HQ Low noise 4-quadrant PSU with 2xLM3886

Here is one very interesting and unique schematic for high quality 4-quadrant PSU based on 2 x LM3886 for use in audio applications.
Design is done by Macola in 2012.

Key specification
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Input voltage: +/-15V to +/-37V
Output voltage: +/-5V to +/-30V adjustable
Output current: <2A
Output power: <50W (Vcc * Iout < 50W)
Power supply rejection (PSR): >=70dB
Noise: <0.5mV
Ripple: <1.3mV @0.5A load
Line regulation: <10mV for input voltage +/-15V to +/-37V
Load regulation: <10mV for load in range 0-2A
Transient response: <4uS for injected 20Vpp square wave with Ri=50Ω
Supply current: 120mA - 130mA depending on input voltage
Supporting remote FB for cables compensation.

Other notes:
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Input voltage must be 5V higher than maximum desired output voltage.
Output voltage is set by R22 variable resistor (multi turns recommended).
All GNDs must be realized as star (single point) connections!
Heat sink for LM3886 adjust according to expected dissipation - Pd (see LM's application note).

C15, C17 and C16, C18 put as close as possible to LM3886.
C13 and C14 adjust as >1000uF per 0.5A of load.

Supplying device (load) can have arbitrary values in capacity of it's input (bulk) capacitors.

PS: Anyone who see Macola's bridged amplifier "Bato MM" will see similarity with this PSU ;)
http://www.diyaudio.com/forums/chip...-lm-bridge-consider-try.html?highlight=batomm
 

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  • Low noise regulator.png
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