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

[tyskstil]

Okay, so I have assembled everything, and I have just plugged in the PSU to see what happens. This is an unassembled kit from 2013 that I have bought secondhand.

The IEC illuminated switch is super sketchy, possibly corroded inside or something. I can hardly get it to switch on, and it is loose and inconsistent in the pressure that needs to be applied for it to switch on/off.

I know the new versions have another IEC and thus possibly another switch, buy for the old IEC, can you point me to some specs for the illuminated rocker switch that fits the rest of the IEC so that I can find another one somehow?

UPDATE: Okay I just ordered a switch from Tayda, which appeared to have the wrong dimensions, buy it actually fitted the panel, so the IEC is now fixed!

 

[tyskstil]

I have another question: I have 230V in my country (Denmark).

I installed a 1.5A fuse in the IEC as instructed in the guide (well, 1.25A, but I didnt have one in the kit).  However, it seems the inrush current (?) burns the fuse as I switch on the PSU - I had it work, but shutting off and then on burned the fuse. Happened two times. Now, I installed a 2.5A fuse, and everything works fine - all voltages are as expected.

Is it wrong / dangerous to have a 2.5A fuse installed in a 230V country?

 

[madbeavis]

Hello all,

I am having a strange issue with my CAPI PSU. When running 16v rails everything works fine however when I switch to the 24v rails it will work for around 30 minutes then the (+) rail will go out. Here is the odd part, if I unplug the 24v connector from my console the (+) rail immediately comes back. Another oddity is I get the (+) 24v rail to come back online when the console is still connected if I slap the PSU chassis.

The 24v rails worked without a problem for the past year, this problem started around 3 months ago.

troubleshooting steps performed:

1. Checked all internal connections in the PSU and reset the 24v connections just in case
2. Double checked all fuses
3. Ran PSU unloaded for several hours and 24v rails were fine
4. re-soldered and insulated XLR connectors at the console in case of arching
5. Shouted various profanities at PSU

Steps to repro issue:

1. Connect 24v rails to console and run audio through the channels. After about 30 min the (+) 24v rail light will go out and the console will cut out
   1. un-pluging the 24v KK connector (inside the console) restores the (+) rail immediatly
2. 16v rails do not exhibit this behavior

Any ideas would be appreciated.

Thanks,

Chris

 

[[silent:arts]]

Make sure you have an LM350 regulator for IC3, not the TL783.
Make sure IC3 is properly insulated from the heatsink.

 

[madbeavis]

LM350T regulator on the positive rail and heatsink looks good. I reheated the solder joints in case they were flimsy. It stopped working again around the same time period. I dont think this is heat related because the power is restored immediately when I disconnect the load. I doubt that I am exceeding current capacity but I will figure out a way to test that next.

 

[madbeavis]

well I stand corrected...

Problem was too much load. I have 990 opamps in my summing array and 2 bus (12 opamps total at +200mA max). These alone are probably coming close to the 2.2A ceiling with a busy mix. My channels (32) all have Gar AM10 opamps which are probably not far off from the 990 current draw @24V.

My solution will be to leave the summing amps and 2 bus on the 24v rails and move the channels over to 16v.

 

[madbeavis]

The above statement was taken from other forum posts regarding Max 990 current draw and I think they were mistaken with the 200mA figure. The 990 idle current is 26ma but I never see over 50ma on any stages (tested with my bench supply) even when driving a 1:2 xmfr. My total current displacement is 750mA at idle, upwards of 1.6A with all channels lit up. I am not stressing the supply current at all and I tested for parasitic oscillation in my bus array and 2 bus but found no frequencies over 30k.

After this I started all over....

I setup the PSU with a DMM strapped across (+) and (gnd) and found the voltage was swinging wildly between 5v-26v. The (-) rail was fine however. If I adjusted the cable at the PSU the voltage would briefly stabilize. So I re-cut/stripped the cable and re-sat all the connections making sure to leave plenty of flex room but the problem persisted.

This led me back to investigating the 24v(+) regulator @[silent:arts] mentioned. I noticed that there was no give at all between the heatsink and the board which made me think if there was too much pressure on the solder joints. So I loosened the PCB Chassis screw nearest to the (+) regulator by a turn and the voltage immediately stabilized.

3 days of troubleshooting over a screw.. but hey, still worth it in the end.

 

[jimmyt88]

The two windings are identical, the order doesn't matter (but polarity, sense the yellow / white coding)
If in doubt make four stickers with the colors Jeffs transformer uses: brown, violet, grey and blue.
Take one winding and stick brown to yellow, and violet to white.
Take the other winding and use the grey sticker for yellow, and the blue one for white.
Now you can follow Jeffs wiring instructions using his colors.

This is the answer (comparing the Volker transformer to the Capi) to my search! I've been converting my Capi 51X psu to standard VPR and received all needed parts including the EU version tranny from Volker but really confused about the different colored wires (and, hate to say, a noobie at this). My question now is since this was answering a question about the 230V psu would this sticker method be the same colors for the 115V version psu? I have used mine for years without issues and it has the Capi tranny.

Also, I‘m wiring the rest according to a couple pics I’ve seen but wondering about the L/R orientation of the 2 black wires for 48v…or doesn’t it matter?

Thanks Volker and anyone else who can help confirm this for me.

 

[[silent:arts]]

48V: since it is AC the L/R orientation of the 2 black wires doesn't matter.




For wiring the primaries:
CAPI Brn / Vio is one of the EU Yellow / White pair,
CAPI Gry / Blu is the other EU Yellow / White pair.


For mounting the EU transformer, don't put a nut between the enclosure plate and the PSU transformer.
From the bottom: M6 screw | washer | enclosure bottom plate | transformer | washer | nut.

 

[jimmyt88]

Thank you Volker for the quick reply. So it looks to be the same color-to-color pairing no matter 115V or 230V. Also appreciate the pcb wiring picture!

And I figured out the different toroid mounting once I tried it and realized how solid that rubber bottom pad on the tranny held onto the bottom plate after tightening it down.

I got the 4 resistors swapped so hopefully all will fire up properly and I'll be back in business. Fingers crossed.