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

GroupDIY Audio Forum

Help Support GroupDIY Audio Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.
lol I know that.  I built two of the older style cases already.  I'm just saying that it seems like the box could've supported a whole slew of awesome modules if it were designed to be able to power 22 modules that use both sets of rails.    It's very confusing to the average person when you read "it can power 11 16V modules and 11 24V modules simultaneously" but see that it only has 1 cable port for providing that power.  Kinda like false advertising, cuz you have to do some serious case and wire modifications to achieve that with the old PSU rack case. 
 
nah.

look, there is a whole big thread about the PSU design, and power consumption, etc.
fine, it is a few years old, newer members won't have read it.

it is not false advertising!

looks like all the basics are gone:

questions like "how many modules can be powered with this PSU" are just funny.
the original PSU is designed to power 12 modules, at each rails maximum.
no module like this is available.

know your modules and power consumption, we don't know what you will put in your rack!
enough scenarios for one PSU powering up 3 cases ...

how would you advertise this?

the basic rule:
if you want to be safe, ONE PSU for EACH Rack.
if you know your modules and requirements, anything else is fine.
 
I have a question for you guys.  I finished my PSU last night.  Killer design Jeff.  Everything seems to be working perfectly, except the phantom power rail.  I am only seeing 22.5 volts on that connector.  I was incredibly careful to check for shorts and bad solder joints as well as double checking all the values of the resistors before putting them in.  I would really love to solve the problem without taking half of this thing appart so any ideas of what could be causing the voltage to be that low?  The only thing I can think of is if I got the regulators switched around somewhere.  I don't have the PSU in front of me right now so I'll have to double check that later. 
 
No.  I was just measuring the PSU unconnected to the actual VPR rack.  Reading through the directions it seemed like that was the way to do it.  Should I be checking it with a mic pre hooked up?
 
Alright problem solved.  I ended up having the power transformer hooked up incorrectly.  For the record for anyone building the dual VPR version of the PSU, the wiring colors match the assembly guide photos exactly except you put the black wires where the white wires are in the photos. 
 
mulletchuck said:
So it will only run 11 modules of one type and also 11 modules of the other type?  But it will NOT run 22 modules that use both sets of rails, correct?  What needs to be changed for it to power 22 modules using both sets of rails simultaneously?

Im just curious,  what modules are you using that uses all the power rails?
 
First post here I think, Peace & Love everybody!

Just started building 51x floor PSU following classic api assembly aid.
I'm in Europe, so I got parts from Volker (thanks!).
I was just connecting  toroid transformer and noticed this in Jeffs instructions:
"The following references to the toroidal transformer connections are all made in
consideration of the US toroids. If you have the European version from Volker or Cemal, please refer to
the correct datasheet for the proper wiring of the primary and secondary leads."
  Is this datasheet somewhere to be found?
Or has this been discussed in forum? I'm sure this info is somewhere, but as everybody know, finding stuff here can be bit difficult... ;)
 
I got mail from Volker about the EU toroid datasheet:

well, there is no EU datasheet - but you don't need one anyway ;-)
only the lead colors are different:

- Primaries: 115V + 115V            [Yel-Wht/Yel-Wht]
- Secondary 1: 2x 24V / 2x2,20A [Red-Grn/Wht-Blu]
- Secondary 2: 2x 16V / 2x2,20A [Ora-Gry/Brn-Vio]
- Secondary 3: 1x 48V /    0,25A [Blk/Blk]
- Cu-Foil Screened                      [Grn Yel]

You can find this same info on the transformer itself but abbreviations are in german, so they can be bit difficult to understand if you don't know the name of colors in german... ;)
 
the description is copy and paste from your invoice ;)

however, the EU version:
- doesn't have the Primary one-shot thermal fuse
- doesn't need the steel mounting dish & foam pads
 
[silent:arts] said:
the description is copy and paste from your invoice ;)

however, the EU version:
- doesn't have the Primary one-shot thermal fuse
- doesn't need the steel mounting dish & foam pads

heh, I was sure this info is somewhere! ;)
I had to check invoice again, you're right but there is nothing about the wire colors!

I was wondering about the mounting dishs and foam pad did the mounting without them. I was also missing the big mounting bolt for transformer, but find replacement from garage... ;)

I almost finnished here, soon we'll see what happens! :O
 
...and it works!
Was great and fun build, thanks Jeff and Volker! (and everybody else involved)
This box looks almost too professional! All my previous DIY are in in nonlabeled steel chassis...
Next I have to build 2 x VP28, They are waiting in box on my table :)
 
So I finished my build and tested some units.  Sounded great.  Fired the PSU up again, only to find out I've lost -16, +16 & +48.  Opened up the unit and come to find out the fuses are on those lines. Any ideas, folks?
 
My first guess would be that a 15-pin 500 series module was plugged into an 18-pin card edge connector and not seated properly. This has happened before and if it does, +16V gets shorted directly to ground while -16V and +48V are shorted together blowing all 3 fuses. I would remove all modules from the rack, replace the 3 fuses and fire up the PSU. It should come back up fine. Next, seat your modules holding them up so you feel the PCB card hitting the inside TOP of the card edge connector before seating them fully.

With the power off, you can use some cut off pieces of plastic wire ties to make some "keys" to help fill in the spot so this does not happen again.
 
HA! You even provided extra fuses as if you knew I would do that. Worked perfectly. Thanks man, I owe you a beer next time I'm up in Chi!
 
The order of the wires on the star ground stud is not important in my opinion. As long as they are all there and making good solid contact it should be fine. The order can be changed if you want but I don't see the need myself.

The #6 screw for the star ground is not "painted" but black zinc coated which in the supplied kit, is conductive. This can easily be verified with a DMM. I have done it. Besides, the nuts and ring connectors are all making contact with each other and then to the heatsink side which has no paint in that area. The screw is just a mechanism to hold them all in place and give a means of tightening them together.

On the build I have here, I get no resistance when measuring DCR between the cross-corner screws from back panel to front panel, one heatsink side to the other. This tells me I have a good solid connection between front, back and both heatsink sides.

One could always add a discrete wire from the top panel to the star ground and bottom panel to the star ground. With my build here, I don't see a need for this but since this is DIY, folks can mod, change and get creative if they have the desire.
 
I hope I did not come off trying to knock your kits.... I in fact am waiting for the VP28 to come back in stock so I can order 2 :) I just simply wanted to see if the items I noticed were just isolated to me or if it was something that all builders might have encountered and not noticed. I have struck out stuff in my original post to avoid future confusion. My apologies if I offended you in any way!

I actually did not know they made screws like that. Pretty cool. I just assumed it was painted and did not bother to check it with the DMM. (I guess that is what I get for assuming...)

Do you have any suggestions as to why the case wouldn't get the same continuity as yours? I have ran all the screws on the chassis 2/3 times in order to try and scrape some paint/powder coat in order to get conductivity. I still only get conductivity from ground on the panel with the star ground. Am I missing something in the instructions or is it time to get some sand paper?

I understand the "to each his own," but I would rather have the IEC ground first because it would be the last to come off if for some act of God the nut came off. That way the case would be grounded until all eyelets were pulled off. I would rather error on the side of safety. (To anyone reading this, it is still perfectly sound to do it the way Jeff describes in the instructions.)
 
No worries and no offense taken.

I am not exactly sure what the dif would be. I did nothing special. I suppose you could take one step at a time like scrap/sand the rear of the back plate to make sure it is making good contact with the heatsink side and so on around the perimeter. It should only take a small area. Check with your probes on the larger screws since they are conductive.

I will add that to my knowledge, the place I buy these customized heatsink parts from does nothing special to insure continuity between their top or bottom panels and the rest of the case. They also have CE and UL approval for all of their PSU's.
 

Latest posts

Back
Top