I added resistors.
There is no buzz at all anymore without rca connected or when connected to mobile phone, rca cables with nothing connected at the other end still act like an antenna. Buzz is the same when connected to tv.
I will try with different rca cables and new psu. Will build it tomorrow. Toslink adapter may solve the problem now... I'm waiting for it.
There is no buzz at all anymore without rca connected or when connected to mobile phone, rca cables with nothing connected at the other end still act like an antenna. Buzz is the same when connected to tv.
I will try with different rca cables and new psu. Will build it tomorrow. Toslink adapter may solve the problem now... I'm waiting for it.
2.2 ohm series .1 uf cap parallel output to ground trap RF interference. Every person carries a gigahz radio with them now, a cell phone. Business band, police, fire, cb radio are also problems. My diy amplifier picked up AM sports talk radio until I filtered the input jack with 150 pf to ground.
11 turns 12 ga wire wound around a 1 cm pencil (remove the pencil after winding) series the speaker also helps block RF coming in that way. That is parallel a 7 to 10 ohm 3 watt resistor. Of course a grounded steel case is fundamental to RF blockage. These accessories just block what gets in through the jacks & wires.
You can salvage the filter inductor in previous post from a dead flat screen TV, or a PCAT switcher power supply. they are chokes.
11 turns 12 ga wire wound around a 1 cm pencil (remove the pencil after winding) series the speaker also helps block RF coming in that way. That is parallel a 7 to 10 ohm 3 watt resistor. Of course a grounded steel case is fundamental to RF blockage. These accessories just block what gets in through the jacks & wires.
You can salvage the filter inductor in previous post from a dead flat screen TV, or a PCAT switcher power supply. they are chokes.
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I think that I have some windings salvaged from old car radios.
Will make psu with torodial now and add windings.
Will see how it goes, I think that it doesn`t pickup radios or anything like that because the sound of buzz is constant.
I will have to make metal cage around the amplifier for sure because I will install it into wooden box (soundbar) tv and tv box will sit on it.
Will make psu with torodial now and add windings.
Will see how it goes, I think that it doesn`t pickup radios or anything like that because the sound of buzz is constant.
I will have to make metal cage around the amplifier for sure because I will install it into wooden box (soundbar) tv and tv box will sit on it.
Part of the problem was cheap rca cable. I bought gold plated connectors and supreme shielded high quality cable and it's completely quiet with tv turned off. There is still a bit noise with tv turned on at low volume.
Now onto the power supply.
Now onto the power supply.
Ok, power supply is done.
All noise is gone, except when I plug it into tv. Where is still that buzz.
Signal gnd is from pin 12, grounded with 50ohm seristor.
There are 1k resistors on rca inputs...
There is no noise when I connect signal inputs via Toslink to analog converter.. But converter is to silent, when I connect diy single stage NE5532 preamp in between the buzz is there again, louder.
I should mention that I used this diy preamp with my zeck pt-7 amplfilier and pc with no noise at all.
Tryed to go analog from tv and used ground loop isolator. The buzz is louder again.
Any suggestions?
All noise is gone, except when I plug it into tv. Where is still that buzz.
Signal gnd is from pin 12, grounded with 50ohm seristor.
There are 1k resistors on rca inputs...
There is no noise when I connect signal inputs via Toslink to analog converter.. But converter is to silent, when I connect diy single stage NE5532 preamp in between the buzz is there again, louder.
I should mention that I used this diy preamp with my zeck pt-7 amplfilier and pc with no noise at all.
Tryed to go analog from tv and used ground loop isolator. The buzz is louder again.
Any suggestions?
Buzz is between 25hz and 45hz, most at 40hz with 6mV ripple. I get same pattern if I connect scope with or without amplifier. There is a slight hiss when button gets pressed on remote.
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I tried but it doesn`t buzz doesn`t change. I can hear pop in speaker if I turn light off, but buzz stays the same.
If I connect it to laptop with charger plugged in there is no buzz.
I managed to get toslink to analog converter with preamplifier buzz free, there is only some silent hissing. I could live with that. But I like sound with analog connection from tv better and when I change eq settings no tv it affects headphone jack out, but not toslink.
Check shield continuity on the RCA cables with an ohm meter.
And earthing in the house wiring,,, could be picking up stray RF signals.
And earthing in the house wiring,,, could be picking up stray RF signals.
And if you try another TV ?
If you get a "popping " noise when the light switch is activated then your input filtering isn't too good.
If you get a "popping " noise when the light switch is activated then your input filtering isn't too good.
Tell me please what should I add on primary i have nothing, on secondary I have diode bridge, followed by 2 10.000uF revervoir capacitors, followed by 0.1uF film capacitor, a choke in series with positive rail (scrapped from car stereo) followed by 0.1uF film capacitor.
Shield is good, I bought premium shielded cable an metal golden plated connectors. Measured resistance of ground from amp to tv jack and its 1ohm, measured from jack to other grounding points (hdmi, scart, antenna) to make sure there is good contact in the jack and it is 0 ohms.
Nor tv or amplifier are earthed. Didn`t earth the amp yet as I`m waiting for speaker box to make backplate for amp.
I tried one and it was much worse. Can`t tell if isolator was faulty tho, I borrowed one from friend.
I know they are gold once saved me on my diy android car stereo build, it removed loud digital noises (like ones from dial up modems).
Will order new one.
