Mm. Why not! Microrack!

[Igor]

Thanx. Just check my store 3-4 days later - need to fix some on pricing etc...
www.ij-audio.com/store

 

[Marc Duchesne]

Wow, this would be excellent for my future 51x projects... External power supply for me...
Nice, nice. Can't wait...

 

[dgoszillai]

Hey igor are these available ? can't find it in your website. i have a stereo 12413 waiting at your store maybe i would add this in the same shipping but i need to read little more data to know if i go for this or 51xrack. 

 

[Igor]

So, here we go!

http://www.ij-audio.com/store/50051x/urack/

 

[dogma]

Igor - about to order - but what about the psu? Whats the cheapest way to do it, I mean it would have to be -$30 to make it all worthwhile - and shipping to Australia for a microrack. Totally excellent idea by the way. I;m trying to design a 8 x 2 mixer in this format so perfect for me.

 

[Igor]

Hi Dogma! Thanx).
Try something like JLM power supply.
Toroidal transformer, 50VA, 2x25V AC, LM317/LM337, TL783, +/-24 and +48V output.
Shipping to Australia is included into price. Regular registered airmail, up to 2kg, has more or less same price here for most counties.
BTW, $140 is promo for 10 first kits, and 6 of them were sold at first day.

 

[Igor]

Ahm yep... Or something like this:
(I used these power supply boards with dual or quad Albatross pre's in 2RU).
Parts list - 4x fast 2A diodes, LM317, LM337, pair of 3300x50V low esr caps,
some resistors/ceramic caps/electrolitics/1N4002, heatsinks...
I used to make 6-10 of these boards, so, stuffed board was inside your estimation.
Add 2x25V 50VA toroid and enclosure, done.

 

[dogma]

Ok thanks igor - can you please save one for me microrack for me and I'll send payment.  My email iis [email protected] - cheers, Matt

 

[canidoit]

Will there be a packaged price for both power supply and microrack??

When will the power supply be available??

Is there a complete built power supply out there that can be used and you just have to change the connector??

 

[Igor]

Hm, OK... I will think about power supply in microrack enclosure as well.
But making it from JLM power station etc will be cheaper, I think.

 

[dogma]

Igor the powertststion in 50% roughly more at 60 for the psu (powerstation) - hav a look at the trex kit at $20. Physically much smaller. Psu will be key to microrack success. At the moment it's 140 for metal work for 2 x 500/51x slots. Please incorporate cheap psu

 

[dogma]

If you give. E the exact specs and what to search for (include anything you think relevant) but make it understandable. Ill look for a cheap ready made solution. You've not got anything that would work in this application from all of your previous projects?

 

[gemini86]

Is this what diy has come to? You cannot be bothered to find build a simple psu? Igor has spent A good deal of time and money developing this rack kit, if you need every little thing done for you, I recommend buying fully built commercial gear.

 

[kante1603]

Exactly!

 

[andre tchmil]

Is this what diy has come to? You cannot be bothered to find build a simple psu? Igor has spent A good deal of time and money developing this rack kit, if you need every little thing done for you, I recommend buying fully built commercial gear.

+1

 

[canidoit]

There are different levels of DIY. One in full kit, partial kit, full package, build from schematics, build from nothing, etc.

I am not saying I am not willing to buy a fully commercial product, but with the price of some DIY versus Commercial, it makes it hard to show support to designers with their own products.

If you really want the spirit of true DIY, maybe we should all be creating our posts using markup/code and host our own servers to attach images?? It seems like we all need something to make life easier, cheaper, etc. : )

There's nothing wrong with asking especially if it's feedback about a product.

 

[Ego Tripper]

Canidoit, I think it just becomes bothersome to some members to have to keep answering simple questions whose answers appear in the same thread. However, to those members, these answers were not presented in a straightforward fashion (i.e., all the relevant specs together in one place). In fact, the question of the power supply was initially fraught with heated discussion over it's very type. So I believe one can excuse the uninitiated for not being able to pick the relevant details out of the discussion.

And aside from the fact that working up a simple power supply is, well, simple, in my experience it is often even simpler (and more importantly,) cheaper to purchase a power supply. And then you're not just getting a simple power supply, but a well designed one.

So, with all of this in mind, here's your relevant specs, guys:
Whenever selecting a power supply, you need to find one that can deliver what the gear needs to eat. This piece wants to eat +24V, -24V, and 0V, and it wants it delivered into a 4-pin XLR jack. For current requirements, check the 500/51X spec for a module's max current consumption, multiply it by however many modules you plan on powering (two, if you just plan on powering a single MicroRack), then give yourself a little headroom. I'd imagine the ampacity of the power supplies Igor recommended would be a pretty good ballpark figure from which to work (although, looking now at Igor's site, he provides 80 mA as the minumum, so anything with at least 80 mA will work).

Now, the 0V rail is merely the shared common between the two power supplies (the positive supply's low(-) output & the negative supply's high(+) output). The +24V and -24V can come from a ±24V power supply (which is basically two separate power supplies with a shared common in the same enclosure), or it can come from two separate 24V supplies that have floating outputs so you can wire one supply's positive output to the other supply's negative output (both of which are then wired to case ground). The DC power cable can be attached to the power supply via a simple hardwiring, or can be detachable via a connector (4-pin XLRs are nice). The other end of the cable needs to terminate in a female 4-pin XLR to mate with the gear you're powering. Notice how the XLR gender conventions are reversed for power applications; this is to prevent electrocutions & power outputs getting shorted to ground. 4-pin XLRs are available at most electronics supply houses (e.g. mouser.com). I'm pretty sure 4-conductor shielded cable is available at Home Depot. I'm not sure if you have anything equivalent to Home Depot in Australia, but that should give you an idea how common it is. Actually, without phantom power to transport, you only need three conductors, and one is ground, so you could just use a mic cable.

Knowing this, you can DIY yourself a PSU which provides everything that DIY is all about: affordability, performance, & satisfaction over a job well done. Just go on eBay and look for some used Power One linear* power supplies at 24V. You're lucky, because 24V is a standard output from Power One and you won't have to modify the PSU itself. You will want a fuse in series before each power transformer's primary. The appropriate fuse rating for a given input voltage is helpfully printed on the PSU itself. At this low of a current, you'll be able to find ±24V supplies; the higher current supplies are only available as individual PSUs. You may however find it to be cheaper to buy higher current supplies (which may be in lower demand) provided you can spare the space & watts. The Power One PSUs are way better than most forum members could design and they're usually a cheaper option than building from scratch. What's not to love about that?

* Although it has been established in the related thread spun off from this one that switch-mode power supplies can be applied in a high-quality design without a performance compromise (and with the addition of some benefits), it was also established that they need to be custom designed for audio, which I believe we can all agree is not a task that the average neophyte is able to undertake.

 

[Biasrocks]

You will also need 48 volts for anything that needs phantom power.

On a related note, You guys realize that you can buy a API 6 space box with a power supply for less than what it will cost you to build this one. That's without the hinted at price increase after the first ten are gone. An 11 space box with the proper power supply from GDIY will cost you just a little more than that.

Regards,
Mark

 

[dogma]

Sheez I didn't think asking to assist the designer, manufacturer in trying to source a cheap off the shelf psu - I was tring to help the community as well as help igor.
There are ,any people for whom this rack would be perfect - including me as I need a couple more channels.
I'm very green, don't know the rules or etiquette, obviously I've "offended" some by my noobishness. I'm still going to post on here if I find anything relevant.
So for those that had purchased 6-7 o. The first day - where they going to roll they're own?

 

[Ego Tripper]

Sheez I didn't think asking to assist the designer, manufacturer in trying to source a cheap off the shelf psu - I was tring to help the community as well as help igor.

In this case (and many others), the designer/manufacturer has decided to give purchasers the freedom of choosing their own PSU. This is done for a few reasons, some of which are:
- Cost-- in purchasing the product (especially one with as low of a current draw as this one), you won't also be paying for a PSU you may not need. Which brings me to the next reason, which is...
- Necessity (or lack thereof)-- if you don't need a power supply, it's probably because you already have a ±24V power supply sitting around with 80 mA to spare. And you may have built/bought this PSU based on a strong...
- Preference-- As evidenced earlier in this thread, some people have some strongly held opinions regarding the operating principle of the power supply itself (i.e. linear vs. switch-mode).

I'm very green, don't know the rules or etiquette, obviously I've "offended" some by my noobishness. I'm still going to post on here if I find anything relevant.

The reason why some feathers were ruffled is mainly due to the fact that on information-oriented forums such as this, it is considered bad etiquette to ask questions which can easily be answered by Google-ing. Otherwise, the forum would be choked with threads full of questions that were answered in previous threads.

In this case, the designer/manufacturer had already provided the "exact specs" (i.e. "what to search for") on the product's web page. Taking this info and putting it into Google would have provided many options for ±24V power supplies, from sites like Rod Elliott's which will provide you with a schematic and a complete breakdown of the operational theory behind the circuit, to discussions on this very forum from members in the same position as you are but when the forum was much younger and the question had yet to be asked a million times, to sites selling ready-made PSUs which would put some of the prices you've been seeing into better perspective.

We all have to start somewhere, and I've certainly run across some of my old questions on this forum that seem pretty obvious to me now but which I could not have resolved on my own due to some key fragment of missing knowledge. But in all those cases, I pretty thoroughly searched for the answers on this site and the web as a whole. When you get stumped, we're here for you, but we don't want to hold your hand. For example, if you had done some searching based on the designer/manufacturer's specs, but you weren't finding many affordable audio-appropriate PSUs at 80 mA, it would not have been considered uncouth to ask for further suggestions after outlining your efforts (at that point someone might recommend dropping the current spec from your search terms, as most PSUs have way more than that already, and too much current capacity will not hurt the equipment being powered).

So please, keep posting, but use the search bar first!

There are ,any people for whom this rack would be perfect - including me as I need a couple more channels.

While the need for this eludes me, I think the need is evidenced by the fact that no one has brought up this price-per-module issue before (or asked something like, "Why would anyone want this?").