Hello everyone
I wanted to ask about a problem I'm having with a class AB(TDA7397) guitar amp I'm building and see if anyone has any idea about how to tackle this.
So the problem is that when I'm powering the amplifier with any two prong smps adaptor there's a loud 50Hz noise coming out of the speaker.
From my understanding this is noise from leakage current caused by the Y capacitors in the smps. I also tried medical type supplies with low leakage current but again no luck.
When I touch the metal enclosure of the amp to mains ground the amp is completely silent, also when I touch the metal parts of the guitar or amp the noise gets reduced.
The only solution so far has been to use a laptop type supply whose primary side gets grounded to mains.
From your experience are typical smps adaptors unusable with amplifiers? Any ideas on how this could be solved or improved?
Thanks in advance.
I wanted to ask about a problem I'm having with a class AB(TDA7397) guitar amp I'm building and see if anyone has any idea about how to tackle this.
So the problem is that when I'm powering the amplifier with any two prong smps adaptor there's a loud 50Hz noise coming out of the speaker.
From my understanding this is noise from leakage current caused by the Y capacitors in the smps. I also tried medical type supplies with low leakage current but again no luck.
When I touch the metal enclosure of the amp to mains ground the amp is completely silent, also when I touch the metal parts of the guitar or amp the noise gets reduced.
The only solution so far has been to use a laptop type supply whose primary side gets grounded to mains.
From your experience are typical smps adaptors unusable with amplifiers? Any ideas on how this could be solved or improved?
Thanks in advance.
