On-Location Power Conditioning

[dbro]

(First Post)

Hey Everyone - I'm getting back into location recording after a 10 year absence and am going through my old rig to make several upgrades and replacements. I'm staying in the acoustic music market and work mainly with minimal micing – but that's beside the point.

I've got a mobile rack on casters that I take on-location and need to get a stable power source for my racked equipment. I've looked through what's available in the market as far as power conditioning and I'm not satisfied with what I see from the A/V manufacturers.

The products available from A/V suppliers (Equitech, Furman, and Monster) don't seem to be up to the same standard as what's available from IT suppliers (APC, et al). In fact, after looking through the websites, I'm left with a green-marker/home theater feeling from the A/V guys and a sense of reliability from the IT suppliers.

Based on what I've read and experienced I'm thinking of going with a rack-mount APC unit. Has anyone else gone the same route?

What do you do for on-location power conditioning?

[rumleymusic]

I'm left with a green-marker/home theater feeling from the A/V guys and a sense of reliability from the IT suppliers.

I have used conditioners for IT purposes and from what I have experienced, they do little to reduce AC noise from the equipment. They provide constant and steady power, but I trust the home theater/pro audio maker's conditioners more for noise reduction.

Actually, I had an APC unit that caused me more trouble than good. It decided to go haywire in a live broadcast and I lost all power to my equipment.

[klaukholm]

take a look at products for the medical industry. They have very stringent requirements and there are a number of good products available.

[Teddy Ray]

I use Richard Gray products.

Richard Gray's Power Company

Won't leave home without them.

[dbro]

Good information - Thanks guys.

Derek

[noamraz]

Hi Derek,

Any news on that matter?

[Don S]

Originally Posted by Teddy Ray

I use Richard Gray products.

Richard Gray's Power Company

Won't leave home without them.

Which of their products are you taking in the field?

[dbro]

Originally Posted by noamraz

Hi Derek,

Any news on that matter?

Yes. I've decided to go with an APC 1500 in a 2U rack-mount chassis. It's definitely an IT product, but it's got everything I was looking for.

Derek

[Teddy Ray]

Originally Posted by Don S

Which of their products are you taking in the field?

Richard Gray Model 400 Pro

[5flagsaudio]

I use a double conversion UPS; in my case, a Tripp-Lite unit. Then I follow that with a "power conditioner" just for the extra outlets. It's a 90 lb 4u rack that's a pain to load, but it's saved my recordings once already during a 30 second power outage during a concert.

[HughH]

Hello,
If I'm not mistaken the APC unit puts out a "modified sine wave" waveform that is sort of a three step square wave instead of a sine wave. This is fine for IT where everything is on a switching supply, but if you have any audio gear with linear power supplies this will dangerously overheat the transformer and potentially cause failure.

Hugh

[dbro]

Originally Posted by HughH

Hello,
If I'm not mistaken the APC unit puts out a "modified sine wave" waveform that is sort of a three step square wave instead of a sine wave. This is fine for IT where everything is on a switching supply, but if you have any audio gear with linear power supplies this will dangerously overheat the transformer and potentially cause failure.

Hugh

Good point. Most inexpensive units (and some in the cheaper APC lines) will output modified sine waves and can be dangerous to linear old-school power supplies.

My unit is part of the APC "Smart" series that outputs a sine wave in normal operation. When the battery kicks in for a total power failure the DC inverter outputs a modified sine wave that degrades to a stepped sine near the end of the battery charge.

I'm less interested in using the unit sans-power for any extended period so I'm not worried about getting into stepped sine territory.

Derek

[Gravity]

Originally Posted by 5flagsaudio

I use a double conversion UPS; in my case, a Tripp-Lite unit. Then I follow that with a "power conditioner" just for the extra outlets. It's a 90 lb 4u rack that's a pain to load, but it's saved my recordings once already during a 30 second power outage during a concert.

Which Tripp Lite are you using? I just picked up a SU1500 series (the just discontinued one, not the newest one)

Mine says not to use it with power conditioners after, but i can't imagine why.

How do you like yours? It's a heavy sunnovagun. I jsut wish it were quieter.. the fan is getting to me...
:-P

[Audiop]

Looking at UPS right now and I think I have the solution for me. A 300W or 600W DC/AC converter (or inverter as they are called) with a sine output. Price is about 130-200€.

I will feed the inverter with a standard SLA car battery and hook a charger up on the other side. Total cost will be somewhere in the neighbourhood of 300€. Possibly I'll add a filter between inverter and gear if deemed necessary.

For this I will build a small wooden case with a sturdy handle and wheels for easy placement away from the recording area if needed. Have no idea how hard the fan will work under typical load and temperature.


/Peter

[Remoteness]

Peter, it that inverter true Sine wave or stepped Sine wave?
It make a big difference.

For the folks that may want to know...
A convertor converts AC to DC; an inverter inverts DC to AC.

[noamraz]

Originally Posted by dbro

My unit is part of the APC "Smart" series that outputs a sine wave in normal operation. When the battery kicks in for a total power failure the DC inverter outputs a modified sine wave that degrades to a stepped sine near the end of the battery charge.Derek

Have you chose the On-line or Interactive version, Are there any advantages to the Interactive vs. the On-line version?

Cheers, Noam.

[Kyle S]

Peter-

I am building something very similar. I have other areas in need of severe upgrade so I can't spend 1200 on an inverter alone, I would like to, but its not really an option.

I've been digging through sites looking at inverters for about 2 weeks. I've found these Xantrex Prowatt SW2000 2000W True Sinewave Inverter on sale at JTH Electronics at the lowest price available - which seem suspiciously cheap. Gotta be a catch somewhere.

I haven't yet figured out the current I'm drawing so everything is dependent upon that, but I am sure its not anywhere near 2000w. I would love to find a ProSine being given away somewhere but wouldn't we all. I'm gonna get a charger to go along with the sealed battery and box it all up. One A/C cord is going to run to the filter/reg/strip in the audio rack and then everything else from that.

I'm going to make a front panel with some analog meters to watch all my power. I was thinking of making some cheap sacrificial box to place between the charger and house power incase of lightning or whatever.

I think this should cover the bases. I don't know how many batteries I'll be using yet but it wont be anymore than two. I need to pick a battery yet as well.

[MichaelPatrick]

Derek, I'm glad you found what you are looking for. You may want to read up on power, and there are some informative posts here.

You bought an uninterruptable power supply (UPS) that will keep gear running when the power fails, but it probably won't condition (quiet) the power for audio applications. As others have said, it may be even noisier.

I use an Equitech which works really well, but heavy enough to need a wheeled rack case. I also use a small CyberPower battery backup to keep the recorder running if power fails. It is passive when power is OK, which helps to keep the line noise down, and it also helps that the recorder it supports is only used as a digital device with no analog signal to pickup noise.

[Audiop]

Originally Posted by Remoteness

Peter, it that inverter true Sine wave or stepped Sine wave?
It make a big difference.

I have looked on true sine wave inverters Steve. One manufacturer had a 3% max. THD spec on the output. I think that's good/clean enough, otherwise I slap a filter on the output. I have a scope so I can check for HF dirt on the outputs and I will likely do some listening test to see how my DIY solution perform compared to power directly from the wall.


/Peter

[7rojo7]

I have an 8kVA Riello smart line interactive UPS followed by an 8kVA custom made isolation transformer with 1 CEE16 with a 10 amp breaker out and 5 PowerCon with 10 Amp breaker outs, which give me 15 minutes of autonomy at 5kW of ultra clean current, no sags, lots of bass.
I'm selling them, they are now in passive to active ventilated ATA case in case flights with desert proof cable passes. They weigh a ton together.
Europe 230 volt single phase 50 Hz
No Noise, bomb proof. Although I would probably put a really big Zener Diode before it if I was to do it again, but that would be really easy to do for someone who wanted to.
And lead line the cases against stinger attacks

[MichaelPatrick]

Originally Posted by 7rojo7

I have an 8kVA Riello smart line interactive UPS followed by an 8kVA custom made isolation transformer with 1 CEE16 with a 10 amp breaker out and 5 PowerCon with 10 Amp breaker outs, which give me 15 minutes of autonomy at 5kW of ultra clean current, no sags, lots of bass.
I'm selling them, they are now in passive to active ventilated ATA case in case flights with desert proof cable passes. They weigh a ton together.
Europe 230 volt single phase 50 Hz
No Noise, bomb proof. Although I would probably put a really big Zener Diode before it if I was to do it again, but that would be really easy to do for someone who wanted to.
And lead line the cases against stinger attacks

Now your talking. Remote audio ready for war!