Standardized Card Edge for All Future 500 & 51x Projects?

Igor said:

Hi Jeff, +1 for the tabs
But, for future, will do all 500 stuff with 18 pin option, to be on safe side twice.
Can you please post exact dimensions for this cut at "pin16"?

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This is what I do Igor. Peter's layout is very, very similar.

Sorry to all of our metric friends.  :'(  I guess this is when 25.4 is our friend! 



Cheers, Jeff

Done....
2.54 is my nightmare
How can you live with these inches!!!!
It is like you come drink beer at local pub and expect to hear Tom Waits at background and instead
of this you have Mondeal GOOOL!!!! No way. I hate inches and Mondeal

jsteiger said:

FWIW, I think the keys would work

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my friend is wrong here
the polarization key was indeed planed from the initial designer (Collin).
I did a long research on them once I took over the PCB design.
a) they are nearly impossible to buy
b) with a full pin key in at 16 a 15pin module won't fit anymore
look at your 15pin card edges, top and bottom are wider than the distance between the pins

Igor, you are right. and the main pain for a nice looking PCB layout is the 2.54 and 3.96 mixture ;D

I did briefly look last night. The polarization keys for the old Cinch connectors do not quite fit the new ones we use. The keys fit inside a small rib that is between the actual contacts. If the key is put between 16 and 17, it would work, not between 15 and 16.

I will inquire if I can even get them. Maybe just for fun

Best, Jeff

can't find the postings where this was discussed before, but I found this on my server already:

I am checking to see about the keys for "in between contacts". If they are available, we will see how much they are. I know the old Cinch ones were ridiculous in price.

It should be noted that the CAD drawing I posted, was not intended to accept the polarization keys. It would have to be modified a little bit.

jsteiger said:

... It should be noted that the CAD drawing I posted, was not intended to accept the polarization keys. It would have to be modified a little bit.

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with only 4 (to my knowledge) 18pin PCBs designed yet this shouldn't be a problem
find them ;D

BTW, let's do something compatible for easy adjustment
of modules outside of the rack.
It can be extender or dummy panel with XLR's.
Like this....

A kinda testing desk...

I have always used a piece of large nylon tiewrap as a connector key.  Very durable, and they are all over the studios.  I cut it slightly larger than the connector width, and it stays in tight.
DIY baby!

sodderboy said:

I have always used a piece of large nylon tiewrap as a connector key. 

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Brilliant!  It really works well???

jsteiger said:

Igor said:

Hi Jeff, +1 for the tabs
But, for future, will do all 500 stuff with 18 pin option, to be on safe side twice.
Can you please post exact dimensions for this cut at "pin16"?

Click to expand...

This is what I do Igor. Peter's layout is very, very similar.

Sorry to all of our metric friends.  :'(  I guess this is when 25.4 is our friend!  



Cheers, Jeff

Click to expand...

Is this still the "standard"?  How wide is a standard 51X board?
Thanks!
Best,
Bruno2000

bruno2000 said:

Is this still the "standard"?  How wide is a standard 51X board?
Thanks!
Best,
Bruno2000

Click to expand...

Bruno2000, the VPR spec says 5.938” +/-.02”. That is from the back of the 1/8" faceplate to the far edge of the gold fingers. I go 5.92" myself. I also deduct .05" off of the PCB for the aluminum L-Bracket.

best, Jeff

jsteiger said:

bruno2000 said:

Is this still the "standard"?  How wide is a standard 51X board?
Thanks!
Best,
Bruno2000

Click to expand...

Bruno2000, the VPR spec says 5.938” +/-.02”. That is from the back of the 1/8" faceplate to the far edge of the gold fingers. I go 5.92" myself. I also deduct .05" off of the PCB for the aluminum L-Bracket.

best, Jeff

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Another question, please:  What are the dimensions of the front panel in relation to the circuit board?  i.e.  Where does the circuit board intersect the front panel  1/4" in from the left?
Thanks!
Best,
Bruno2000

bruno2000 said:

Another question, please:  What are the dimensions of the front panel in relation to the circuit board?  i.e.  Where does the circuit board intersect the front panel  1/4" in from the left?
Thanks!
Best,
Bruno2000

Click to expand...

I uploaded the dim's to the group email account awhile ago. I think there may be 2 sets in the actually. Search "VPR spec" and you should find them.

best, Jeff

jsteiger said:

bruno2000 said:

Another question, please:  What are the dimensions of the front panel in relation to the circuit board?  i.e.  Where does the circuit board intersect the front panel  1/4" in from the left?
Thanks!
Best,
Bruno2000

Click to expand...

I uploaded the dim's to the group email account awhile ago. I think there may be 2 sets in the actually. Search "VPR spec" and you should find them.

best, Jeff

Click to expand...

Got the info, thanks!

I want to design / build some projects in the new 51X format
Now, I like to use relays in my projects for several reasons, and in all of my previous projects, the relays had their own isolated power supply.  There is no provision for a relay supply in the 51X.  My question is, would there be an advantage to power the relays and their associated LEDs across the +/- 16V rails (24V relays with the appropriate dropping resistor or regulator) thereby keeping the power draw of the card balanced (given that the opamp circuits power draw is already balanced) ?  The relays draw about 10mA each plus about 5mA for the LEDs.  I am also powering a 14 segment LED meter and a 3915 driver.  The circuit that I'm using includes a 78L05 regulator for the LEDs, and the 3915 runs on 15VDC.  Obviously the current will vary from about 8mA (no LEDs) to about 100mA (all LEDs on), so a dropping resistor won't work for the meter circuit power needs.  Do you think there will be a problem with noise or other issues with hanging a 7815 across the audio rails?  What I'm also considering is hanging a 7824 across the rails for the relays and their associated LEDs, then powering the 7815 (for the 3915, and the 78L05) off of the 24V regulator so the 7815 wouldn't have such a severe voltage drop across it.  My fear is putting noise from all of the 78XX regs on the audio rails.  Should I worry about this, or is it not an issue with severe filtering?  Or would a LM317 circuit put less "noise" on the power rails?  Another question;  since everything if floating, is there any advantage to using a negative regulator (7924, LM337 etc..)?
Thanks!

Best,
Bruno2000

Bump!

The LM3915 datasheet says "Operates with single supply of 3V to 25V."

You know what I'd do Bruno?  Switch from 12v to 24v relays, and use the +24 supply for relays and LED meter driver.
Then the +/- 16 is freely available for the audio circuit.

Or are you already using the 24v for audio?

jsteiger said:

I go 5.92" myself. I also deduct .05" off of the PCB for the aluminum L-Bracket.

Click to expand...

Thanks Jeff, this kind of real world advice is helpful. I had already designed a card with a depth of 5.938. I didn't even think of the position of one leg of the L-bracket between the card and front panel. Or leaving that extra .018" space, just for wiggle room I guess? or to account for the right angle curve of the bracket

Any advice on where to place the L-bracket mounting holes?  Should we standardize on this too, since we're on the cusp on a new diy audio frontier here. Or just have everyone drill as they may. I envision one day we may have L-brackets and enclosures pre-drilled to 51x specifications.  

----edit---
whew, that was a bitch to layout. but it's done.

kato said:

The LM3915 datasheet says "Operates with single supply of 3V to 25V."

You know what I'd do Bruno?  Switch from 12v to 24v relays, and use the +24 supply for relays and LED meter driver.
Then the +/- 16 is freely available for the audio circuit.

Or are you already using the 24v for audio?

Click to expand...

If I use the +24V for relays and LEDs, then the +/- 24V rails have an unbalanced load, however, the 51X Neve clones use the +24 rail only, thus unbalancing it anyway, and making for significant ground current.  Maybe I should use the -24V rail for the relays and LEDs.  Maybe it doesn't really matter.
Thanks for your thoughts!
Best,
Bruno2000