music signal in ground F5 PS?

[erez1012]

hi all
i have regular PS like in the F5 pdf, the center connected to thermistor -> to ground star. Everything works fine.

Decide to use the F5 20vdc PS to other component in the system (B1)

i connected the +20vdc and GND to regulator and to B1 buffer.

i see signal in the ground ! 100mv, its poison other components
try to connected the PS GND to earth -> down to 20mv.

What happen?

thanks

 

[AndrewT]

looks like you will need to re-write your question.

 

[Nelson Pass]

The thermistor should be connected between amplifier ground and chassis.
Chassis should be connected directly to AC Earth. Does your amplifier load
connect to AC Earth somewhere?

😎

 

[erez1012]

Thanks, the problem SOLVED. no sound signal in the GND
Till now, the speaker connect to earth and the PS connect to the Thermistor and the Thermistor to earth, maybe it’s the problem.

I decide to use the F5 PS for the other system regulator because it's very good PS, and its cost lot of money &place to build more +-15vdc.

Now as you can see in the scheme:
The earth connected to the Thermistor ->star
The F5 PS connected to star (I hope that’s what nelson said)
The speaker ->star
The B1 PS -> star (small star inside the B1 circuit -> main star)
The B1 sound analog signal GND-> DAC analog GND -> star
Etc

What prefer:
1)small star in every system (signal and PS) -> main star
2)every GND to main star (a lot of wire (antenna)) 😕

thanks Nelson Pass and AndrewT