A840 Ribbon Mic Review / Tape Op
"AEA makes some of the world's finest ribbons mics, including their recreation of the RCA 44-BX (the AEA R44) and their groundbreaking active A440, which carry hefty price tags. Wes Dooley, the founder of AEA, wanted to create affordable alternatives for us "married guys" who have obligations that sometimes take precedence over our gear lust. Enter the A840, which shares the trademarked Big Ribbon design with its elite ancestors, and the lighter and more open body design of the passive AEA R84 [Tape Op #38]. As an active mic, the A840 contains a JFET line- driver/buffer that does not provide any gain, but allows the mic to work well with long cables and virtually all mic preamp impedances. Additionally, the A840 contains a high-ratio Lundahl transformer, which provides a significant amount of gain so that the mic produces a signal level that equals that of most studio condensers."
A840 Ribbon Mic Review / Sound on Sound
"American manufacturers AEA have been working with high-performance ribbon microphones for over 30 years, and one of their more popular models is the 'large ribbon geometry' R84, which I reviewed back in the February 2004 edition of Sound On Sound (/sos/feb04/articles/aear84.htm). Like most ribbons, the R84 has a low-ish output level of 2mV/Pa, which can prove challenging for a lot of preamps, but AEA have addressed this in the A840 model — basically an R84 with a built-in, phantom-powered JFET gain stage. Consequently, the output level is a more easily accommodated 6.3mV/Pa, which is a good 10dB louder than the R84."
A840 Ribbon Mic Review / Recording Mag
"The A840 is promoted to be an R84 with added phantom powered electronics, but to my ears it sounded better than that; I did not hear much of the midrange issues that I heard with the R84. The added phantom-powered electronics do what they are supposed to do and they don't get in the way, and the resulting mic has a very good and usable sound."