Hi Bill- This is probably not the answer you hoped for. AC power is
used with a number of these mic pres apparently because the circuitry
is simpler for realizing the necessary 48 volts for phantom power. We
did get an Audio Buddy to run some phantom power mics using 4X 9volt
DC batteries for mics with lower phantom power requirements like the
NT-1A's and MKH's (2-3ma if I recall). The CAD 179's have high
current pull as condenser mics go, ~8ma. You might be able to make a
larger, more powerful battery pack but its going to be expensive
battery-cost-wise and bulky because you need at least 36 volts (2X
18-22 volts). Email me directly if you want the DC modification
wiring diagram we used. Our next approach was to see if we could
modify a DC to AC inverter to kick out the low voltage AC increasing
efficiency and lessening the chance of interference. That project is
still on the bench. You can make a pretty hefty 12 volt DC battery
pack and try one of the cheap, half-wave $30, DC-AC inverters.
Sometimes there's no interference-- other times, its impossible to
get rid of. The Audio Buddy is pretty susceptible to interference.
Cheap, low noise DC powered mic pres with adequate phantom power are
hard to find. I run a Symetrix SX202 that I bought on eBay for $150
on a dc-ac inverter and it usually works without interference if I
place the pre a cables a ways from the inverter. It may be one of
the quietest mic pres for the bucks. Full wave inverters have less
interference, but they're still not perfect and they're about 4-5X
more in cost. Sorry if our modest success using 4X9 volts with the
Audio Buddy and NT1A's misled you. Best, Rob D.
At 5:41 PM +1000 8/25/04, Bill Rankin wrote:
>Hi All
>
>Way back in February this year there was a discussion on the CAD
>M179 microphone which Walter,Klas and others reckoned was a pretty
>good low noise mic for the price. So recently, when my wife had to
>go on a business trip to the States I took the opportunity to
>suggest that she by me a present while she was there ;-)
>
>Now, realising I also needed phantom power for the mic I thought I
>would also get the small "Audio Buddy" a dual preamp and phantom
>power supply unit which had also has been previously mentioned by
>members of this group as a good unit.
>
>However I think I outsmarted myself. I thought the Audio Buddy would
>be able to be powered in the field using a gel cell battery by
>dropping a 12v down to the required 9 volts but on unpacking the
>unit back here in Australia I find that the 9 volt power required is
>9 volts AC not DC as I originally thought. I guess I didn't read the
>specs properly.
>
>Do any of you electronic experts know how I can power the Audio
>Buddy in the field? I am only a novice in the soldering iron
>department but can follow a basic diagram.
>
>I intended to use this setup in the field with an additional CAD
>M179 mic (if the first one turned out to be satisfactory) for stereo
>atmospheres and so weight was not going to be a problem once I had
>carted the stuff to the right spot of course.
>
>
>
>Bill Rankin
>Australian Wildlife Sound Recording Group
>
>
________________________________________________________________________
________________________________________________________________________
"Microphones are not ears,
Loudspeakers are not birds,
A listening room is not nature."
Klas Strandberg
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