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

[rachansky]

Glad to hear somebody's busy! I'm pretty much sitting around playing with myself and the chafingbis getting out of hand.

 

[rachansky]

Think I made a booboo....

Made an impulse purchase of the igs audio tube core without looking closely at the power requirements. This thing needs 800mA over 2 slots (400 mA/slot)

Anyway I read about 15 pages of this thread and I'm guessing I only have about 1.5 amps using the dual vpr floorbox power supply. (Please confirm for me!)

My question is, should I begin to draw too much current on my rack what are the expected consequences? Just blown fuses or could there be damage to modules and/or the rack as well? (My racks are both filtered.)

Thanks.

 

[jsteiger]

It should be just blown fuses. There should be no damage to any modules, rack or PSU.

 

[rachansky]

Thanks boss!

 

[curranm]

I have set the voltages for all the IC's in the PUS on my bench before I installed any modules or plugged in the racks. I have blown the phantom power fuse twice now in my PSU. I have two of the VPR racks with 6 modules in each one. 6 of the element preamps, and 6 of the VP25's. the fuse popped on 1st power up with modules in it, I replaced it thinking I had shorted the 48v with my probe when I was testing voltages on the card slots for voltages on 1st power up. I replaced the 48v fuse and everything has been fine for a week. I added the 2nd rack and moved the modules around and POOF, I popped the 48v fuse again. Am i goofing up and a power on sequence or should I not have the Phantom power engaged on the modules OR is there a limit to the number of modules I should phantom power at one time? my understanding is that these should NOT have this issue. all my voltages are set per the build docs, and everything has been working fine for the last week, I just added the 2nd rack to the  mix.

 

[jsteiger]

I have set the voltages for all the IC's in the PUS on my bench before I installed any modules or plugged in the racks. I have blown the phantom power fuse twice now in my PSU. I have two of the VPR racks with 6 modules in each one. 6 of the element preamps, and 6 of the VP25's. the fuse popped on 1st power up with modules in it, I replaced it thinking I had shorted the 48v with my probe when I was testing voltages on the card slots for voltages on 1st power up. I replaced the 48v fuse and everything has been fine for a week. I added the 2nd rack and moved the modules around and POOF, I popped the 48v fuse again. Am i goofing up and a power on sequence or should I not have the Phantom power engaged on the modules OR is there a limit to the number of modules I should phantom power at one time? my understanding is that these should NOT have this issue. all my voltages are set per the build docs, and everything has been working fine for the last week, I just added the 2nd rack to the  mix.

As discussed via email, if you are using our filtered racks with a Floor Box PSU, you need to change the 160mA fast blow to a slow blow. The inrush current required to charge the rack's filter caps is enough to trip the fast blow fuse.

 

[New Soul Rebel]

Hello Guys
I moved into my new apartment, and I can't believe it. First time I fired up my two Capi Racks, powered by one dual floor PSU and i have no phantom power. I have changed the fuse for two new 160mA fuses in a row, and I am getting zip. nothing reading on the 48v rails and obviously no LED.
Can someone point me to some checks so I can eliminate what is either shorting or blown.
I have had 5 years of flawless operation with this PSU until I left my wife. I got my gear back off her at the beginning of the year and it had to go straight into storage.
To be clear, I have power to the 16 and 24 rails and no issues with running preamps in 16v, with DI. Perfectly good guitar signals, just no life on the 48v rails.
ANY help on checks would be appreciated. Cheers
Matt

 

[[silent:arts]]

Check your Voltage before the fuse.
Check your Voltage before the 48V regulator.
Check your 48V AC voltage at the PSU transformer.

 

[New Soul Rebel]

Check your Voltage before the fuse.
Check your Voltage before the 48V regulator.
Check your 48V AC voltage at the PSU transformer.

Volker, do you mind if I ask you a question. I have pulled the PCB on this PSU so that I can get easier access for testing.

But the 48v regulator still has charge going to it, even when the board is removed and disconnected from the toroidal. Around 23 volts dc. How do I safely discharge it, so that I can work on it as the reg looks damaged and needs replacing i think

I have the same voltage at

Matt

 

[[silent:arts]]

The caps should be empty and safe now 

 

[New Soul Rebel]

The caps should be empty and safe now 

It isn't! It still has around 20 volts!

 

[[silent:arts]]

It isn't! It still has around 20 volts!

After such a long time?
Is your Voltmeter fine? (Batteries?)
However, 20V won‘t kill you.
If worried just short the two 100V caps to ground.

 

[New Soul Rebel]

However, 20V won‘t kill you.

That's reassuring.

 

[New Soul Rebel]

Volker, do you mind if I ask you a question. I have pulled the PCB on this PSU so that I can get easier access for testing.

But the 48v regulator still has charge going to it, even when the board is removed and disconnected from the toroidal. Around 23 volts dc. How do I safely discharge it, so that I can work on it as the reg looks damaged and needs replacing i think

I have the same voltage at

Matt

Volker, I never did work out why I was still getting pokey voltage readings at the reg. In the end, I carefully desoldered it, replaced it and problem solved. Somewhere along the line I shorted this thing when I was testing it and I think this is what caused the problem in the first place. Anyway, problem solved.

 

[Teej]

Which fuse is correct for F1 (48V)? It calls for 160mA 250V FB, but what's the diameter?

Thanks!

 

[[silent:arts]]

5 x 20 mm

 

[Teej]

5 x 20 mm

Thank you!

 

[tyskstil]

I am building an old PSU floor box kit from 2013, with a european toroid. For the EU toroid, there is a plastic cylinder molded to the inside, which rests on the nut on the inside of the bottom plate. This makes the toroid float approximately 1cm above the floor. Is this correct? There are no steel mounting dish & foam pads, which makes sense it if floats, but I am still doubting that I mount it correctly.

From the bottom: Bolt, washer, plate, washer, nut, toroid, nut. Correct?

Additionally there was no long M6 bolt in the kit. I saw someone else in this thread with the same experience, but I had one spare from another toroid that I could use. But it leaves me with a feeling I misunderstanding completely how to mount the EU toroid.

Any thoughts?

 

[[silent:arts]]

From the bottom: Bolt, washer, plate, washer, nut, toroid, nut. Correct?

No. Correct is:
Bolt, washer, plate, transformer, washer, nut.

 

[tyskstil]

No. Correct is:
Bolt, washer, plate, transformer, washer, nut.

Fantastic - that makes much more sense. Thanks!