Littman Stethoscope

My husband is debating about who should get a stethoscope he 'the doctor of SA that gets ready to take his steps in two weeks (which specifically expect to hear even the most minuscule murmur) and needs better quality stethoscope that can be obtained. Of course, already has a stethoscope (a basic model of Sprague), which is OK but not great. He doesn 't feel at all better from my If Littman II and isn' t impressed with Littman cardiology matrix (which is what most of his colleagues use). Gradica the Littman 3000, mainly because it can increase the volume and focus on sound, but the problem is that of Proctor to make it through the electronic stethoscopes a bit difficult. Suggestions? The cost is not really an option (well, unless more than around $ 500), because we want the best quality. Any advice would be welcome. Apparently, should be able to hear the diastolic murmurs of grade II, such as ms and AR thin and differential MR., VSD, HOCM and TR.