DAC AD1862: Almost THT, I2S input, NOS, R-2R

I'm working on my dac now. It's almost complete. Yesterday I added +5V on Jlsound - I don't know does it make sense? Anyone compared with and without?
Also I want to add some display for tech info - still looking that. I thinking to short the psu wires - do I need to?
Give me some advice on what else to do.

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That cooler on the regulating transistor (BD139 i think) also seemed too hot to me. I put a bigger cooler and reduced the supply voltage of the XMOS part to about 4.1V. Put one Si diode (1N4001) in the positive supply line to JLS. Now in the summer, the temperature of that cooler is around 50C. It will work like this for 100 years. 🤣
 
4,1V? - is that enough?
Yes
From JLS manual: Using two external power supplies. One must cut external power supply jumper
located on the bottom side of the board, then provide external power supply for
USB side (400mA; 4.0V to 5.3V) on H1.1 and H1.2, provide external power
supply to H3.17 and H3.19 (100mA, 4.5V to 5.3V).

Slightly bigger cooler + slightly lower power supply voltage = 15C difference.
I don't know how important it is, but a lower temperature is certainly more favorable.
 

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It is possible to reduce the voltage on an adjustable regulator, but I use a fixed regulator LM1117T-5.0, so I added a diode. A 2.2 ohm 2W resistor can also be placed instead of a diode. TO220 cooler, the largest that can fit without touching anything. I isolated it from the transistor with a silicone pad.