From Cathedral Pipes, the Durham Micro Amp Buffer, designed to add up to an additional 25db of clean, transparent gain for all passive microphones. It uses typical 48v Phantom Power - found on most mic preamps - to add more db to low-output passive mics, which often require ramped-up gain levels to work at their optimum, and that many lower end preamps don't usually have available. An example of a passive low output mic that would benefit from this would be the Shure SM7B, which is a great sounding dynamic mic, but is inherently low in output, as well as many Ribbon mics, which also require a significant amount of gain - that most cheaper preamps usually don't have enough of. This appears to be similar to the Cloudlifter, except that at $65.00 (U.S), it's much cheaper ( the Cloudlifter retails at $149.00) From CP: The simple "XMB" technology used inside is the same circuit found within our new Ribbon microphones. It is found to both improve SNR for all passive microphones and provide a fixed impedance to the Ribbon Mics. Features Uses 48V phantom power found on most preamps. 2 LSK389 J-Fet matched pairs. Works on all Passive Microphones Ideal impedance loading for optimal performance @3Kohms Rugged and very compact. Made entirely in the USA. MSRP for The Durham Micro Amp is $65.00 ( U.S.) http://www.cathedralpipes.com/zen-cart/index.php?main_page=product_info&cPath=68&products_id=208 FWIW -d.