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

jsteiger · Jul 4, 2010

Hey guys,

I had a thought after seeing some of the newer projects coming out these days like the Mixbuzz500, EQP500 and Mike's 312. While this is not a necessity, it would make for seating the modules easier in a 51x rack.

I think that all 500 sized PCB's should have the notch and PCB for the full 18 pin card edge connector even if you are not utilizing the 24V rails. Just run out the board there and don't put any gold-finger pads on it. This will make aligning/seating the modules in a 51x a little bit easier.

If a person only has a standard VPR rack (shame, shame ;D ), a simple snip or hack-saw cut and you are in business. No harm done.

I will do this for all of my future projects. Just an idea. Tell me to piss-off if you want.

Cheers, Jeff

strangeandbouncy · Jul 4, 2010

sounds like good old-fashioned common sense to me . . . . !

gemini86 · Jul 4, 2010

not to highjack, has anybody made a module for this card edge in KiCAD?

mikefatom · Jul 4, 2010

Great thinking Jeff! I just added 24V support to my 500 series 312; will test that out when the next proto boards come in.

I also already have it set up for an EQ I'm working on. ;D

Cheers

Mike

jsteiger · Jul 4, 2010

Cool Mike.

Pier's DOA's do sound great in a 312. Currently the best 24V choice IMHO.

Even without using the rails, I just think it makes sense to have that profile. Pretty soon, more folks around here will have 51x racks than standard VPR racks anyhow.

AudioGimmer · Jul 5, 2010

Sounds like a good plan.

Perhaps I could throw out a suggestion too:

Would a card extender [ to allow for testing and adjustment of modules ] be a good idea, given all the projects based on the 500/51x format.
Simple point to point PCB with 500-51x socket on the end, or a ribbon cable to the socket.

This would allow for trims to be adjusted, with signal in/out power etc all derived from the rack?

AG

ioaudio · Jul 5, 2010

jsteiger said:
This will make aligning/seating the modules in a 51x a little bit easier.

hi jeff,

i didnt know that there are problems fitting "normal" 500 series modules, so no notch was implemented in my eqp500.
is there another solution?

-max

[silent:arts] · Jul 5, 2010

Jeff, nice idea

Max, I don't see any problem fitting "normal" 500 series modules in a 18 slot 511 rack - if the metal work is done correctly (L-bracket and frontpanel).

however, since it is DIY here: if the card edge isn't aligned correctly with the metal work:
worst case would be +48V on the -16V rail ...

[silent:arts] · Jul 5, 2010

AudioGimmer said:
Would a card extender [ to allow for testing and adjustment of modules ] be a good idea, given all the projects based on the 500/51x format.
Simple point to point PCB with 500-51x socket on the end, or a ribbon cable to the socket.

This would allow for trims to be adjusted, with signal in/out power etc all derived from the rack?

would be nice to have something like this.
a PCB solution would need a vertical mounted card edge connector - does this exist?
one other solution I thought about would be a "baby" backplane. only two slots (needed for stereo modules),
it could even include 18pin / 15pin connectors next to each other ...

ioaudio · Jul 5, 2010

thanks volker, now i understand whats the issue - a 15 pin pcb has it´s lower edge "in the air" or floating when placed into the 18 pin socket.
i think a better solution would be a small piece of pcb or whatever inserted into the unused pins, no?

[silent:arts] · Jul 5, 2010

Max, there are different solutions:
- you can use 15pin card edge connectors for the slots where you know you won't have 24pins (not easy to change later)
- you can put in a small piece of PCB (like you suggested, and Jeff showed in another thread before)
- just don't hot-swap a 15pin modules in a 24pin chassis

as said before, I don't see any problems with well build modules (what I have here actually is from ClassicAPI, fivefish studios, LazPro and Brent Averill. all well build, and once screwed I can't see any chance for any problem.

however, for future projects I think it is fine to just need to do "the cut" for 15pins.
easy to do, safer for all people who want to hot-swap modules.
diodes for the power rails help too.

ioaudio · Jul 5, 2010

i´m not sure about that. immo the solution should be on the edge connector socket´s end.
even if it´s a shame (

): what if someone uses a lunchbox, cuts off the additional fingers but wants to upgrade to a 51x frame in the future.

mitsos · Jul 5, 2010

I agree with Max. I think it would be safest to make some little tabs and sell them with the 18pin connectors/racks, with instructions on how to use them. That makes the rack 100% safe for the rest of the lunchbox world (would remove your liabilty for someone's 525 getting torched if they choose to hot swap without tabs installed), and not just DIY modules that might be made with the extra (unused) tabs on the edge connector.

jsteiger · Jul 5, 2010

I'm not saying it is a requirement or anything. It just seemed to be a potential easy way to make it fool-proof for a 51x owner. If done before the last board revisions, it costs nothing to do so no big deal. The cut-off piece could always be saved to use a spacer to be inserted into the card edge connector. The rack must be powered down to remove those spacers.

The modules for sure will not move once screwed into place.

I have seated standard 15 pin cards into the 18 pin connectors many times now with no problems. Just got to be careful. Maybe some guys are not as mechanical or careful? I don't know. I have not heard of any problems. Only trying to be preventative with future projects. All of the older modules out there have to be dealt with using a spacer in the connector anyhow.

best, Jeff

mitsos · Jul 5, 2010

jsteiger said:
All of the older modules out there have to be dealt with using a spacer in the connector anyhow.

You mean DIY modules? I think it's commercially wise to make these racks safe for all the "industry standard" modules out there. That's why it makes sense to me for the racks to come with a small PCB tab, even though this may be a non-issue for most people with steady hands.

Denyle Guitars · Jul 5, 2010

My first thought was to key the connector @ pin 16. That way there's no chance of misseating a 15 pin module. I suppose that would require a big connector order. More importantly, is misseating even a word? It should be.

mikefatom · Jul 5, 2010

^
|___ +1!

I was actually under the impression that this was already the case for the 51X connectors. When I started researching the format a bit more, I realized that pin 16 was not a keying tab but a regular ol' connection. No biggie really, but that would certainly solve that issue.

Igor · Jul 5, 2010

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"?

jsteiger · Jul 5, 2010

I have the polarization keys in almost all of the edge connectors in my console. API always use to have a notch somewhere. I have looked and the current manufacturer we are buying from (51x racks) does not have the little keys. I really didn't look any farther. I would guess that Cinch or EDAC has them.

The notch that I use, is a little bit different than one for a polarization key. I just checked Peter's EQN boards. His notch and my notch are nearly identical. Kinda weird since we never really talked about it!

Anyhow, my thought, which was inspired by Peter's, was that once you cut away the 17th and 18th pins, you are left with a perfect 15 pin card edge.

Anyhow, let me dimension a CAD drawing and I will post it.

FWIW, I think the keys would work. I will check one out from my board.

Best, Jeff

Curran · Jul 5, 2010

getting the diy action on this amazing board to a standard for the 51x series stuff is a great idea!! you got my vote!!!

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

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