Power Supply Meta Thread

Construction information for DIY projects, including the MS Mid Side Matrix, Elliptic Equalizer, Mastering Console, Phono Transfer System, Insert Switcher and the Dual Class-A Amplifier. You can post your baby pictures here.
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mediatechnology
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Power Supply Meta Thread

Post by mediatechnology »

This is a master list of power supply threads and links for audio projects.

Velleman K8042 "Symmetric" Adjustable Bipolar Power Supply https://proaudiodesignforum.com/forum/p ... ?f=7&t=672

Linear Single, Bipolar and Triple Output Switching Power Supplies for Audio Projects https://proaudiodesignforum.com/forum/p ... ?f=7&t=958

TDK-Lambda Single, Bipolar and Triple Output Switching Power Supplies for Audio Projects https://proaudiodesignforum.com/forum/p ... ?f=7&t=945

Meanwell Single, Bipolar and Triple Output Switching Power Supplies for Audio Projects https://proaudiodesignforum.com/forum/p ... ?f=7&t=943

Parts Express Linear LM317/337 Bipolar Power Supply Board https://proaudiodesignforum.com/forum/p ... ?f=7&t=983

JLM Power Supplies https://jlmaudio.com/JLM%20Power%20Supply.htm

Five Fish https://fivefishstudios.com/diy/psu2448/

Collective Cases viewtopic.php?f=7&t=1269
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mediatechnology
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Re: Power Supply Meta Thread

Post by mediatechnology »

Added Collective Cases: Collective Cases viewtopic.php?f=7&t=1269
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mediatechnology
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Switching Power Supply Comparison Using the Flat Moving Coil Preamp

Post by mediatechnology »

I made some comparative FFTs of the Meanwell P25A, Meanwell GP25A and the TDK CUT-35 to a linear benchtop supply.

The differences, with one exception, were underwhelming...

The load was the Flat Moving Coil Preamp with the gain set at 61.5 dB.
The source impedance was the internal 10Ω termination.
The Ein is around -140 dBu in all cases. (20-20 kHz measurement BW).
The ambient hum field of the room was nulled in all measurements by positioning the board.
The FFT is the Left and Right Outputs with the display open to 48 kHz. (FS=96K 24B FFT 65Kpt 5 sample avg.)

The Meanwell P25A is quieter when the 5V supply is preloaded. It is not loaded in this measurement.

The Meanwell GP25A, which replaces the original, is a very electrically noisy supply and no amount of preloading helps.
The GP25A's spread spectrum "hump" above 20 kHz pokes out of the noise floor.

Benchtop Linear Supply
Image

Meanwell P25A (discontinued)
Image

TDK CUT35
Image

Meanwell GP25A ("Green Power")
Image

The GP25A is an electrically noisy supply.
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