Even if a similar question specifically applied to a phono preamp, I think the question on how to better star ground a schematic when you design the pcb is a much larger issue.
On analog audio it applies to all types of circuits, be it low noise or not. Power amplifiers are certainly not low noise designs, but you have be careful with the input stage, where signals are more susceptible to different type of interference.
Star grounding is relatively new concept, which was very talked about and discussed in the late '80s and '90s, probably when DIY became more demanding and sophisticated.
Perhaps people can come to this thread and tell about what worked for them, and how it was implemented to cure hum and RFI, which became a problem when cell phones got popular. Local decoupling became almost an art, complementing star grounding when it existed or solving the noise problem when it did not.
I will google about this matter and look here in DIYAudio a bit too.
Let's hope people get interested.
On analog audio it applies to all types of circuits, be it low noise or not. Power amplifiers are certainly not low noise designs, but you have be careful with the input stage, where signals are more susceptible to different type of interference.
Star grounding is relatively new concept, which was very talked about and discussed in the late '80s and '90s, probably when DIY became more demanding and sophisticated.
Perhaps people can come to this thread and tell about what worked for them, and how it was implemented to cure hum and RFI, which became a problem when cell phones got popular. Local decoupling became almost an art, complementing star grounding when it existed or solving the noise problem when it did not.
I will google about this matter and look here in DIYAudio a bit too.
Let's hope people get interested.
Star grounding is used to stop ground currents modulating the ground line.
The worst culprit is a bi polar power amp power supply.
The charging impulses into the smoothing caps tend to be short high power current pulses.
Any resistance in the pcb tracks and you get ground modulation.
The trick is to keep power supply separate.
The worst culprit is a bi polar power amp power supply.
The charging impulses into the smoothing caps tend to be short high power current pulses.
Any resistance in the pcb tracks and you get ground modulation.
The trick is to keep power supply separate.
Most of my designs are modular in nature, meaning signal stages, filament and HV Vcc are all on seperate boards, and I use ground planes on each board, each of these boards have a single ground that goes back to the main HV supply which is grounded at one point to a PCB standoff which gives me my single ground point to chassis, this has given me dead quiet gear for as long as I can remember but the learning process has been brutal!!