The official GroupDIY 511 Help & Support Thread

[[silent:arts]]

John, with phantom power on measure DC with your multimeter between pin2 & 1 and pin3 & 1.
If you don't read 48V check continuity between pin1 to your PSU chassis connection etc

 

[Monoklang]

On the working rack I read 48v, but not on the "faulty" one. So you're on to something!

If I measure between pin 2&3 and the racks ground I read 48v

I have continuity between pin 1 and the racks chassi
...                      between pin 1 and the PSU chassi
...                      between pin 1 and star ground
and so on...
everywhere but...
when I measure between pin 1 (rack) and ground on fuse board and regulator board the continuity is GONE.

So that must be it right?

But if the screw (above the ground wire on the regulator board) won't show continuity, then the wiring could be ok?
So what to do next?

Thank you very much!
John

 

[Monoklang]

Hmm, after a lot of testing... I'm more confused then before.

PSU A have none continuity between ground and chassi
PSU B have have continuity between ground and chassi

I measure between Fuse board and regulator board and star ground)

I've built them exactly the same way and none of them have a jumper between the GND/chassi (at the AC inputs)

Witch way should it be, I have read somewhere that in the PSU chassi and ground connects, but where?
In my PSU, star ground connects with chassi at regulator board, ground goes to fuse board
then ground goes from the fuse board to the xlr and the other chassi (regulator board) goes to the xlr.

So do they ever meat?

Regards
John

 

[Monoklang]

I jump wired the chassi to the ground on that regulator board (at the AC side) that "didn't already had connection" (in some strange way?)

Then I could measure 48v between pin 1-2 & 1-3, Buzz is gone and then phantom powered microphones works!

So the only question left is why I didn't have to do this thing with the other regulator board? There should be no difference between them, right?

John

 

[jsteiger]

John

What Rev of VP26 do you have? I am assuming Rev A. On the Rev B boards, I have a 10R between CHA and GND on the PCB to eliminate the issue of a rack having CHA floated. There have been many reports of some rack manufacturers floating the card edge Pin 1, for some reason.

You should have a CHA to star ground wire connection from the main PSU PCB. You should also have another GND to star ground wire connection from the main PSU PCB. Volker has these pads on the ends of the AC inlet header block.

The GND config may be slightly different when incorporating Cemal's Fuse Boards, but both of these points on the main PSU PCB need to find their way to the star ground point.

 

[Monoklang]

Yes it's REV A on the VP25-VP26

Ok, so it's not enough to connect chassi and ground together on the main PSU boards? And then Chassi to star ground?

Thanks
John

 

[jsteiger]

In therory, the first and only place they should connect is the star ground point, along with earth from the IEC inlet.

 

[Monoklang]

Ok, it all makes sense. I will take care of that tomorrow. Thanks!

John

 

[Monoklang]

I connected ground to star ground and then everything sounds 100% pure happiness

 

[jsteiger]

I connected ground to star ground and then everything sounds 100% pure happiness

Excellent! Thanks for the update.  8)

 

[Monoklang]

Well thanks for the superb advice. Now my racks are ready for both love child's and some vp28's...

 

[MarshallCS]

Has anyone connected what looks like the Dsub connectors at the top of the pcb? Is there a reason not to do this? What parts would I need to add this in (it seems like it would be easier to add it now than later) What about cutting the backplate?


Thanks so much. I just finished soldering the card connectors.... tomorrow the jumpers and the xlr's hopefully.

Jeff - I hope that new psu comes out soon. I also sent you an email.


Thanks all,
Marshall

 

[zayance]

Has anyone connected what looks like the Dsub connectors at the top of the pcb? Is there a reason not to do this? What parts would I need to add this in (it seems like it would be easier to add it now than later) What about cutting the backplate?


Thanks so much. I just finished soldering the card connectors.... tomorrow the jumpers and the xlr's hopefully.

Jeff - I hope that new psu comes out soon. I also sent you an email.


Thanks all,
Marshall

http://www.groupdiy.com/index.php?topic=47653.msg600335#msg600335

 

[jsteiger]

...Jeff - I hope that new psu comes out soon. I also sent you an email....

The parts arrived at the anodizer at the beginning of last week. I expect them to be to me by the end of next week at the latest. I then need to ship the front panels to the silkscreen shop. They are finally just around the corner. All the heatsink side panels have been here for almost 2 weeks now.

 

[MarshallCS]

Thank you Jeff and Zayance!

 

[jplebre]

Hey guys

So, I was trying to finish the rack side of my 511, and this happened:

Did something change? chunger's looked more like http://www.groupdiy.com/index.php?topic=41617.msg527506#msg527506 (few pictures down).

this is my soldering:

I did allow myself some space, but not that much me thinks.

My question is: what do you think, safe?

 

[sahib]

The space available behind the 7 pin has always been a bit tight. You can get round it by using thinner gauge wire. It won't make much of a difference in that length.

Chunger seems to have used spacer to bring the connector forward a bit.

 

[jplebre]

Since I have the plugs on a MOLEX, it's easy for me to just put in a spacer like chunger.
Is it much of a deal though? Wondering about heat mainly?

 

[sahib]

Not at all.

 

[Sean Halley]

Hey guys - sorry to ping in here, but when searching for the answer to this question I wasn't successful in sifting through all of the grounding threads for this answer....

I just built the 51x rack (along with a bunch of other stuff), and it seems to have come out nicely (it's an easy build - well done on the design!), but I didn't build the rackmount supply designed to go with it, mainly because I have piles of PowerOne high current power supplies lying around.

My question has to do with how to connect grounds from two separate supplies to the 51x:

I have one PowerOne 3.5 amp bipolar supply that I'm going to use for the +/- 16v leads, and a separate high-current supply for 48V phantom - both fed individually from wall AC.

What is the best way (or is there one) to connect these two separate supplies to the 51X rack and have the voltages behave normally for the modules installed? Is it do-able?

Thanks dudes! Much appreciated!

S..