I have a Marantz 2226b that had developed a noticeable hum, but only on FM. 75 ohm amplified and 300 ohm wire produced same results. Aux and Tape settings produced no hum. So I pulled it from the living room setup and put in my basement dwelling Harmon Kardon Citation Eleven preamp, Pioneer TX-950 tuner, with Lepai 2020+ (used for testing) and no hum was present.
I opened the Marantz, and inspected the power caps, which looked in pristine shape (Elna, looked as if had been replaced already), and were showing no signs of bulging or leaking. I did a no nothing inspection of everything on the board, and saw nothing. So I put it back together and took to my basement setup. Plugged it in to a Monster power center, with no other interfere items near, and instead of using the internal amp, I plugged into a Dynaco Stereo 410. The hum was still present.
I was ready to throw in the towel, and then decided to see if the hum interfered with the AM band. It was not, but noticing that a few stations almost came in, I extended the AM antenna. When I switched back to the FM, the hum was gone. Now I don't know what I did to finally stop the hum. What it the switching to AM? The Antenna? I've moved the antenna all around and no hum. It doesn't make sense to me, but I hope someone out there can explain. I want to get this receiver back in my living room, but don't want to without understanding this problem.
I opened the Marantz, and inspected the power caps, which looked in pristine shape (Elna, looked as if had been replaced already), and were showing no signs of bulging or leaking. I did a no nothing inspection of everything on the board, and saw nothing. So I put it back together and took to my basement setup. Plugged it in to a Monster power center, with no other interfere items near, and instead of using the internal amp, I plugged into a Dynaco Stereo 410. The hum was still present.
I was ready to throw in the towel, and then decided to see if the hum interfered with the AM band. It was not, but noticing that a few stations almost came in, I extended the AM antenna. When I switched back to the FM, the hum was gone. Now I don't know what I did to finally stop the hum. What it the switching to AM? The Antenna? I've moved the antenna all around and no hum. It doesn't make sense to me, but I hope someone out there can explain. I want to get this receiver back in my living room, but don't want to without understanding this problem.