I recently purchased a BCL-LOOP Ver. 11, an amplifier for small magnetic loop antenna. This was developed by The Hokushin Electronic Service in Japan (Sorry their website is only in Japanese). The amplifier comes as assembled PCB, and I put into a small plastic enclosure.
Please note that the enclosure is not intended for outdoor use this time, and I wanted to compare its performance with other amplifiers, by using an identical indoor small loop element (triangular, 1 meter each side).
The following video is when I received Radio Nacional da Amazonia on 11780kHz and every 15 seconds I switched amplifiers: ∆-LOOP-X (developed by Mr. Kageyama, Japan. See also this page) → BCL-LOOP 11 → AAA-1B (developed by LZ1AQ, Bulgaria) → then back to ∆-LOOP-X. ∆-LOOP-X was in non-tunable mode.
To be honest, I did not feel significant differences between the amplifiers when I listened by ear, but on the spectrum, BCL-LOOP Ver. 11 showed lower noise floor than others.