Audigy Platinum Sound card with phantom powered microphone?

Hi, All,
I have an older Soundblaster Audigy Platinum sound card. I also have two microphones. One is a cheap little one like a lapel mike with a 3.5mm plug on the thin little cord. The second is an Audio-Technica AT3035 which requires phantom power (which I have). I’ve successfully recorded with both.

On the Audigy Drive there is a jumper. This is supposted to be open (no shunt on it) when using the cheap microphone and closed (shunt in place) when using the AT3035.

The problem is it’s a pain to switch from one to the other.
The question is: What are the consequences of using each mic when the jumper is set wrong? Will is destroy the mic? Mess up the sound card? Ruin the sound quality? What will happen? I don’t really want to try experiments until I can be sure I’m not going to fry something expensive.


I wouldn’t be surprised if they made you turn off the sound card’s phantom power. See bottom illustration here…

I would not want the AT phantom 48VDC getting mixed up with the sound card’s 5VDC. That’s the compulsive engineer talking, however, I don’t actually expect any damage to occur. The microphone will have significant circuitry to keep the two batteries apart. Probably.

You’re using a large diaphragm condenser microphone to feed signals into the Mic-In of your sound card? This is only until you can get a proper preamplifier and USB adapter, right?


You’re using a large diaphragm condenser microphone to feed signals into the Mic-In of your sound card? This is only until you can get a proper preamplifier and USB adapter, right?

Koz is obviously suggesting that I’m not doing things the best way. Is it that what I’m doing is like using a sledgehammer to drive a picture hook into the wall, or what? I’m a sound recording novice of the first order, and really don’t know what I’m doing. My goal is to make reasonably good recordings of some of my didjeridu playing, but without totally breaking the bank (my new hearing aids already did that.) Please enlighten me a bit.


Can we go back to your original post - there are several versions of the Soundblaster Audigy Platinum sound card - exactly which one do you have?
The Audio Technica AT3035 Mic requires a nominal 48v phantom power (11v to 52v) which you say you have - where does the phantom power come from?
The “jumper” you refer to - is there an on-line manual that shows this? What exactly does the jumper do?
The Audigy Platinum cards that I have seen have 1/4" sockets, whereas the AT3035 Mic usually uses a 3 pin XLR plug, so how are you connecting the two together?

I don’t mean to suggest it wouldn’t work. It probably will. But nobody I know has ever accused a PC sound card of high quality audio – and it’s not a distortion problem. The electrical atmosphere inside a PC is poison to a high gain sound card. Ever try to run a radio, either FM or AM next to a computer? It’s not fun. Some microphones need to be amplified a thousand times – I’m not joking – to produce a show.

My SoundBlaster Live 5.1 card came with very firm, clear instructions to plug it in as far away from other electronics as I could. If I could plug it in across the street, that would be fine with them. So after we get your problems solved and you get used to using the Mic for personal performances, you will run into the noise floor – usually when you try to do special effects, or amplify a delicate violin solo performed an unfortunate distance from the mic.

The semi-good news about being a newbie is you will probably run into physical noise long before anything else. “OK, the Metro Bus goes by every fifteen minutes. If we unplug the refrigerator and start right away…”


at least not your average consumer grade sound cards - but the Audigy Platinum cards are way ahead of the average PC sound card (as reflected in the original price tag) and some versions have all of the high gain analogue parts in an external unit, but as mentioned before, the same name was used for some very different hardware. The best provided 24bit (32 bit internally) 44.1/48/96kHz, and extremely low latency when used with ASIO drivers (ASIO not supported as standard in Audacity), hardware mixing and a useful DSP chip for digital effects with no additional CPU load. Also with good MIDI support and excellent sound synthesis capabilities thanks to comprehensive SoundFont support (again in hardware).

A slightly odd thing about many of the SoundBlaster cards, including the Audigy’s is that the sound quality from the rear outputs is markedly better than from the front outputs. This is taken into account by the excellent, though rather complicated third party kX drivers which swap front and rear outputs by default.

but one thing I’ve never seen on an Audigy Platinum is 48v phantom power.

Here’s the setup: The sound card is the first edition Audigy Platinum card with no extra initials or numbers. It was a very nice card for the time (Fall, 2002), with all the features Steve described. The manual is here (2.5 Meg, English, French, Portugese, and Spanish)

The jumper that I mentioned is described on page 1-3. There is no information that I can find anywhere about what the jumper does. Since the cheap mics get 5V DC power from the jack, I suspect that puting the shunt on the jumper eliminates that 5V since the better mic with its own power supply does not need it. That’s a guess only. When I have the jumper set for the good mic and record from the cheapie, it only gets a hum. I guess the jumper really is needed.

A 12V DC wallwart powers the phantom power supply. The AT3035 does indeed come with the 3 pin XLRm plug. The mic is connected to the power supply with a 3pin XLRf to 3pin XLRm cable. The connection to the sound card has a 3pin XLRf connector at the power supply end and a 1/4 inch, 2 conductor phone plug on the other which plugs into the 1/4 mic jack on the Audigy “drive”. This resides in one of the front drive bays on the tower PC. On the Audigy drive the 1/4 inch mic jack has a control knob. All the way left (past a slight click) means the jack is treated as line-in. The knob anywhere to the right makes it into a mic-in jack with a variable recording level.

When the mic is connected as described above, with the jumper set correctly, it does record nicely, except, as several of you pointed out, it picks up a lot of environmental noise – PC fan, chair squeaking, etc. Getting a good recording environment is going to be a challenge, since I don’t want the PC itself to be close. Luckily, the cables from mic to PS and PS to PC are about 25 ft (4m) long. For the didjeridu, I think I’m going to have to build a sound isolation box to surround the bell of the didj and the mic.

Thanks everyone.

USB microphones appear to be a really good deal until you find out how closely tethered you are to the computer.

The 3-pin XLR connection on the bottom of the microphone–assuming it’s normal – is designed to go hundreds of feet. That’s one significant difference right there. When they shoot Meet The Press, it’s usually set up in NBC Washington Studio A. Washington Control A, the room with the sound board in it is over 125 feet away. In New York Rockefeller Center, it’s not unusual for the studio and control room to be on different floors.


It’s not very clear, and Creative could so easily have said “the jumper provides 5v for computer microphones” if indeed that is what it does.
The fact that it mentions 3.5mm jacks for “condenser” microphones suggests that this is indeed what it does. An easy way to tell is to get hold of a normal cheap computer microphone and try it. If there is no 5v, then it will not work (it will do no harm, it will simply not work) With 5v, the computer microphone will work normally. If I understand correctly, this is the test that you have done and you have confirmed this is correct.

For your set-up the shunt should be present.

You will not need to remove the shunt unless you wish to connect a cheap computer microphone.