API 500 Series DIY??

I have been seaching the forums and noticed that I cant find any API 500 Series DIY type projects. Wouldn't this be a good fomat to construct projects into being that only a face plate would be necessary and not an entire chassis or PSU. I know some things would be impossible to fit in that format howver there are may other companies besides API . . BA, OSA etc that do it. I am kind of new here so mabye this was covered before. But if any one could pint me in the right direction I would really appreciate it.
Thanks,
Joe

At some point you'd have to build a frame and power supply to fit the modules into - they are not self-contained. All of the 312 variants around here do pretty much what you need in a mic pre and the other units in the series are much too complex.

:thumb:

I think maybe joe means any old kind of project, just built to that form factor so you can just use their rack and power supply.

I suggested this a very very long time ago and I think the reason its not popular is because people obviously dont have the racks. Id love to see more projects that could be easily built likt that, the metal work would cost $2 as opposed to $60 for a chasis. But again, not many folks around here have 500 racks.

dave

soundguy, That is exactly what I mean. Even to tweak or add new modules would only be 2 screws. The OSA rack & PSU holds 11 cards for something like $599.00 and the API about the same for 10 slots. I think that is worth it IMO.
Joe

I see. Is a dbx 900 frame compatible? I could find out myself if I wasn't too lazy to climb around on the floor.

It would certainly be nice to package other projects to fit that form factor, but it's obviously a big step in design complexity beyond simple audio circuits. Who does that kind of design?

All you would need to do is standardize the board layouts on the edge connector, and stick to the same board size and it would be a great platform to put projects that run +/-16v on. Very very cost effective. Once you had the dimensions for the boards, you could just route your power and audio to the edge and then drop in any old circuit you wanted and use pcb mount parts for the front panel, easy peasy. If someone here is good at layout and wanted to get the dimensions for the board and housing, I would be happy to send someone an EQ to measure out providing I dont need it at work for a few days. Now is actually a really good time if someone wanted to tackle this, I know Im not using any of my api stuff for the next two weeks.

dave

I would definitely be into 500 series rack projects...

Great idea! I have been wondering this as well as I lurk around the site. I have an OSA rack already so I am game.

Jason

I am already using my lunchbox as a test-bed, currently i have my API553ish passive eq's in it, so I am also very interested. I find cases and power supplies a complete pain in the butt, and a rack system means you only have to worry about the front panel!

ANdy P

well, what projects do you guys propose trying to build up like this? Its gotta fit on a smallish card and its gotta run off of a bipolar power supply. Any suggestions?

dave

Melcor Compressor? I haven't used one or given one a good look but how complex can it be? It's a junior 525 of sorts right?

Also, theoretically you could use two slot spaces for a face but use only one connector. So you could DIY a 55* EQ but use separate switches for frequency and amplitude. Doing away with the concentric switches would make assembly easier and perhaps keep cost down as well. This could also make it easier for additional frequencies to be added or even more Q control. Sure one unit would take 2 spaces. But there's no law against that. Is there? :roll:

What about a Quad Eight AM-10 based preamp? It's bi-polar and will run on 15 to 28 volts.

I'm resurrecting this just to see if anyone has done any work in this department? I'm looking at getting a 500 Rack, just seems like you could really DIY something pretty sweet for it!

Aaron

I´d like to have more info on the series 500 rack itself, I mean, where you plug the boards

:guinness:
Fabio

[quote author="soundguy"]All you would need to do is standardize the board layouts on the edge connector, and stick to the same board size and it would be a great platform to put projects that run +/-16v on. [/quote]

hey dave, if this 500 form factor project was to move forward couldn't we have a max voltage from the power supply and each board be down reg to whatever the project/card needs. sort of like the SCA stuff. i don't know if that is in good form to "borrow" from the SCA stuff, but is that a possiblity?
regards,
grant

I would not worry about the borrowing thing, regulators on each channel have been around for years.. Works great too, gives very good cross talk isolation.
I have been thing of making a 990 op amp based pre for the 500 series as well; problem is the 990 can operate up to +-24 volts which gives it more headroom than +-18 V. So you would have a problem with compatibility with other modules...
No doubt that's why I have not seen it from other companies...

oops! i should read more carefully.
i was thinking that this thread was about building a 500 type DIY lunchbox, but it's actually about utilizing existing 500 lunchboxes with new 500 type DIY card projects. sorry. still, a very interesting idea.
-grant

While not an API format lunch box you could always build eurocard projects into a subrack system and use a single power supply with higher rails and local regs.

I'm planning such a thing right now, although not with a backplane and edge connectors. The way Tim has done the 7th stuff looks very good if you ask me.

I have a number of projects I want to turn into cards that can be fitted into a 3U box.....but its going to take years. The nice thing about the API racks is the price...10 slots are pretty cheap these days but its tough to be limited to 16V...I wonder how Shadow Hills have done the 24V Gama...Pucho?

-Tom

Gentlemen,

I may have just what you're looking for. I'm just finishing up a 500 style rack using original 2520's. The PCB's fit in a standard 5.25 by 19" rack. The power supply card fits as well with external power transformers. The power supply can run 2 bipolar supplies and also has phantom. The mic pre card has front panel mic in, line in, 20dB pad on mic , 12dB pad on line in, phase reverse, and phantom switch. The boards fit JE115 xfrms and either the API or Jensen output transfomers. It also has an 8 segment ajustable LED VU meter. I can fit either 8 mic pres and power supply card or 10 mic pres (with power supply external with toroids). The first mic pre has been tested and works very well. I'm waiting for the first single unit test front panel to make sure everthing fits. Once this is done I can commit the rest of the panels and the backplane PCB design(64 pin DIN connectors) so all modules slide in and mate and fit within the 19". The backplane also allows for rear panel mic connections.

Here's the catch. I've also designed my own discrete amplifier block that fits into the standard footprint. This was quite an undertaking and I should have some results on this item is just a few weeks. If it sounds and specs good (must be better than good!) I may market them. If the opamp doesn't work well.......well then I may just offer up some of these boards if someone is interested. It all hinges on the opamp.

Anyway, as soon as I get the front panels back I'll post some pics of all the pieces. I can tell you that it's not an easy job to get all this to fit in a 1.7" X 4.5" X 6" PCB and put 8 of them in a rack with a regulated power supply along with it.

I'll keep update soon.

Best Regards,
Jeff

[quote author="TomWaterman"]but its tough to be limited to 16V...I wonder how Shadow Hills have done the 24V Gama...[/quote]
Peter was pretty vague when discussing Shadow Hills power requirements at the AES show. If I interpreted him correctly, and I think I did, then it seems their op amp normally runs on +/- 24V, so he put a pair of DC-to-DC converter chips (read: switching supply) on the 500 card to step up the +/-16V. Seems kinda silly to create such a potentially problematic situation for that little bit of headroom if you ask me. Bipolar 16V is plenty if you use it right.

deveng,

API stuff is 1.5" wide, as I'm sure you know. Sounds like your rack is not compatible.

[quote author="TomWaterman"]While not an API format lunch box you could always build eurocard projects into a subrack system and use a single power supply with higher rails and local regs.
[/quote]
The Eurocard-format is nice indeed.
The nice thing is that you can simply use an Eurocard-PCB & just a frontpanel or give it a complete casing, depending on requirements.

The reason I'm using it is more pragmatic though, it's easy to get as surplus here. New stuff does cost some though.