1. Register NOW and become part of this fantastic knowledge base forum! This message will go away once you have registered.

Power conditioner for mobile unit

Discussion in 'Pro Audio Equipment' started by BobRogers, May 23, 2006.

  1. BobRogers

    BobRogers Well-Known Member

    I'm getting an Alesis HD24 for use as a mobile unit. I'll be doing some outdoor concerts where I'm not as confident of the power source as I would be indoors. I usually use the typical Furman rack rider power conditioner for my PA rig. What do you all use with mobile recording rigs?
  2. AudioGaff

    AudioGaff Well-Known Member

    The Furman cheap Rack Rider stuff is no power conditioner. It barely qualifies as a surge protector. You want the newer Furman expensive stuff that has much better protection and power filtering. You should also get thier voltage stablizer. I forget the model number, but is meant to output a constant 120V (+/-) a few volts, so that when the power under or overshoots you are protected from that as well. Portable power generators are known to swing voltage out of the normal range rather wildly at times.
  3. JoeH

    JoeH Well-Known Member

    I'm on the fence these days about lugging around a big old heavy UPS. (which is basically the equivalent of a couple of car batteries in a case with a lot of lead reinforcement.)

    With the price of gas nowadays, it actually DOES factor in to my cost of transporting gear. Of course, a good power FILTER is great, esp if its built into a strip of AC outlets.

    But consider this much: for 99% of the venues I'm in, if the power goes down, the WHOLE THING goes down, show and all. I worry more about gaffing my AC cable/connector to a safe, reliable, clean outlet more than anything else, and I make sure there's no lines running across doors or walkways - anything that could get cut or pinched or trip someone.

    This thought occured to me not all that long ago when I set up my gear in the FOH booth, alongside the main console. We were all on the same breaker, and I simply had a split from the stagebox snake. Aside from that, the FOH console was there (all digital) as was all of the processing. Ditto for when I'm backstage at an acoustic concert. If MY power goes, so does the lights and other important stuff. (And if the power goes, the emergency lights come on, alarms go off, etc.)

    Sure, one can pop an individual breaker at some point, but if you've got gear that's defective, it's going to pop the breaker in your UPS as well.

    I'm just not so sure it's worth lugging around anymore, at least not in my small "guerilla-style" rig. In a bus or a remote truck, SURE, but otherwise......

    I think perhaps just a small UPS or battery for the computer itself is a good idea, to give you a moment to shut down properly. But even so, I use Samplitude/Sequoia with a Sony Vaio Laptop w/battery, running to an external FW HD, and thankfully, every time (although rare) the power has gone down with a catastrophic total loss, I've still gotten my files back - including the ones that were abruptly halted. (Yeah, I'm lucky, I know. :wink: )
  4. RemyRAD

    RemyRAD Guest

    Bob, I use a industrial electrical "Signal Transformer" and wired my truck for balanced power. Once I put that thing in all of my problems vanished, like magic! Of course something of this nature may not be an option for you but Furman is now offering a rackmount balanced transformer power distribution unit that is rackmounted. Now this is not an UPS or uninterruptible power supply but a clean power conditioner that will also improve signal-to-noise while offering the highest electrical isolation. I believe they are available in 20 and 30 amp versions. Now if you couple that to an UPS at the output of that unit, you would have ultra clean, stable power with battery backup. But if you want the best, try a Liebert computer power system. That's what they use on the Sheffield trucks, at only $4000 a pop, click, fizzle, zap!

    Electrofortified with eight important vitamins and minerals that helps build strong mixes 12 ways.
    Ms. Remy Ann David
  5. MadMax

    MadMax Well-Known Member


    Are you going truck or trailer? (I found it makes a BIG difference!)

    In either case you DEFINITELY need to look into a UPS if you're using the HD-24.

    I performed some extensive testing, (and still have more to do to complete the permutations), but so far my testing confirms what the vast majority of HD-24 users have experienced; if you should loose power BEFORE hitting the stop button on the HD-24, your tracks are at the very least MANY hours and/or dollars away from be recovered... if they are salvageable at all!

    The reason why the truck vs trailer question will be your grounding scheme.

    Gotta run, I'll complete my thought later...

  6. FifthCircle

    FifthCircle Well-Known Member

    My location rig always includes a Furman AR-1215 (or 117) in it. Single rack space kept in its own case, regulates even the worst power to 117v+/-3. I also bring a small UPS for my computer. The issue you run into while recording with hard discs is if power goes out, you can often loose everything you've recorded (at least until you have hit stop and the files have been written). I can deal with the stop in the show. I can't deal with loosing what I've recorded to that point.

  7. MadMax

    MadMax Well-Known Member

    OK, back to it...

    Your grounding and UPS's have GOT to play well together...

    Some UPS's that are "computer grade" aren't clean enough for audio grade. They might hold voltages tighter, but they are far noisier on the ground plane and will kick all kinds of noise into the audio path.

    I'd have to recommend that you get a refurbed unit, but get one from someone reputable like APC. (Just an example name, not an endorsement!) Be sure that you can return/exchange it just in case you get one that's noisy.

    The refurb units are just as solid as the new units, they might just be a bit heavier and or batteries may not have as much/long holding power... but then again, there's something to be said for 25-50% of the cost, no?


    If you run a truck, just be wary of the potential for ground loops between the building and the truck. Especially if you are running on a genny'. I think there's probably a few other higher end remote operators like Remy and FifthCircle who can give you better pointers than I can on this truck/rig grounding stuff.

    I run a trailer... I sink a grounding rod and tie to it and tie the incoming power to it, through my panel via a #4 stranded cu. No loops.

    In either case, run a standard star ground system. From each main outlet, run a single ground back to the panel ground bus. From each chassis gnd, run a single ground run back to the panel ground bus.

    If you are just carrying racks in, then it gets a bit tricky for star grounding... What ever your main disconnect is, run all your power and chassis grounds to the main ground bus.

  8. uburoibob

    uburoibob Guest

    Just out of curiosity, are you going new or used? I am about to be putting an HD24 up on the market. It's got about 120 hours on it, as well as an extra 80 gig drive. I am wondering what they are going for. I also have an MultiMix 12R Alesis rack-mount mixer that I have used for recording 8 tracks in a live setting. Both housed in a rack bag, with insert cables.

    If this is the wrong thread, I apologize. Not trying to sell it here, just get a feel for its worth. I am thinking around $1200 would be right.

    Thanks in advance.

  9. MadMax

    MadMax Well-Known Member


    I don't have a bluebook to look one up, but try either this or watching for low milage units on eBay.

  10. BobRogers

    BobRogers Well-Known Member

    Thanks for all the replys. I got a Furman 1215. Probably should have done it a long time ago. Still kind of overwhelmed by all the choices of UPS.

    I am going to be hauling my racks into the show and running the Alesis along with the board.

    I went with a new rig. The ones on eBay in the condition that I would buy seemed to have held their value pretty well. It's my first time with a mobile rig, so I felt the warranty, ease of return, and tech support was worth the price difference.

Share This Page