Preamp Power Supply

lupusaudio

New member
Hello,
I’m new in this group and I want to share my lab analog power supply especial designed for high end preamps.
with +/- 22 Volt supply voltage ( I like this ! )
The performance is pretty good, low noise low ripple and hum are the key aspects. You find a measurement (Conditions: 2x12 V, Iload: 2x250 mA ; Analyzer: Audio Precision One) of the noise spectrum compare with battery and commercial stuff in the attachment.
Conditions: 2x12V, 2x250mA
Specification:
Output Voltage: 2x12 Volt - 2x26 Volt, adjustable
Current: 2x250 mA ( depends on In-/Out Voltage )
Protection: reverse voltage ,reverse biasing, mutual shutdown

Comments are welcome...
 

Attachments

  • LabPowerSupply_Spectrum.pdf
    26 KB · Views: 428
  • PS221.pdf
    35.2 KB · Views: 431
Last edited:

norazmi

diysmps Senior Member
nice scheme, what about uf4001 diode? if we change to 1N4001 does it effect the efficiency, noise and hum?
 

lupusaudio

New member
I never did any tests and measurements with the 1n400x family. There are some audio experts who prefer fast switching diodes. I guess the more important part in the power supply design are the two-stage ripple filter after the rectifier for filtering out diode switching noise and hum....and the regulators.
 

norazmi

diysmps Senior Member
Not yet, but i see on many 12vdc car pre-amp use 2 x to-92 transistor feed with small toroids to have +/- 15 vdc, but i`m not yet investigate how it works, do you have schema for it microsim?
 

lupusaudio

New member
Yes, but always followed by a analog design as point of load regulator for better noise performance.
I have used the parts of the “simple switcher” family from Nationl Semiconductor; works fine.
 
Top