official GDIY51PSU Help & Support Thread

[sahib]

Enjoy. I am calling the day. In the last two nights I have been up until 2-3:00 AM doing my accounts and VAT return and getting up early. I am totally zonked. Good night.

 

[unwrittenmike]

all parts always have to be isolated from any heat sink. period.

Hi guys... I am a total newbie to electronics... this is my first project...

Referring to the quote above... I am close to finishing my power supply and I think I might have made a crucial mistake. The part connected to the on board heat sink doesn't have any insulation besides the sil pad... in the kit I received there were only four screws that had the little plastic insulators on them... so I assumed that these four screws were for the parts attached to the bigger off board heat sinks...

Is the on board heat sink connected to the circuit via the ground?

Is it fine to assume that in this specific case it is fine for the on board heat sink to have no insulation between itself and the part if it isn't connected to the circuit?

This project has been an awesome learning experience so far.. hoping when I finally power this thing up nothing fries! haha

Thanks,
Mike

 

[[silent:arts]]

the onboard heatsink (+48V) isn't connected to anything.
electronically nothing will blow or smoke if the regulator isn't insulated from it.

but once you touch it accidently with your screwdriver making a short to ground etc you will know why it should be insulated anyway ;D
this things happen in real life conditions

 

[New Soul Rebel]

;D My power supply is singing its heart out! Lovely, and with the good grace of a ballerina, Cemal has deftly floated his way through my issues while maintaining his position as King Don of the 51x world! I am proud...
??? : :-\
Until I began working my way along the rack. It seems that the first two channels work perfectly but channels 3-11 don't work at all. Hahahahahah/LOL. Its ******* typical!

After all my energy and efforts in getting the powersupply put together so dilligently, i've obviously either missed a step or ****** up iwht a bad solder or something on the ******* rack!

Ok... rant over. Any ideas what the blinking heck i've done wrong guys?

M

 

[jsteiger]

Matt,

When you say "don't work at all" what do you mean exactly? No +/- voltage rails, no audio in or no audio out? How did you test them? If you think something is amiss, take your modules out! Use your DMM to probe things.

Cheers, Jeff

 

[New Soul Rebel]

Ok Jeff, I have some more info

I have checked channels 3 and 11 with standard dynamic mic. Work perfectly. No Phantom though.

BUT then I plugged in a condensor mic and engaged the phantom on the VP312 and all of a sudden the speaker WHOOFED

christ, I am becoming the earth i think!!!

Yeah so, basically every time I touch the phantom switch on the pre and touch the case of the mic (a standard brass SE Electronics SE2a) my signal light comes on the channel on the and I get hum. Is this an earthing problem do you think Jeff? Its silent if I don't touch it.

 

[jsteiger]

Matt,

I would take all the modules out first. With your PSU on and rack where you can get inside of it easily, set your DMM to DC volts and probe all 5 power rails. Be super careful not to touch 2 pins at once and short them out. Verify the proper voltage at the proper pins. Here is your reference. http://51xaudio.com/alliance/pinout.html

Did you set your trimmers for all 5 voltage rails on the PSU PCB?

Jeff

 

[New Soul Rebel]

To be clear jeff, where do I ground my black multimeter, I can only access the front. The whole rack is screwed down. Do I need to literally connect to each of the power rails on the EDAC? Obviously tricky to do this from the front.

 

[New Soul Rebel]

: so bloody frustrated with this. I did so well on the power supply. I am as certain as, that the problem is at the rack end not the power supply. Cemal and I went through it step by step, plus all the voltages going out were spot on.

Would it be the soldering on the power cable? To my mind, why would channels one and two work fine if the cable was the issue?

I will go through it carefully and check.

 

[jsteiger]

To be clear jeff, where do I ground my black multimeter, I can only access the front. The whole rack is screwed down. Do I need to literally connect to each of the power rails on the EDAC? Obviously tricky to do this from the front.

To any Gnd point on the backplane.

 

[New Soul Rebel]

yo jeff

am i checking voltage on just

24-
24+
48
-16
+16

???

or anything else?

i have no jumpers at all on my PCB.

I am using only 1 chassis point directly to the neutrik.

M

 

[New Soul Rebel]

Jeff

To confirm (I have just checked) Every EDAC is carrying the right amount of voltage across the PCB.

Exact same readings (I think) as on the PSU test this morning. the rack is taking power okay it seems.

BUT, i've ONLY checked the mains rails and the phantom power.

Process of elimination... what next? it feels like an earthing problem to me. I am getting phantom power on the first two channels and 48v dc to all the remaining channels, yet no phantom power on the module. nothing wrong with the modules, I've just checked EVERY ONE in my lunchbox.

M

 

[jsteiger]

Matt,

Did you say you have no jumpers or headers on your PCB? You know where pin #1 for each XLR goes to either Gnd or Chassis? I hard wire jumpered all of mine to Gnd there. That could be the issue if you have no connection.

Jeff

 

[New Soul Rebel]

Jeff


When you say hard wired

A: Did you do this from the back side of the back plane? Have you got a pic by any chance?
B: did you hard wire on both upper and lower neutrik (i.e. male and female)

if i do this, is it meant to help improve grounding?

Honestly, I think I have a short somewhere. It literally lit my M Audio 1814 signal light permanantly when I touched mic and phantom switch on vp312.

Luckily no damage done at all. But its confusing really. Heck, every time i get an email or post from you guys i'm just on another huge learning curve.

M

 

[jsteiger]

Like this Matt. Cut off lead from a diode or something.

 

[New Soul Rebel]

Jeff

Is there any harm in doing this on every channel?

 

[Ptownkid]

no, you are supposed to do all channels

 

[kepeb]

i think i will defo do that if another rack comes around, saves a lot of faffing with jumpers!

 

[jsteiger]

Is there any harm in doing this on every channel?

no, you are supposed to do all channels

What he said.  ;D

Just be consistent and do all the same.

 

[New Soul Rebel]

Is there any harm in doing this on every channel?

no, you are supposed to do all channels

What he said.  ;D

Just be consistent and do all the same.

What? Do all channels? Did I miss something? But won't this F*ck my system or something? (voice in head ???) "No. No. No. Boy! Just do all channels! :"
And what was the other thing you said? :-\... I must be incontinent? (voice in head) but I'm not incontenent (am I? ), Not Incontinent dear boy, consistent 8). Ahh yes, now I remember. Solder pin1 to ground lalala  ;D

;D "here we go gathering nuts in may falala solder away!"