamp. The major differences between the versions are the exterior look and the amount of output level. The passive R44 is available in two exteriors - the original museum-quality replica R44C and the aesthetically cost-effective R44CE. Both mics have an identical sound and are exactly the same on the inside. The difference between the two is only cosmetics and price. Active A440 upgrade has 18dB level increase and is optimised for all preamps Unparalleled warmth and legendary character Full and rich tonality with generous low end and proximity effect Faithful reproduction of the RCA R44BX. Ribbon material meets or exceeds original RCA spec. Made in the U.S.A.