Extending Recording Time of a Marantz PMD-661 Jeff April 2, 2014 All, Devices 3 Comments The Marantz PMD661 is one of the sound recorders of choice for professional ornithologists. However, the battery life using AAs is limited to about four hours, which isn’t enough for some applications. The Macaulay Library of Sound and Video at the Cornell Lab or Ornithology ran a test using our V44 USB Battery (12,000mAh) and the PMD661. According to the team at the Library, the PMD661 ran for 13.75 hours from the V39 (now the V44), “recording two channels of 48kHz/24-bit audio, from Sennheiser MKH20 and MKH30 mics (one each, which is our standard MS-stereo mic configuration) that the 661 phantom powered, while the 661 also nominally drove a set of Sony MDR-7506 headphones.” Note: Our optional 4.0×1.7mm Phone Adapter and USB cable is required to connect from the V44 to the PMD661. 3 Responses Karl Fitzke April 2, 2014 Might also someday rig up a dummy battery interface (wooden dowels in place of the AA batteries, wired up to a Voltaic battery) for the Roland R26 – another great value in field recorders. -Karl F. P.S. Thanks for your very responsive help on this task, Jeff. Reply David March 20, 2015 Hi, I have a PMD661 and can say for certain that it does not have the facility to charge its AA batteries from the external power socket. So there is absolutely no need to remove the batteries when running it from external power, be it an AC adaptor or a battery pack.. As far as I know, the Roland R26 is the same. Generally speaking, the vast majority of products that take AA batteries do not have charging circuits built in. Reply Voltaic Systems March 23, 2015 Hi Dave – post is updated to reflect this information. We’ve seen systems that will charge the AAs from the external power supply but were clearly wrong in this case. Reply Leave a Reply Cancel Reply Your email address will not be published.CommentName* Email* Website This site uses Akismet to reduce spam. Learn how your comment data is processed.