[BUILD] CAPI Dual VPR & 51x Floor Box PSU~Official Support Thread

[jsteiger]

What does a knocked rail entail?

Most likely just changing the fuse inside the PSU. The important thing is to find out what took it down. I would assume it has something to do with the last module you loaded. With the module not loaded in the rack or under power, I would check DCR from gold finger #12 to #5 and then from #14 to #5. Set your DMM for under 200Ω since you are looking for a direct or close to it short. If you find a low resistance, remove one opamp and remeasure, then remove the 2nd one and remeasure. I guess that is assuming that your 3rd module has 2 opamps. What is the 3rd module?

 

[nashflashcrash]

What does a knocked rail entail?

Most likely just changing the fuse inside the PSU. The important thing is to find out what took it down. I would assume it has something to do with the last module you loaded. With the module not loaded in the rack or under power, I would check DCR from gold finger #12 to #5 and then from #14 to #5. Set your DMM for under 200Ω since you are looking for a direct or close to it short. If you find a low resistance, remove one opamp and remeasure, then remove the 2nd one and remeasure. I guess that is assuming that your 3rd module has 2 opamps. What is the 3rd module?

3rd Module is a VP26 w/gar2520 kit.

DCR = card connectors, correct?
Unless I'm doing it wrong, I get no resistance #5 to #14 on any of my modules regardless of opamp in or out.

 

[jsteiger]

What does a knocked rail entail?

Most likely just changing the fuse inside the PSU. The important thing is to find out what took it down. I would assume it has something to do with the last module you loaded. With the module not loaded in the rack or under power, I would check DCR from gold finger #12 to #5 and then from #14 to #5. Set your DMM for under 200Ω since you are looking for a direct or close to it short. If you find a low resistance, remove one opamp and remeasure, then remove the 2nd one and remeasure. I guess that is assuming that your 3rd module has 2 opamps. What is the 3rd module?

3rd Module is a VP26 w/gar2520 kit.

DCR = card connectors, correct?
Unless I'm doing it wrong, I get no resistance #5 to #14 on any of my modules regardless of opamp in or out.

OK thats good now what about #12 to #5? #14 is -16V and #12 is the +16V rail.

 

[nashflashcrash]

What does a knocked rail entail?

Most likely just changing the fuse inside the PSU. The important thing is to find out what took it down. I would assume it has something to do with the last module you loaded. With the module not loaded in the rack or under power, I would check DCR from gold finger #12 to #5 and then from #14 to #5. Set your DMM for under 200Ω since you are looking for a direct or close to it short. If you find a low resistance, remove one opamp and remeasure, then remove the 2nd one and remeasure. I guess that is assuming that your 3rd module has 2 opamps. What is the 3rd module?

3rd Module is a VP26 w/gar2520 kit.

DCR = card connectors, correct?
Unless I'm doing it wrong, I get no resistance #5 to #14 on any of my modules regardless of opamp in or out.

OK thats good now what about #12 to #5? #14 is -16V and #12 is the +16V rail.

#5 to #12 (attached picture above) are 2M+ on the VP312 and VP26, and 286k for the VP28.

 

[jsteiger]

#5 to #12 (attached picture above) are 2M+ on the VP312 and VP26, and 286k for the VP28.

OK that is all fine and will not knock out your PSU. I would test the opamp from the last module. Was that built from a kit?

 

[nashflashcrash]

#5 to #12 (attached picture above) are 2M+ on the VP312 and VP26, and 286k for the VP28.

OK that is all fine and will not knock out your PSU. I would test the opamp from the last module. Was that built from a kit?

It was,  gar2520.

How do I go about testing?

 

[jsteiger]

#5 to #12 (attached picture above) are 2M+ on the VP312 and VP26, and 286k for the VP28.

OK that is all fine and will not knock out your PSU. I would test the opamp from the last module. Was that built from a kit?

It was,  gar2520.

How do I go about testing?

Well, I would replace the fuse in the PSU and make sure the +16V is correct. Then insert the new module with no opamp. I assume all things will still be fine. Then install the opamp and reinsert the module. If it knocks out your +16V rail again, there is a build problem on that opamp  Also, are the amps seated right? http://capi-gear.com/catalog/DOA_Install.php

 

[nashflashcrash]

#5 to #12 (attached picture above) are 2M+ on the VP312 and VP26, and 286k for the VP28.

OK that is all fine and will not knock out your PSU. I would test the opamp from the last module. Was that built from a kit?

It was,  gar2520.

How do I go about testing?

Well, I would replace the fuse in the PSU and make sure the +16V is correct. Then insert the new module with no opamp. I assume all things will still be fine. Then install the opamp and reinsert the module. If it knocks out your +16V rail again, there is a build problem on that opamp  Also, are the amps seated right? http://capi-gear.com/catalog/DOA_Install.php

Its definitely the new opamp. I'll go ahead and order a fresh one.

I did pop the +48v fuse just powering up my old modules. They're performing fine with a new one, but is that something to keep an eye on?

Thanks for the quick responses (and the learning experience), Jeff.

 

[jsteiger]

I did pop the +48v fuse just powering up my old modules. They're performing fine with a new one, but is that something to keep an eye on?

This it totally not normal.

 

[kevinkace]

About ready to power up for the first time!

http://i.imgur.com/zA9B356.jpg
http://imgur.com/zhuWWjU.jpg

 

[kevinkace]

Well blew the IEC fuse on first power up!  All the other fuses look intact.

I noticed I didn't have the heatshrink down over the ends of the Fastons,  Could current have jumped?

 

[kevinkace]

Maybe I was using the wrong fuse, as I picked up some 1A250V slow blow fuses in preparation for trial and error fixing, but it powered up and all voltages are now dialed in.  ;D

 

[kante1603]

Maybe I was using the wrong fuse, as I picked up some 1A250V slow blow fuses in preparation for trial and error fixing, but it powered up and all voltages are now dialed in.  ;D

Trial & error fixing on mains voltage is never a good idea  8)


Have fun,


Udo.

 

[Kevinkmny]

Secondary Toroid wiring question...

My apologies in advance but it doesn't seem clear to me from the build documentation how to connect the secondary toroid wiring.

It appears as though the pics are from a 51x build ?

Do I simply attach them in sequence per the polarity markings starting with the red pair on down the line?

Thanks!

 

[jsteiger]

The only pair that is different is the 48V pair of leads. For a 51x toroid they are white and for a VPR toroid they are black. Everything else is the same.

 

[Potato Cakes]

Hello friends!

I managed to put one of the floor PSU's in a single rack space that was 7" deep. I had to place the big caps and regulators w/ heat sinks off board. I used two transformers as the one with the kit is too tall. One 2x16 and one 2x24. I'm just doing VPR modules so I didn't need the 24V rails. The 2x24 transformer had the secondaries wired in series for phantom power. I was able to barely get the top cover on, as the actual chassis isnt quite 1U space tall. If I used a case that was flush with the front panel it would have made things easier. Also, if I wasn't so rushed, I probably would have just got one of the Total Audio Control rack PSU kits so it would have looked nicer. But where is the fun in doing things easy? It's much more exciting working late into night free handing all the metal work with a cordless drill and a Dremel tool. Fired up perfectly the first time, though. Thanks to Jeff and Volker for this design.

Thanks!

Paul

 

[Potato Cakes]

Another Pic.

 

[Potato Cakes]

Another.

 

[Potato Cakes]

Last one.

 

[hanso]

Thought I should share this:Some of us german or european builders seem to have slight difficulties with the transformer wires and their colours,which one goes where etc..
I made a little pic using the transformer description on the classic api site as a template (mea culpa Jeff!) and modified it to german colour coding.You´ll find the pdf at the end of this post.
I´m not sure if this is the same trafo Cemal sells,I got mine from Volker.Maybe someone can chime in here?

Here are some pics in detail I took from my build:







Thanks for watching,hope to have helped,

Udo

Udo, would you mind sharing the photos again? It seems they have disappeared. Thanks for the pdf with the colors "translated". I will probably manage with the help of that pdf, but it would be great to double check with your photos.

Greetings, Hans-Olav