Hi Guys,

Well I have racked probably 20 API modules and a slew of others including Ward Beck, Neve, ADM and now some McCurdy.

I always get asked how to do them if you don't have metal tools, or electronic skills. Because it is COLD in Chicago (and I did not want to work in the garage), I want to try and build a nice rack with just hand tools that everyone has around the house. I did not go out and buy anything for this. This is all from scraps around the house.

Ok so, first I built a wooden box that was the right size for 6 modules. Normally this would be a metal rack, but not everyone has metal tools. When I do build them from wood, I usually use metal rails to mount the modules, but to keep on a theme, I used wood. Take a look. This is just 13 ply ply-wood which is used for building speaker cabs.



Also in a normal situation, you would not make the modules removeable per sei. But I wanted to experiment with a bunch of modules so I added a backplane with 15pin sockets. These modules will be able to come out and others placed in just like a 500 series rack. Normally you would just run a wire harness to each modules with out the cage in the back. Look inside you will see the holes drilled for the next set of connectors.

Here is another look.



This has not been wired yet. You should be able to see the wood ledge I screw the modules to. Normally this would be a peice of angle iron tapped to fit the right screw. Again to make this easy for everyone who wants to try, I used wood.

Ok, YOu should beable to see, I did use some aluminum angle iron (wont bend) to make a connector cage in the back. This was to make it truely moduler.

Its hard to tell, but the modules are resessed so the face of the module is about 1/16th behind the lip of the front.

I have very low feet on the bottom. This was finished with minwax stain and a satin finish. Not to shiny, but looks ok too.

The back is a piece of Stainless Steel I have around the house. It was cut with tin snips and cleaned up with a file. Holes were layed out and drilled for the 6 I/O's and power connections.

I almost always use an external power supply. I did rack some API with an internal power supply, but the metal rack I made was deep and I was able to isolate it from the amps. This one will have an external supply that will sit on the floor behind the rack.

Take a lookL

I hope it was ok to do ths in seperate posts. I don't need the extra posts, but it is easier to do it this way.

I will probably paint the back black and label with a P-touch. This one just needs to be wired. I bought some compressor that will fit in here and they are on the way. They should have the extra connectors for the back.

If you guys are buying modules to rack, always ask for the connectors. While they are only a few dollars, they make is much easier to get started. I made this one 6 spaces, even thought I have 4 modules. The guy I bought the modules from has more, and has others on hold for me. This makes the unit real versital, just like a store bought lunch box.

Let me know if you have questions. I would be more than happy to help you guys out. I can also post at some point, how I racked some API 312 modules in regular rack mount boxes if someone is interested.

JD

Hi JD

Looks good, thanks for sharing.

Peter

That's really cool! Do you build your psu's or do you use the external one API makes? I know you said you mostly used materials you already had around the house for this one but can you estimate how much materials would cost for something like that?

The API lunch box is free from a lot of places if you buy four of their modules but this seems really cool because you could put a variety of different brands of module in one box.

Thanks for posting Jacl.

You can find a ton of power supplies on Ebay for real cheap. I will use one from ebay on this one too. The McCurdy Consoles used to be +/- 25 volt bipolar suplied. Most of thier modules if not all ran with only +/- 18 volts and have regulators as the first thing the power hits on the board. So I found a +/- 18vd supply to use. Coincidentally, API can run on +/- 18v too. And they also use the same 15 pin connector (different size card). I would have to look at my notes to determine if they use the same pins or not. But what this means is, that I could (and am thinking about) Racking a API 312 card onto a McCurdy cardframe and using this rack for a pair of pres too.

They guy I bought the compressor from does have some McCurdy Mic cards which I might buy because they would be plug and play. But from what I have read, the McCurdy pre cards only have an input transformer where as the API has input and output. Alot of the tone of an API is from the transformers.


Ok, so if I had to buy the supplies to build this one it would be pretty cheap as you see it.

For wood you need 2 pc x 9x12 and 2pc 9x7. If you bought a pine 1x12 board you would need only a four foot board. Menards has cutoffs for $1.69. The wood rails to mount the modules to, are from the cutoffs.

Manards and Homedepot sell alluminun angle that I used (.5 x .75)for about $3 for 4 foot. I used about 18". And they sell sheet metal for less than that for a piece big enough for two.

So for raw materials you could do this or a bigger or smaller rack for about 10 bucks!

The 15 pin connectors (if they did not come with the cards) are about $3 each and the 1/4" stereo (balanced) jacks are a dollar or two each. So you could have 30 dollars or more into the electronics. The power supplies are usually less than $25 on ebay ( I paid $5 each for mine).

So I guess if you had to buy everything you would be in the $60-75 range for the rack. Most of the time the cards come with the connectors. Everytime I throw gear out that is not worth fixing, I take all the jacks out, transformers, power supplies, screws sometimes even the case. I rarely have to buy anything but the cards. When I rack API's, I buy a 2U (space) chassis which can cost $30-50. I do this so they rack nice, and look nice with other gear in my racks.

Modules: Well they can be cheap or expenisive. I bought the McCurdy Eq's for $45 for the pair from one guy, and the Compressors for $200 for the pair from a different guy. Those are great prices. Compressors are expensive, so at $100 each that was a steal (plus shipping). McCurdy modules are still reasonable. Wardbeck are getting expensive. ADM, API and NEVE are stupid high. Bang for the buck is stil API 312 and 325 cards.

Right now a rack full of eqs could be very reasonable. Thats what I started out wanting was more EQ's. Regularly you can buy McCurdy Eqs for under $100 a pair! Ward Becks around $150 a pair.

A rack full of compressor would be very expensive. Think of the api compressors at $1000 each, ADM at $500 each, Neve's at$#$%^ so compressors are expensive. But than again how many compressor of one type do you really need?

Mic Pre cards are all over the place price wise. I see spectra sonic 101 for $25-35 per raw card, API's raw 312 for $300 and Neve 1272 for $600. Cards with actual faceplates are from McCurdy $50 to wardbeck $100 to ADM $200 and up.

JD

2 JD
Thank you! This IS the solution for small home project studio. Among other advantages you mentioned, it looks very "warm", just for home so my wife won't get me out of place with all my "tin boxes"! ))

Those are very cool! Very clean and neat...

I really dig that look! But a few questions, if you don't mind...

- How are you getting around the differing power supply needs (I know API/OSA/500 style cards need a different supply that 1081/1073/Neve clones...) Different taps, or a couple of different supplies running to a single enclosure?

- Noticed you use TRS on the IO jacks...is there a specific reason you chose these over XLR?

- Any special shielding/grounding techniques for the aluminum backplate?

Man...that's some great looking stuff there....I wish I had better assembly, solder, and patience skills....there has GOT to be a certain sense of pride in customizing your enclosure gear...

Wireline, Great questions!

Ok, first power. You are correct that Neves use a single +24v supply while, most opamp based units (API/OSA/McCurdy/ uses bipolar (+/-) supplies. If you are going to intermix modules things can be tough to arrange, but not impossible. If I were to intermix, I would mix units with simular requirements.

For example: The McCurdy Eqs and Compressors I have can run on +/- 18vdc (bipolar). So can API and all the incarnations. So while the cards physical size is different, the power requirements are the same. You would simply wire each connector to its appropriate pinouts. So if I added API preamps to this rack, I would just change which pins I run power and i/o's to. The other thing is that the modules are physically different sizes. You can make your box accept different sizes or make adapters to make the adjustments. A good example of this is Brent Averill. He took a API 312 card, and mounted it to a 512 size metal work. Then rewired the card to work with the 512's connections. When I do this conversion, I actually make a card that looks like the larger format. Then I make a socket for the smaller card to plug into. What this does is make it plug and play. You basically make an adapter that does not distroy the orignal card, unlike Brent!

The box above was made just for McCurdy gear in mind, but with an adapter, I could use it with any +/- 18v unit.

In fact, McCurdy really can run on +/- 25v. Each card has a voltage regulator circuit that reduces the voltage to 18v. If you run a power supply with +/- 25v, you can run one leg off of that to power Neve gear. You just need to make sure you have enough current to drive all the modules you want.

I rarely mix manufactures, but I have in a few cases to get an API preamp and another MFG eqs. It might just be easier to make seperate racks.

I/O's: Well, I choose TRS for one reason. My patch bays are all TRS and I do not want a bunch of different cables to patch gear together. So my tape decks run to a TRS patch bay, and are normalled through to my console. I can break that path with patch cables and insert a comp, or eq or what ever. My console does have inserts, but they are unbalanced. I prefer the tone and how quite ballanced is. So this box was designed for Eqs and Compressors in mind and patch friendly to my room. These will not be patched into the patch bay all the time. If I want to patch them in, I just grab a cable and do so. Mostly because it does not sit in the rack with patchbays or other gear

Conversly, the 4 API preamps I first racked in a regular metal enclosure have XLR ins and outs. After I made that unit, I realized I should have used TRS on the output side. So the next APIs I racked have XLR in and TRS out. Again so I can use the same TRS patch cables for everything. There is no sound difference that I have found with XLR vs TRS. Just compatiblity with your gear. My preamps at my studio do not run to a patch bay. I ran them to just a cable (snake) that ends at the front of the patch bay. I then can just plug any channel from the cable to the patchbay input. The reason I did this was to limit the number of connections in the path. There is something like a .5db of loss per connection. Everytime you add another connector or contact on a patch bay can loose signal and induce noise. So XLR or TRS outputs do not really matter to me except at the patch bay end on Preamps. Inputs are standard XLR.

JD

Grounding. I find that star topology is best. If you see on the back a small hole at the top left of the box? That is where I will run all grounds. A lug with star washer and nut will work great.

BTW, the back is actually stainless steel, as that was all I had. Anyway, basically run every thing individually to a lug should be quite.

Hope this helps, and keep the questions comming.

JD

Im still a little confused about some of the PSU issues. What kind of connector is that on the back for the power? Wouldn't you normally use a four pin XLR connection? Also Im having trouble finding any appropriate PSU's on e-bay or any sources that sell just a power supply new.

I'm also not sure how to evaluate what a PSU is capable of. For instance, I know from what you've said that for API, OSA, BAE, etc. I can use a PSU rated at +/- 18v. I need to know the right current to decide how many modules that will power though, right? Well how do I figure out how much current I would need for a rack with a variety of differnt modules. Also what kind of issues does phantom powering create if any?

API and most others need 65ma to run. You should really have 2 to 3 times that amount for when the module is really hitting hard. So maybe 125- 150ma per module. It depends on how many you rack. A half amp (500 ma) should be good for 3-4 modules.

I used a barrier strip on this one. I could really use any type of connector. This is what I had. Other times I go out and buy everything.

JD

http://www.jlmaudio.com/JLM%20Power%20Supply.htm
Joe has a couple of power supplys that I can vouch for. The 5 output one would work great for
various card design (API 500 etc). If you have an old computer power supply you can gut it use the can and the heats sinks. The toroid transformers I get from Digikey made by amveco. You can also get various pin numbers in xlr up to seven so an interconnect is easy. With transformer and full kit your less then a hundred bucks.

I have 16 mccurdys in 2 racks...the only problem is that they have a minus 10 db pad across the output...does not help with overloading the preamps on input signal, so things like drums overload the inputs...how can i change this

Pad the input. You can purchase 10db pads, or make your own.