1-box DIY Music Streamer (2nd build)

I designed two linear power supplies (LPSU), both dual regulated. This build is the second design where it uses dual LM1084.

IEC inlet and rocker switch
Toroidy custom transformer used in this build

It’s amazing seeing toroidal transformers are more size friendly compared to R-core. The R-core transformer from Ekco Electrotech, China is rated 120V, but due to its geometry and mounting method, it needs larger footprint compared to 225VA custom toroid.

225VA toroid vs 120VA R-core from China, look at the size
Preparation for toroid transformer installation
LPSU boards and motherboard installed
ATX LPSU with dual LM1084 per rail

This ATX LPSU board with dual stage regulation using LM1084 is bigger since it can handle up to 5A, and to ensure low ripple under maximum load, 3 smoothing capacitors, each 10,000uF, are needed instead of 2 in the other design. This LPSU is different from the other design since it is always on. The LM1084 does not have shutdown pin – it’s only a 3-pin voltage regulator. If always on DC rails are connected to the motherboard, the chassis power LED will always lit, even when CPU shuts down. To address this problem, TI’s TPS3510 is used in this design to accept PSON signal. It will give PGO signal immediately upon PSON trigger. The FPO pin is used to drive onboard LED and also the chassis power LED. So the chassis power LED wires go into this LPSU instead of the motherboard to ensure chassis LED is lit when motherboard is powered on through the chassis push button.

Motherboard
ATX power supply cable installed
SSD tray installed
SSD tray secured
Top view

By Anwar

Dr. Anwar Ali is a consultant in the area of Operations Research / Decision Science. During his free time and as a side business, he builds high-performance and moderate-cost music streamer.