Sean de Silva
Well-Known Member
A couple of days after cyclone tauktae had wreaked havoc in Mumbai, I switched on the system only to hear a weird disturbance on the 3050i that I’ve never heard before. I usually switch on the power amp followed by pre amp. With only the power amp turned on there was no hum. As soon as the pre amp was turned on the disturbance appeared on both speakers. Sources not turned on. Turning up the volume dial did not increase the amplitude of the disturbance so that was a relief. Trying to figure out what this could be I then realized I was hearing the ac supply 50Hz hum! Exactly the same sound as this yt vid
My first assumption was this hum has something to do with Mr Murthy’s power cables and/or the Mogami ICs shielding/soldering. So I immediately got in touch with him and he asked if power cords and ICs were in close proximity of or touching each other which is the case. He then advised troubleshooting steps to pinpoint the source of this annoying hum. Last evening I switched on power amp followed by pre amp and lo and behold the hum on the speakers has mysteriously and miraculously disappeared! All that I hear when I press my ear to both tweeters is a very soft hiss which has always been there. When I told Mr Murthy what had just happened and that I didn’t fiddle around with or swap any cable he congratulated me on the disappearance and said that this hum could have been due to faulty ac supply. It goes without saying that if this reoccurs I will have to swap power cords and ICs as he has advised.
Hence the perplexity.. has anyone experienced something like this happen in your system where this ac hum suddenly appears and disappears?
My first assumption was this hum has something to do with Mr Murthy’s power cables and/or the Mogami ICs shielding/soldering. So I immediately got in touch with him and he asked if power cords and ICs were in close proximity of or touching each other which is the case. He then advised troubleshooting steps to pinpoint the source of this annoying hum. Last evening I switched on power amp followed by pre amp and lo and behold the hum on the speakers has mysteriously and miraculously disappeared! All that I hear when I press my ear to both tweeters is a very soft hiss which has always been there. When I told Mr Murthy what had just happened and that I didn’t fiddle around with or swap any cable he congratulated me on the disappearance and said that this hum could have been due to faulty ac supply. It goes without saying that if this reoccurs I will have to swap power cords and ICs as he has advised.
Hence the perplexity.. has anyone experienced something like this happen in your system where this ac hum suddenly appears and disappears?