I didn't understand what is the cause of the ground leakage if the above mentioned measurements are not zero or close to it. Many thanks
post #14 , problem declared
post #24 , some relations to GND reported ( but not clear is it just buzzing in speakers or what) ;
post #27 Radule pointed possibility of problems with RFI filter parts
post #29 ground leakage mentioned
post #30 I asked for specifics - is it ELCB , or regular (automatic ) fuse tripping ; I also gave you specific parts positions , for your tech to check
post #32 , I repeated the same , with some more explanations
now we are practically running in circles ....... especially counting on fact that any (really) skillful tech should decipher exact culprit in hour or even less
besides that , we are not here on any side - seller's or buyer's ..... we are trying to help in solving problem with the amp , and I really can't care less for any trade operation here
as a fact - even with unquestionable ground leakage (being big enough to invoke ELCB action) , amp would flawlessly operate in house with old type melting fuses and without ELCB installed
post #24 , some relations to GND reported ( but not clear is it just buzzing in speakers or what) ;
post #27 Radule pointed possibility of problems with RFI filter parts
post #29 ground leakage mentioned
post #30 I asked for specifics - is it ELCB , or regular (automatic ) fuse tripping ; I also gave you specific parts positions , for your tech to check
post #32 , I repeated the same , with some more explanations
now we are practically running in circles ....... especially counting on fact that any (really) skillful tech should decipher exact culprit in hour or even less
besides that , we are not here on any side - seller's or buyer's ..... we are trying to help in solving problem with the amp , and I really can't care less for any trade operation here
as a fact - even with unquestionable ground leakage (being big enough to invoke ELCB action) , amp would flawlessly operate in house with old type melting fuses and without ELCB installed
The point is: yes, the amp works fine in a house with old type fuses and without ELCB BUT in this case when he touched the amp he got a shock. Am i wrong? Is it normal to get a shock from an amp? One of these days the amp will be inspected by a good technician and i'm sure thanks to your suggestions the issue will be find out easily. Thanks again
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A word from the seller. Always check and listen when you buy or sell.
Nothing would have changed in this case with this amp technically. But the situation would be less stupid. I had no business driving one hour to another district when I sold the amp but I did it as a service from one audio enthusist to another. I understand the buyers position but who could presume the amp could have this kind of “evil magic”.
Me and others touched the heatsinks too and never felt anything.
As I told the buyer, lets hope its really those two small capacitors and a quick and cheap fix.
I suppose it shouldn’t be expensive. It played and played well in my system on saturday morning. Great peace of gear and this kind of support is amazing.
Nothing would have changed in this case with this amp technically. But the situation would be less stupid. I had no business driving one hour to another district when I sold the amp but I did it as a service from one audio enthusist to another. I understand the buyers position but who could presume the amp could have this kind of “evil magic”.
Me and others touched the heatsinks too and never felt anything.
As I told the buyer, lets hope its really those two small capacitors and a quick and cheap fix.
I suppose it shouldn’t be expensive. It played and played well in my system on saturday morning. Great peace of gear and this kind of support is amazing.
Hi Nikica nice to have you back here. Tonight the amp will be checked and i really hope it's only the two small capacitors the gentelmen suggested. I'l keep you and the forum posted.
The amp was checked by the technician and the issue was the small capacitors like suggested. He also found out bias needs to be adjusted (a little tricky without schematics). So the amp will be in good shape soon. I want to say thanks, thanks, thanks to Zen Mod, Wayne, Mr Pass and everyone contributing to the thread!
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I'm guessing your technician found the bias of the two channels no longer match.
It might be a good idea to check with PL what the proper value should be.
It might be a good idea to check with PL what the proper value should be.
Lacking anything else, the correct bias is the one where the sinks rise
to 50 deg C. in room temperature environment after an hour.
to 50 deg C. in room temperature environment after an hour.
Yes! Good news. Thanks everyone. No more evil magic.
Bias is idle current. I never checked that but that corresponds with heatsink temp and it was about equaly hot in both sides.
DC offset should be close to zero. Small pop on switching on / stand by is what it makes.
Its in factory specification.
Bias is idle current. I never checked that but that corresponds with heatsink temp and it was about equaly hot in both sides.
DC offset should be close to zero. Small pop on switching on / stand by is what it makes.
Its in factory specification.
some of it can be grasped from here : Pass Labs X150.5 , checking/adjusting offsets ,Iq and gain | Zen Mod Blog
That sounds like dc offset, which should be kept low.
It is spec'ed as <100mV in the owner's manual. See last page:
https://www.passlabs.com/sites/default/files/x150_om.pdf
Very good on getting it running those caps where a bit large by today's standards.
I remember Venice especially the Sepia.🙂
I remember Venice especially the Sepia.🙂
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