Post you SMPS noise spectrum measurements

[HerzMeister]

As far as an SMPS sending noise up the power lines, would using a power conditioner help keep such noise from contaminating other sensitive hifi equipment supplied from the same service panel?

 

[Extreme_Boky]

See posts #5 and #11:

Post in thread 'Filtered AC inlets and power conditioners will they work together?'

2024-10-19 12:48 am

Alas some powerline filters do more harm than good. They present a high impedance to noise, which might be good at keeping noise out, but they can also keep it in!

The low impedance of the mains can actually work as a noise sink. Put a high impedance filter in line, and the noise has nowhere to go. You get more noise at the device power plug than with no filter.
Yes, I have measured this, out to several MHz.

• Pano

• 

Post in thread 'Filtered AC inlets and power conditioners will they work together?'

2024-10-20 5:35 am

That's interesting and sort of what I was afraid of. My thinking was a filter being filtered could cause it's own effects just wasn't sure if it would be good or bad. I've never filtered inside a source or amp so that's why I questioned it. I built a new house in FL where the A/C compressor, air handler, and fridge run more often than not so I was thinking of things to suppress the bad stuff that comes from that. Plus lightning strikes and storms as well. We already had a few homes in our community get hit. I have a surge protector on the power meter and run surge protectors on...

• Extreme_Boky

• 

... but don't limit your reading to just those 2... the whole thread is pretty good.

 

[Mainframe]

Yes I know its not a value SMPS but FWIW some measurements I grabbed last year playing around with SMPS - Hypex PS500DIY +70V/-70V SMPS in a stereo class AB wolverine chassis. Not at all representative of wolverine distortion profile due to distortion in topping DAC as sine generator. Wolverine distortion way, way lower.

RCA input shorted -> speaker output to 8R non inductive 200W resistor -> E1DA ADC 35Vrms input-> laptop on battery.

50hz ~5W; REW on laptop on battery -> topping e30II powered from laptop -> rca to amplifier -> speaker output to 8R non inductive 200W resistor -> E1DA ADC -> laptop

You can see the 130-140khz switching noise. "see". Noise at 16khz is USB induced noise and varies depending on USB cable lengths and layout.


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E1DA self noise / noise floor no input connected for reference.

 

[Mainframe]

Oh and here's the SMPS1200A400 in the same chassis - a cheaper non-regulated (above ps500diy is regulated) 100khz switcher with no PFC.

Noise floor (input not shorted, E30II connected and idle). For some reason I didn't grab this in V scale, but I assure you the input voltage was calibrated correctly, so 0dbFS is 35VRMS as the E1DA ADC in its aux 1.7/35VRMS jumper config.

1khz 5w/8r 0dbFS 35VRMS - showing vanishingly low switching noise buried in the DAC noise shaping. As above, ignore harmonic distortion, not representative of the amplifier but instead inherent to the E30II DAC being used as the signal generator.