| circuit.lt |
Hi,
I've made a few amps with LM3886T. They can be seen at: http://www.circuit.lt/?section=sch&page=lm3886t (sorry, only in Lithuanian, but you can still understand images ;))
In photo is older revision.
They work fine for me, but few visitors have reported, that their amplifiers are humming. For others - fine too.
Why could this happen? Is there anything wrong in PCB?
Regards,
circuit |
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| fosforo |
| quote: | Originally posted by circuit.lt
Hi,
I've made a few amps with LM3886T. They can be seen at: http://www.circuit.lt/?section=sch&page=lm3886t (sorry, only in Lithuanian, but you can still understand images ;))
In photo is older revision.
They work fine for me, but few visitors have reported, that their amplifiers are humming. For others - fine too.
Why could this happen? Is there anything wrong in PCB?
Regards,
circuit |
Could you post the revised schematics? |
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| Nordic |
Your circuit looks fine.
Humming possibly caused by power wires/transformer badly positioned in case.
Also builders should make sure the input and output jacks are isolated from the case.
braid power cables and use shielded signal cables inside the box, or twist a pair of cables tightly if you don't have shielded cable.
Keep cable between input jack and pcb as short as possible... |
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| circuit.lt |
Schematics and PCB are here:
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