How clean is 3205000 power supply?

[Deleted member 9685]

AIYIMA sells this 3205000 power supply with many of its amplifier models.

In AIYIMA A07 TPA3255 Review (Amplifier), 3205000 seemed to have quite a bit of mains hum.
In AIYIMA A05 Review (Budget Amplifier), I couldn't see much mains hum from 3205000.

Can I assume that 3205000 has quality control issues or that amir got a better unit of 3205000 for the review of AIYIMA A05?

Has anyone measured noise from 3205000?

 

[AnalogSteph]

It's a 160 W floating SMPS, I'd be surprised if it didn't have some mains leakage looking to make its way to ground via input audio cabling. There'll always be some from the mains filtering. Not sure why the difference in testing, maybe the filtering is not symmetric with regard to L and N so plug polarity matters, and the mains inlet at the supply may be an unpolarized Telefunken "figure-8" jack so the cable can go in both ways?

 

[Deleted member 9685]

@AnalogSteph If I plugged a gounrded power supply, I wouldn't see as much mains hum in audio signal?

 

[solderdude]

Its double insulated so grounded wall sockets do nothing here.
These power supplies will have leakage currents. The way you plug them into a wall socket may influence the amount of leakage current.
It is possible some mains hum makes it into the DC.

 

[Katji]

... I'd never seen this before - so far I remember - a polarised C7 connector...[with a version trail of the image used, not surprising.]

 

[jst]

I find this kinda funny, I was looking for 3205000 when I bought mine since in my country Aiyima A07 doesn't include power source.
But I found one with similar number GZD-0325000 , the power cable uses C5 which is very unusual for me, in fact this was the first time I found something using that kind of connector.

No hum, but there is a hiss, need to put my ear close to the tweeter to hear it. Never really noticed though, until someone mentioned in in a post and tested for myself