Wiring/Cabling Questions

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Executivos

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I'm going to buy a headphone amp and run my monitoring correctly now. I have some questions about running cable lengths.

My control room is seperate from my live room, and all equipment is in the control room.

I'm looking at the behringer headphone amp and it has four seperate channels to send. Right now for headphones in the other room, I just made my own cable to run from the output of my headphone jack on the digi 001 into a female jack in the live room and I plug 1 set of headphones in there.

I'd like the keep the headphone amp in the control room and run 3 signals out to the live room.

The way I made the cable was basically cheap THIN speaker wire. (it's like 24 awg) There's actually 4 wires for one stereo channel in the setup I have now (I split the trs jack into two seperate signals and then it comes back into one. As you can tell I don't know that much about this stuff) The problem is that they buzz a bit. Is this because it's unbalanced or because I'm not using the correct cabling. The run is about 25-30 feet.

My question? I need to run 3 stereo signals carrying the powered load 25 feet. How can I do this and minimize interference? What cable/awg should I use?


Also does anyone know the ABSOLUTE cheapest mic preamp available? It's just for my talk back mic...all I need is some gain. I took an xlr cable and put a push button switch in the loop so that it would only loop when I push the button. Will a impedance transformer work for this? Or a $10-20 mic preamp if anyone knows of one (im dreaming I'm sure)
 
You're getting interference on a headphone line? That's odd, but not unheard of: if the headphone driver is indifferently designed, EMI that gets induced on the headphone line might well make it through the feedback loop and get amplified. Yucko: if that's the case, it might alsomake it back to the summing bus. . At least you do have the Behringer headphone driver to try, which ought to solve that problem.

24AWG is maybe just a little lightweight for long headphone runs, especially if your musicians are nearly deaf and you like to use low-impedance headphones like the AKG 240s. As you know, stereo headphones need 3 wires: right channel hot (tip), left channel hot (ring), and common return (sleeve). For a long time now, I've just made headphone extensions out of cheapo 18/3 portable cordage (good old beaterbox black power cable) from the local hardware store. It's cheap by the foot, easily available, and handles being flexed very well. Bulletproof overkill...

For the interference thing, I'd hook up the Behringer and drive your existing line with that. I suspect that it is more of an issue with the Digi's headphone driver than your wire: using the Behringer to buffer that output should fix it.

Cheapest mic pre? You could build one good enough for a talkback mic for $10, but that's only if you're up for the fight. The second cheapest would be to see what bundles there are at your local guitar store: for a long time, Guitar Center was *giving away* free Midiman Audio Buddies with the purchase of one thing or another. Failing that, probably the easiest would be to snag a Behringer 602 mixer: you'll get two pres with phantom power, a sometimes-useful summing bus, and a lot more flexibility for the longer haul. Behringer supposedly just lowered their prices by 50%, so you ought to be able to find those for $50-60. A transformer alone won't do it, though...
 
The headphone driver in the digi 001? when I put my headphones in here (in the control room) I don't get a buzz...When I use my "extension" into the other room, sometimes I get a buzz.

can you describe that wire you're using a little more? How much of a challenge is making a mic pre? I took electronics, ie: I know how to solder and stuff like that. Do you think they sell kits like they did in junior high? lol.
 
The headphone jack on the Digi is driven by internal driver circuitry- stuff that might well have been added as something of an afterthought, since that's not the primary purpose in life for that unit. If you get noise when using your extension to the other room, I susect that it is the Digi's driver circuitry that might be unhappy. That's why I suggest hooking up the Behringer headphone driver, and using _it_ to drive the extension. Since it is specifically designed for that purpose, it should have no problems at all.

18/3 portable cordage is strandard stuff at any hardware store: ask for it by that name, and they'll take you right to it. 18AWG, 3 conductors, black, white, and green (in the US, anyway- in the EU, it'd be blue, brown, and green with a yellow stripe...). You need 3 conductors, and that's just what it'd have. It also has a nice, flexible rubber jacket, and it is designed to absorb abuse: perfect stuff for studio headphone extension lines. It even fits into male and female 1/4"TRS jacks and plugs just like it was designed to go there.

A really _good_ mic pre is a cast-iron bitch to do well. But for a talkback-quality, *super*-cheap mic pre you can build yourself? Look here: http://www.hut.fi/Misc/Electronics/circuits/micamp.html

Use it with a 75-cent electret condenser capsule from Rat Shack, and save your good mics for recording... That Tomi Engdahl site is a great source for the do-it-yourselfer, or someone who just wants to learn a little bit of circuit design...
 
thanks SO MUCH! I'm going to check out that mic pre page. The talkbalk mic I'm using is the nady sp1....$10 from musiciansfriend. Not .75, but oh well. It still does qualify as a certified piece of junk :)
 
I was at lowes and I checked out the wire section, the only thing they had was 18/3 thermostat wire or something like that. The actual wire inside the jacket was solid, not in strands. I've never seen anything like that for audio. I assume this isn't the right stuff?

Also how hard do you think it would be to build that preamp? It looks easy enough, but I'm not sure. If I took those schematics to an electronics store do you think they would help me with it as in parts and a little explanation, or would they think im a waste of their time?

Or is it possible to find someone that would build it from the schematics for me without charging too much, seeing as how it's pretty simple? (I mean like if electronic stores sometimes offer a service like that)

Part of the reason I ask is that I know a few people that would like these and so if I can get one made, I can copy it and make some for my friends.
 
No, 18/3 portable cordage will be stranded, and will be in a round black rubber jacket. What you found was Romex- solid house wiring. Not useful for our purposes.

Many hardware stores have the Romex and the portable cordage in different areas, since they serve different purposes. I'd ask after stranded portable cordage, or power cord, or extension cord wire, next time through. They ought to have it- the only Lowe's anywhere near me does, anyway. So does Home Depot. Any little neighborhood Ace Hardware will, also.

That's just about the simplest imaginable preamp circuit. Building it would be a piece of cake, *if* you're comfortable with building projects like this. If not, juts save yourself the aggravation and buy and Audio Buddy or a Behringer 602. By the time you add up the cost of your time explaining to somebody else what you want, and trying to get them to build it for you, buying an off-the-shelf unit will be cheaper. The build-your-own route is only really viable if you are already comfortable with doing it, or want to take on the project just to learn those skills...

The only caveat is that that preamp is only going to be any good for talkback: the distortion is going to be far too high for any serious recording. Unless you have a bunch of friends with talkback needs, anyway!
 
What I would do is run balanced lines from the line outs on the digi 001(are they balanced) into the room and put something like the behringer 4channel headphone amp in there, then the musicans have some control over how loud their mix is.

Thats what I'm planing on doing but headphone amps and good headphones are near the bottem of my toget list which is around $30,000 long.
 
Me, too- but he said he wanted the amp in the control room, so there you are.

The way I do it is as follows: I distribute a rough stereo monitor mix (on balanced lines) to wall jacks at various places around the main studio. I also distribute the direct out from each instrument and vocal channel to the wallplate nearest where the performer is set up. I then feed the stereo pair, and the direct out for their vox and instrument, to a little Behringer 602 mixer at each location (that's right- I have _5_ of them). That way, each performer can control not only their headphone volume, but how much of their vox and instrument are in their own mix. They can twist their own knobs, so they can leave me alone...

The Behringer isn't much good for anything else, but for _this_ application it truly shines- and it's cheap enough to make doing this sort of thing worth it.

I have some pictures of my rig in http://www.homerecording.com/bbs/showthread.php?threadid=25365

Hope that helps...
 
well yeah, I kinda would like to learn how to do it. A bunch of my friends have been asking me to build them talk back setups...the push button and all, so their needs aren't for a great preamp.

My brother knows more about electronics, so maybe he'll build one for me :)

BTW, yeah I would like to have the heaphone amp in the control room because most of my clients don't understand simple things like volume knobs. I just set it up for them.

That idea with the behringer 602 is a damn good one though. If i had the need for a more serious monitoring situation, I would DEFINITELY go that route. Honestly I really only need one headphone signal in the live room, (I don't track drums here) the reason I want three is that sometimes, clients have wanted to track gang vocals and shouts all grouped around a mic, and a single headphone setup won't work too well.
 
Skippy Wow!

Nice setup their. I can't wait to find an old building and the money to build my studio.

Right now I do alot of location recording, usually at the bands jamming place. So what I'm going todo is get a small rack and some 16 channel snake cable. In the rack I'm going to put a panel of xlr 8 sends and 3 channels of DI's and a behringer 4 channel headphone amp(I think it has an aux input so that will be my last channel). The cable will be attached to that rack and will roll up into it. On the other end it will plug into my control room rack where I'll have a patch pannel or two, effects and preamps and such.

I just got another idea, I've been looking for some cheep heavy based mic stands for my expensive mics. I've been thinking of building my own with a mic case in the base. A little change in plan, I'm now going to build a rack and a mic case into the base of the mic stand. I could also put space for mic stands on board.
Basicly everything needed for the live room on one cart.

One question how did you mount the mixers ontop of the mic stands? It looks really neat.
 
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Atlas makes a female-thread mic gooseneck flange for mounting mics on podiums and whatnot- they cost about a buck. I just got some of those, and bolted them onto the back of some flat aluminum stock I had laying around the shop. Viola': instant mixer table that screws onto the male threads on top of a mic stand. I made a couple of double-size ones later (after those pix were shot), so that a Pod or the J-Station can cohabit with the mixer...
 
man................................................


WOW.............................................

I'm so impressed. I'm now going to try to win the lottery so that I can hire you at any price to build my dream studio :)


AWESOME WORK.
 
Thanks for the kind words! I guess I just learned a few lessons trying to operate a commercial studio (unsuccessfully!) in the late 70s and early 80s. When I built this room for my own private use a couple of years ago, I decided not to make the same mistakes, and tried to put in enough of everything up front. I hate rope salad...

Of course, in retrospect, I was hopelessly optimistic and behind the times to boot. If I had it to do again, I'd run 16 pairs, 2 runs of MIDI, 2 runs of CAT5, and 2 runs of RG58 from the mix position to each playing position. Audio, MIDI, SPDIF, firewire/USB/ethernet to each place. Oh, well: next time, for sure...

Try to envision how you'd use a room, *if you had an unlimited budget and lived in a perfect world*. Then, regardless of what your budget actually _is_, put in the right wiring to make your dreams possible as you build up the room. Reason? Wire is *cheap* when the walls are open, and hell-for-expensive once you seal 'em up.

I'd rather have a room prewired for 32 tracks and all the whoopie stuff right up front (even if I could only actually *afford* a guitar, an SM57, and a Portastudio), than to end up with good gear but an unmaintainable rat's nest of wire. You can always upgrade the recording and mixing hardware and outboard gear- but you're stuck with whatever wiring you build in up front, unless you're willing to shut down for long periods of time to rip it out...
 
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