I have built 2 of these MK136 kits and they turn out real nice. I put one on 3 different parabolic dishes with all the correct mathematical figuration for placement of the mic. Which is the the focal length. On all 3 dishes I get the same sound from this kit that I get with the other one. I have tried baffles between the mics and tried splitting them and even side by side. Still the same thing. All I can hear outside is cars and trains and planes but I can hear really faint voices but cant make them out. I read an article that changing r1 from 1k to 20k can increase the voices and normal sounds. I guess by default you have a 10k resister in the kit. Can I change the r1 and r2 resisters to 20k resisters to help with hearing normal sounds? Also can you recommend a mic change to help me in my quest to build a really nice parabolic mic that will pick up voices from afar. I know it is possible because I built one along time ago but used a whisper 2000 as the mic and amp. Also is it possible to install a photo transistor (ambient light sensor) to use this unit with a laser to make a laser listening device. I am old and just playing with my days and always wanted to do this. I think your kits are pretty kool and I plan to purchase more of them. Thank y6u in advance for any help.