GroupdDIY 511 Racks: round 5.5 available

[kante1603]

511 Kits are available to France ...
send an email to kitorder @ 51xAudio.com

oooops.....nearly double posted....
Wanted to suggest the same because it's to france,therefore to ask Volker,hahaha......

Cheers,

Udo.

 

[daal]

Thanks !! I thought it was off for sometimes so I was asking now, thinking I was ahead of a new batch. I might have to wait some weeks because I don't have the money yet (or have I ? I'll crush the numbers until I got it I guess ) I really hope to send this mail in a few days / weeks though!!

 

[daal]

There's a god of DIY. I just received an unexpected amount of money during the night (yes it's true !!!). Mail sent

 

[kante1603]

There's a god of DIY. I just received an unexpected amount of money during the night (yes it's true !!!). Mail sent

Cool,but be warned,once started diy you might not be able to stop anymore.... ;D

 

[daal]

I know, I just built 4 preamps from Soundskulptor and am starting a SB4000 build those days, and I want more already

 

[jsteiger]

I have finally gotten around to adding the GDIY 11-space rack kits to my store. So, North American customers can checkout automatically. Here is the link. http://classicapi.com/catalog/index.php?cPath=87_89_182

 

[atticmike]

never mind

 

[bacbacou]

hello  !

It is my first message here so I hope I am in the good thread for my request.

I just bought and start to build my 51xrack, but I have a problem :

All the XLR plugs have a chassis to pin 1 connexion, and I solder them like that, because it is the right way and the PCB is made for that. But in this case, the "chassis/pin1/ground" jumper does nothing !

In this case, it is impossible to disconnect chassis (witch must be connect to earth ground for security reasons) and electrical ground !!!

No so important, ok, but If there some background noise problem / ground loop with a module, it will be impossible to solve it like it have to be with a ground lift switch or jumper...

Could you confirm ?

regards,

Richard

 

[kante1603]

All the XLR plugs have a chassis to pin 1 connexion, and I solder them like that, because it is the right way and the PCB is made for that. But in this case, the "chassis/pin1/ground" jumper does nothing !

Hello Richard,welcome to the forum.

I'm not sure if I get you right.How did you find out that the jumper does nothing?
If built correct you should have the choice to make ground connections-which is a big advantage in this rack.Wether you can connect Pin 1 on the XLRs to chassis ground,to 0v or leave it open.
Did you measure these points and if so,how did you do it (e.g. With psu attached or other gear).

Best regards,

Udo.

 

[bacbacou]

hello Udo,

all the XLR plugs have pin1 link to chassis.

"How did you find out that the jumper does nothing?"

Simply by testing with my ohm meter  !

all the XLR plugs have pin1 link to chassis, so even if you put your jumper in "pin1/ground" connection, you have the chassis connected to pin1 too... so in this case it is impossible to use the jumper as a ground lift.

"Wether you can connect Pin 1 on the XLRs to chassis ground,to 0v or leave it open."

No, you cannot because Pin1 is ALWAYS connected to chassis...

regards,

Richard

 

[kante1603]

hello Udo,

all the XLR plugs have pin1 link to chassis.

"How did you find out that the jumper does nothing?"

Simply by testing with my ohm meter  !

all the XLR plugs have pin1 link to chassis, so even if you put your jumper in "pin1/ground" connection, you have the chassis connected to pin1 too... so in this case it is impossible to use the jumper as a ground lift.

"Wether you can connect Pin 1 on the XLRs to chassis ground,to 0v or leave it open."

No, you cannot because Pin1 is ALWAYS connected to chassis...

regards,

Richard

O.K. Richard,

I measured an unconnected 511x rack some minutes ago.Here's what I found.Pin1 on the female xlr connectors really connect to chassis ground,but at around 0,7 ohms on my Fluke.
There's no connection between chassis and pin1 on the male connector.
Then,for my reference,I measured the chassis to the chassis point on the psu connector.I now have a reading of 0,1ohms which is quite perfect.After some thinking I thought it must be the female connector by itself and voila:I'm right!
Btw,there's no continuity between chassis and the corresponding header pin1.
So I looked on the Neutrik homepage for exactly this female connector and found this for NC3FBV1:

Pin 1 connected direct to front panel and connector shell, no separate ground contact

So everything seems o.k.,it's by design ( hierarchical ground?).
You can do a test when jumpering to chassis,the resistance will go down a bit when measuring between pin1 and the chassis.

Hope to have helped,

Udo.

 

[bacbacou]

thank you UDO.

I will finish the rack and make some test to see.

regards,

Richard

 

[kante1603]

You're welcome.
I have done a few different modules as well as two 51x racks now and never had any issues with them ( knock on wood ;D).
My default jumpers are always pin1 to chassis,a good way to start with.

Cheers,

Udo.

 

[mulletchuck]

Ok, i ran into a weird situation with my 2nd rack.    In one of the slots, i've had two separate modules blow a cap.  the cap that was blown was the output cap for the DOA in both the VP26 and VP312 preamps.  Jeff said that this cap could only blow if there was a big DC offset coming out of the op amp.    Since this only happened in this one slot out of all others in the rack, what could cause the DC offset to occur?    I checked the power rails for that slot with modules in the adjacent slots, and all DC voltages were correct.  Continuity checks also showed that all chassis and gnd connections were fine.  I don't want to have another of these caps explode again because of something i'm missing. 

 

[john12ax7]

Doesn't the VP312 omit the cap on the output?

 

[mulletchuck]

no its there.  it's right before the phase switch in the schematic.  the 470uF 16V cap.

 

[jsteiger]

The VP312 does not have the coupling cap. The VP312DI does have the cap.

Chuck, I don't really see how a PSU problem could be isolated to one rack slot unless there is some sort of install problem with the card edge connector. The other thing would be the install of the module. Maybe it was not aligned properly. You could test/measure the pins with your DMM but be careful when poking around so you don't short anything with your probes.

 

[mulletchuck]

I'll keep an eye/ear on the cap and we'll see what happens.

 

[jimkeaney]

Awesome kits. Built my 2nd one! Now looking at all these new empty slots is depressing me

 

[[silent:arts]]

ATTENTION PLEASE:

Just received an email from my internet provider:

they took 51xAudio.com offline since it has been hacked and was used for DOS attacks.

This means I haven't received any emails / can't respond etc since yesterday.

Will let you know once this is solved ...