exclusive Posted March 21, 2018 Posted March 21, 2018 Dear all, Recently I found out that my power amp is having serious ground leak. I discovered this when I touch the casing and got shock. I tried connected a ground cable from its casing to the Phono ground of my avr. I can see sparks when I connect to the Phono ground. when I connect them, it sends a signal back to the power amp and turn it on. because of this issue, I can hear high pitch noise from the speakers. after I ground it, the noise has reduced significantly. what causes this ground leak issue? is it consider serious? Sent from my SM-N950F using Tapatalk
Boxerfan88 Posted March 21, 2018 Posted March 21, 2018 Take safety precautions. If you can, measure the ground voltage (amp ground vs. socket ground). Then disconnect all interconnect cables from amp (except power), measure again. If the voltage drops to zero, it’s coming from somewhere else. If it stays high, it’s coming from your amp. I’m surprised the amp casing is not grounded - safety issue. Sent from my iPhone using Tapatalk
Esquire Posted March 21, 2018 Posted March 21, 2018 All power amp must be grounded. If there are leakage the RCD will strip.
jeromelang Posted March 21, 2018 Posted March 21, 2018 My 200 watts sony power amp not grounded. I added ground wire internally between iec ground terminal and chassis. Once that is done, sound quality audibly improved. But take note: cable directionality is super important - even for grounding purpose!!!
exclusive Posted March 23, 2018 Author Posted March 23, 2018 My 200 watts sony power amp not grounded. I added ground wire internally between iec ground terminal and chassis. Once that is done, sound quality audibly improved. But take note: cable directionality is super important - even for grounding purpose!!! I opened up and checked that it is grounded to the casing from the iec ground. Sent from my SM-N950F using Tapatalk
Boxerfan88 Posted March 23, 2018 Posted March 23, 2018 Oh wow, if IEC ground is connected to casing; whatever casing current should have flowed to ground and potentially tripped the ELCB. Yet it did not, and you reported getting a shock before. It looks like you may have a bigger problem, the IEC ground isnt working. It’s dangerous. Sent from my iPhone using Tapatalk
Esquire Posted March 23, 2018 Posted March 23, 2018 When IEC has a wire connected to casing, the appliance has to be grounded at the the 13A socket.
Casper adrian Posted April 1, 2018 Posted April 1, 2018 My Rotel power amp came back after repair with also loud high pitch sound, could u recommend any repair shop? Thank you
exclusive Posted May 3, 2018 Author Posted May 3, 2018 I have tried grounding using RCA TO UK 3pin. it works. much better now. Sent from my SM-N950F using Tapatalk
econav Posted May 3, 2018 Posted May 3, 2018 In the first place , why there are leak ? where they come from and where they should go ? casing does not leak , but the unbalance of the output the power supply filtering circuit cause that acccess and this comomly from the pcb connected to the casing and from that same point connected to the main socket groumd pin , but then again even all this are done if your IEC are not 3 pin or even is a 3pin US/UK but inside got no wire connected both ends your equipment still is not properly grounded. Connect any RCA's outer casing contact to the plug's ground is a easy way out , but this is not the correct way . in some aspect you are also sending leak back to the audio circuit and by doing so you are making multiple ground point for your amp. noise noise and more noise , what happen in time to come that over leak thru the ( - ) point get into your audio circuit ? high hum ? blown off the output tran's ? Do it right , do it right.......
exclusive Posted May 3, 2018 Author Posted May 3, 2018 In the first place , why there are leak ? where they come from and where they should go ? casing does not leak , but the unbalance of the output the power supply filtering circuit cause that acccess and this comomly from the pcb connected to the casing and from that same point connected to the main socket groumd pin , but then again even all this are done if your IEC are not 3 pin or even is a 3pin US/UK but inside got no wire connected both ends your equipment still is not properly grounded. Connect any RCA's outer casing contact to the plug's ground is a easy way out , but this is not the correct way . in some aspect you are also sending leak back to the audio circuit and by doing so you are making multiple ground point for your amp. noise noise and more noise , what happen in time to come that over leak thru the ( - ) point get into your audio circuit ? high hum ? blown off the output tran's ? Do it right , do it right....... I opened up and saw that there is cable connecting the Pcb to the IEC ground. can u advise how should I do it right? Sent from my SM-N950F using Tapatalk
econav Posted May 4, 2018 Posted May 4, 2018 1) find a 2gang or more extention bar and plug the 3 pins plug direct to wall socket. 2)Check that main cable you use to connect this amp to the socket ,all 3 wires are inside both ends. 3) plug this main cable to the extention bar and to your amp then power up. 2) use a test pen tip , touch on the casing and if lighted means the group is open. 3) use the same test pen insert to the ground contact on the ext bar ( if also lighted means your power core did pass the leak thru the wire ) 4) if this is the case , hv your 13A wall socket checked by a electrician for safey.
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