Tube Mic PSU Wiring Question

[Phrazemaster]

Hi gang, I'm building a tube mic and have a schematic, partly shown attatched.

I understand the schematic, theory, and even the math. What I'm not good at (yet) is making the leap from schematic to actual wiring.

This PSU has both a heater section, and a section for the rest of the mic. The schematic shows a common ground between the two.

My (perhaps) common sense tells me, even though both the heater and mic sections show a common ground on the schematic, to separate the grounds until connecting them at their own star points (or buses) and then tie them together right at the chassis star ground.

In other words, am I right in keeping these circuit sections separate since they have very different voltages, and then tying them together at a star point for the chassis? Or do I REALLY connect the wires exactly where the connection points show in the schematic (see the attached pic). I'm thinking they draw the schematics this way for clarity, but in actuality implementing the meaning for best results is different. Am I right?

Thanks in advance for any assistance. I R still a newbie.

Mike

 

[poctop]

The Idea , is think the ground as a reference voltage (0) for differents parts and function of a circuit , 
per example power ground, analog ground ,,,digital ground,,, chassis ground ,  each block will need to connect fatally at the same spot or level if you wish , after all , pumping electrons from your case  , the idea is to converge to each block at one spot at the end  and finally tie your case where they can pump the electron for your circuit

in your example, all the psu schematic is on the same reference, this is just becoming part of one circuit block
reference level,  Hence the Star ground  ,  this ensure you understand how to ground at the very basic.
the thing is !  if sometime we dont pay enough attention to what we are doing "grounding" then one might have "cyclic redondancy" (Loop) if you wish that create the Hum'sss,
here is a little link for more, this is just to give you an idea

http://www.geofex.com/article_folders/stargnd/stargnd.htm

 

[Phrazemaster]

Hi poctop, thanks for the reply and the link!

Although this article is fairly technical (for ME anyway!), and I have read it before, it appears my interpretation is correct: separate the circuit sections (blocks?) and ground them with their own bus, and then connect them "fatally" or together finally at the end in the star ground at the chassis.

Now I read something some time ago about star grounding that I want to share. I can't recall the article, but it made loads of sense to me. The article said, when you finally do ground everything at the single star ground location, make sure you do it in order of largest-smallest signal levels.

In other words, after the earth grounding to the chassis from the IEC, next is the psu grounding bus, then a smaller signal level bus (such as the audio section), and then the next smallest. Literally, to stack the grounds in order of largest to smallest current/voltage levels.

The concept was, to prevent your large psu currents from getting into your delicate signal grounds, put the psu ground first so it has first exit. Those electrons are not around any longer to get into your tiny signal ground and cause a loop! Like, men first, THEN women and children!

OK I realize this is simplistic, and any experts out there can correct me; I'm not stating this as fact, only what I recalled from an article

Thanks again poctop.

Mike