I have a question with regards to the actual purpose of R0 in Aleph 30 circuit. It's been said that this resistor breaks ground loops, but I can't quite figure out how it does that. I mean, would it make any difference if R4/R5 were connected directly to signal ground, as it seems like signal ground connects to those resistors through R0?
http://www.passlabs.com/downloads/old product/a30manr0.pdf
http://www.passlabs.com/downloads/old product/a30manr0.pdf
I thought initially that this is a resistor separating signal ground from output ground, but it does not seem to be a case (you can notice such resistor on National's LM4780 evaluation board). So in most cases it's probably not needed anyway ( as I'm also not using the input diodes).
I'm still considering improving the ground scheme on the A30 board. I recall Zigybait commenting that running separate ground paths from current source circuit and the signal ground to main star ground point improved performance.
I'm still considering improving the ground scheme on the A30 board. I recall Zigybait commenting that running separate ground paths from current source circuit and the signal ground to main star ground point improved performance.
I recall Zigybait commenting that running separate ground paths from current source circuit and the signal ground to main star ground point improved performance.
You can try to put an about 24V Zener diode between R13 and supply (-). Than you don’t need a connection R13 to the ground.
As I recall, R0 simply helped to break the RCA connection
loop going back to the source equipment. There was a
little less noise this way, and both the input and feedback
referenced to it, so it didn't compromise performance. If you
don't need it, there's no requirement to use it.
loop going back to the source equipment. There was a
little less noise this way, and both the input and feedback
referenced to it, so it didn't compromise performance. If you
don't need it, there's no requirement to use it.
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