如題，唔知點解決，請大家幫忙！！！
AV amp （denon avc-x6700h）前置pre-out 去 power amp 有好大電流聲，（試過換唔同既RCA，試過換唔同電源線，試過電源分開拖板插都唔得）
AV amp 前置pre-out 去 合併機 AV bypass 冇事，
合併機 pre-out 去 power amp 都冇事
所以AV amp 同 power amp都應該冇問題

Do you have any LED light turn on when you hear the hum noise? If yes, try to turn off all LED light.

多數是天線問題，你試下甩開天線，如果無左電流聲，去買個天線 Isolator 就可解決

地迴路引起hum 声，amplifier 駁 AV 好易有 hum 声，尤其駁左 TV, 好多時个訊号會帶电，引起 hum 声。

部AV amp 插 RCA 去 power amp，AV amp 冇著機，只係Standby mode 都已經聽到有好大電流聲，
部AV amp 係冇插到任何天線同HDMI，只有RCA 去 power amp

Try try :

https://post76.hk/thread-32725-1-1.html

AV amp 係冇插到任何天線 ---＞ 但你的天線looping是相通的, 所以甩開天線問題就可解決

但AV amp 前置pre-out 去 合併機 AV bypass 冇事，冇電流聲，點解呢？？？

You have ground loop problem between av amp & power amp.

mcc2018 －＞ You have ground loop problem between av amp & power amp.
可以點解決？

Check if your mains plug is grounded with the chassis, try disconnect as shown below. Make sure the source end is properly grounded for safety.

https://www.psaudio.com/ps_how/how-to-find-and-fix-hum/
情況好似咁
120Hz hum/buzz typical of ground loop problems.

你部AV amp 無接駁電親嗎？有，你試試移除電視天線睇睇

部AV amp 無接駁電視

#9

Dear mcc2018,

Where could we find those pictures and explanation (regarding ground loop)?

Thanks.

最後修改時間: 2021-01-13 13:14:15

#15, please ref below:
https://www.audiosciencereview.com/forum/index.php?threads/ground-loops-101.7162/

i had a similar problem. my av amp is denon 6500. eventually found that it was the tv antenna. the antenna cable was plugged into now tv box, which was plugged to denon. once i unplugged the antenna cable from now tv box, the noise was gone.

For TV/Radio antenna ground loop problem, the galvanic antenna isolator such as the one shown below is a must:

本應我設計嗰隻Signal Path Isolator（SPI）正正就係想解決師兄呢個問題，你呢個情況正好試試我嗰個設計可唔可行。以科研角度我真係好想借俾你試試，但這為非賣品，如果真係得嘅話咪盞搞。

其實真係關電視天線事？？ 電視都拎走左。。。
而家AV amp rca 去 power amp ，電制位插美式拖板，拖板插左AV amp 同 power amp