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Gear / Technical Help => Ask The Tapers => Topic started by: darktrain on December 23, 2008, 04:44:24 PM
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I have read through some of the forum for this but am a little unclear, What is the best most compact phantom power supply and how long will it run on the batteries? Say for running very low pro with the 4022's, just 48v phantom, no pre. so it would look like this 4022's> ? > PMD620, seing if i can get more compact than the mixpre for "less than open" situations, that thing can get rather uncomfortable if you get my drift.
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seems like the ps-2 is the gold standard. sorry not sure on run times. never used one.
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seems like the ps-2 is the gold standard.
What he said. How much power you mics use will play a part in how long it will run. I have run it a good six hours with the low battery low never coming on.
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Didn't someone (DSatz?) mention once that you can hot swap the battery in the PS-2 and, if done quickly enough (i.e. not enough time for the unit to drain itself), you could continue recording with no signal loss?
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(re hot swapping the battery) Someone did tell me that here, but I didn't know it beforehand, and haven't tested it yet. One moment, please ...
... OK, I would have to say that it doesn't appear to be true. I just plugged a pair of Schoeps PHS 48 phantom powering testers (which draw about 4.5 mA apiece) into a Denecke PS-2 and put a 9-volt battery into place. The green LEDs in both testers came on, indicating sufficient voltage and current. I then took the battery out while leaving the testers plugged in. Their LEDs went out immediately.
A Neumann tester which I tried instead, that draws only about 1 mA if I recall correctly, stayed lit only for about one second after the battery was removed.
The only supply that I know of that is actually advertised to do this trick is the Core Sound "2Phant." However, it uses two 9-Volt batteries at a time, and is hardly the smallest phantom power supply available.
--best regards
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seems like the ps-2 is the gold standard. sorry not sure on run times. never used one.
yep
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I have a ps-2 for sale if you want one... pm me Nice unit just have power from all pre's and recorders so no need any longer
A
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Neumann makes a nice, small 48-Volt phantom power supply in versions for either one or two microphones. It's powered by a single 9-Volt battery and is rated, as I recall, at 6 mA per microphone. Its outputs block DC from your audio inputs with coupling capacitors.
But one way they keep the two-microphone version so small is that both its input and output sockets are XLR-5s. So if you're using two separate microphones rather than a single stereo microphone, you'd need adapters on both sides; some folks might not like that. Also, being from Neumann it's not inexpensive.
Schoeps hasn't made power supplies for microphones in many years, unfortunately. They used to make a nice series of supplies that were small, very solid, ran on two 9-Volt batteries, and had a small analog meter to let you see the battery voltage for yourself.
--best regards
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seems like the ps-2 is the gold standard. sorry not sure on run times. never used one.
18 minutes according to Core Sound. Can that be correct? It sure seems awfully short.
http://www.core-sound.com/2Phant/3.php
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seems like the ps-2 is the gold standard. sorry not sure on run times. never used one.
18 minutes according to Core Sound. Can that be correct? It sure seems awfully short.
http://www.core-sound.com/2Phant/3.php
Thats one of the articles i read also, but seems like 4+ hours is the norm for the PS-2 from what i have seen here
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18 minutes according to Core Sound. Can that be correct? It sure seems awfully short.
http://www.core-sound.com/2Phant/3.php
That's with running some awfully power-hungry mics through it (10mah). Most mics tapers use do not fall into that category. Some Earthworks come to mind, though. Check the draw of your mics to be sure.
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If the "low battery" indicator on a supply lit up (or perhaps, just barely began to light up?) 19 minutes into Len's test, that doesn't necessarily mean that the supply was no longer operating properly. The indicator could have been designed to mean, in effect, "You'd better get ready to change the battery some time in the next half hour, depending on what type of battery you're using." Or it could have been a unit that was out of spec. Precise, individual calibration adds substantially to the cost of production. In some markets it's more profitable to keep tolerances wide, wait for complaints, and make any adjustments on a case-by-case basis.
In order to make a really fair comparison he should have measured the phantom powering itself, and noted how long it took for that to drop out of spec. That's the only way to put the test on an equal footing for all the participants.
--best regards
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Have any of you guys considered running the mics with a lower voltage.
You can get away with this in some cases: Sometimes the mics have a builtin voltage step-up (50v polarization voltage), so they don't need the full 48v to polarize the capsule. Beyerdynamic MC930 fall into this class. Other times the element is electret and the phantom adaptor merely steps down to 9v or so anyway.
I built an adapter that has two 9v batteries in series and uses 2k load resistors. A set of blocking caps protects the the outputs. The box has (hardwired) a pair of female xlr pigtails for input and a miniplug pigtail as output. For my Beyers this gives 12v drop across the mics, which is within spec and it sounds great. I tried it on my AKG 463 and it did not work. I didn't try to diagnose the problem, but perhaps those mics take more current than the Beyers. This probably has to be addressed on a case-by-case basis, but if you're married to one set of mics, this may be worth investigating. Smaller package, and longer battery life are indeed possible in many cases...
Oh yeah, if you're using the DPA402x series, you *may* be able to power the capsule directly with a battery box. Has anyone done this? This is worth asking the DPA techs. I called to ask a question about DPA406x and got Bruce Myers on the phone! I bet someone like that would know...
Richard
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I have read through some of the forum for this but am a little unclear, What is the best most compact phantom power supply and how long will it run on the batteries? Say for running very low pro with the 4022's, just 48v phantom, no pre. so it would look like this 4022's> ? > PMD620, seing if i can get more compact than the mixpre for "less than open" situations, that thing can get rather uncomfortable if you get my drift.
imo, once you add the transformers to the ps-2 (which, ime, are required if you want to get the most out of the ps2), you are ending up with a form factor that is close to the size of the mixpre. that said, for the maybe 2 inches you would save, i would rather use the mixpre (plus you already own it). it is still going to be a second item besides the recorder going in and both are metal boxes.
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Some good points out there, may have to look into that Aerco after all.
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illconditioned, please forgive my bluntness but some of your statements are simply not factual, at least not in general. Microphones with internal DC converters (which step up the supply voltage so that it can the be used to polarize the capsule, often at something like 60 VDC) still have a definite range of input voltages that will they work with. Just because a DC converter is part of a microphone circuit is no reason to assume that the microphone will work properly with any other supply voltage than its manufacturer says.
That is even the case with many electret condensers, which nowadays includes some first-quality studio microphones (e.g. DPA). The people who design the electronics for professional quality microphones, particularly in Europe where standards are taken far more seriously than they are here in the U.S., don't figure on amateurs screwing around and guessing at what might work. Phantom powering is an international standard, and when those people design microphones, they assume that the powering will be delivered to the microphone as the standards specify.
In general, by underpowering a microphone you diminish its dynamic range, in some cases quite severely. It becomes less able to handle high sound pressure levels, and may also lose sensitivity and/or have a higher noise floor. What's more, even a relatively small deviation from the tolerances allowed in the standard can have a disproportionately large effect on a microphone's performance--but you might not find that out until the microphone is being used for live recording.
--best regards