Well... such things are actually pretty common in lots of commercial designs (not just pure audio either) and often added as a means to cure some issue that occurred in use such as RF breakthrough. Ground traces on PCB's and even just wire has significant inductance and resistance that means no two points on the same conductor are actually electrically the same, particularly at high frequencies (such as RF).
I also wonder if the correct ground symbols are used or whether there should be some differentiation of chassis grounds and signal grounds and so on.
I also wonder if the correct ground symbols are used or whether there should be some differentiation of chassis grounds and signal grounds and so on.
The Chinese is a challenge, but the last one from them I made used that symbol for ground. This is an audio amp with wires in the 1 to 6 inch range for the most part, so I wouldn't expect significant voltage differences over a few inches that would make a resistor actually do anything.
There may be a reason for this, but even my grew-up-in-solid-state-era brain can't quite get it.
There may be a reason for this, but even my grew-up-in-solid-state-era brain can't quite get it.
It's a simple ground loop breaker.
In the PSU the ground is "signal ground", in near the input the R//C connected from signal ground to safety ground.
The wiring is correct, the marking of safety ground is misleading.
In the PSU the ground is "signal ground", in near the input the R//C connected from signal ground to safety ground.
The wiring is correct, the marking of safety ground is misleading.
I believe it's Ming Da MC-7R Preamplifier. You may want to search for it because there were few mods floating around on web.
Wow - that sure led down a big $$$ rabbit hole. I feel like about $220 for this thing is a deal even if I do have to build it myself. They give no guidance whatsoever on the physical wiring layout, what I posted is all you get.
The power amp worked out well, I knew from ham radio about twisting filament wires and not creating ground loops. If it has hum I can't hear it 🙂
The power amp worked out well, I knew from ham radio about twisting filament wires and not creating ground loops. If it has hum I can't hear it 🙂
