Hi all,
I need to record from a PA system with an XLR3M output connector to an Olympus DS-2 digital voice recorder (DVR) with a 3.5mm mini-plug mic input. The PA system is a modern rack-mount with several components and an LCD touch-screen controler.
For my first attempt, I tried using the 1/4" headphone monitor output present on one component of the PA system, but the test recording had horrible static, even when the PA was silent. I tried the same recording setup using the headphone jack on my iPad (except the 1/4" to 1/8" adapter plug) and the result was perfect, leading me to believe that PA output was the problem and I need to try a different output.
The other output of the PA system is on a different component, in the form of an XLR3M output connector. I bought two adapters from my local music shop: the Hosa MIT-156 Impedance transformer XLR3F to 3.5mm TRS, and the Hosa GXJ-183 1/4" TRS to XLR3F adapter. I have a separate 1/4"M to 3.5mmF stereo plug for the latter. Will either of these work? The mic input to the DVR is a stereo mini-plug, so I assume the plug connections, base to tip, are ground, right and left, while the mini-plug on the MIT-156 adapter is ground, hot and hot. That adapter drives the leads of primary of the impedance transformer with the hot and cold pins, and the secondary gets the output and the common lead. Seems like this should provide mono sound. My success with the iPad leads me to believe the DVR is able to adapt to receiving line level output to its mic input. The specs on the DVR's mic jack are 2kΩ and -70dBv.
I need to record from a PA system with an XLR3M output connector to an Olympus DS-2 digital voice recorder (DVR) with a 3.5mm mini-plug mic input. The PA system is a modern rack-mount with several components and an LCD touch-screen controler.
For my first attempt, I tried using the 1/4" headphone monitor output present on one component of the PA system, but the test recording had horrible static, even when the PA was silent. I tried the same recording setup using the headphone jack on my iPad (except the 1/4" to 1/8" adapter plug) and the result was perfect, leading me to believe that PA output was the problem and I need to try a different output.
The other output of the PA system is on a different component, in the form of an XLR3M output connector. I bought two adapters from my local music shop: the Hosa MIT-156 Impedance transformer XLR3F to 3.5mm TRS, and the Hosa GXJ-183 1/4" TRS to XLR3F adapter. I have a separate 1/4"M to 3.5mmF stereo plug for the latter. Will either of these work? The mic input to the DVR is a stereo mini-plug, so I assume the plug connections, base to tip, are ground, right and left, while the mini-plug on the MIT-156 adapter is ground, hot and hot. That adapter drives the leads of primary of the impedance transformer with the hot and cold pins, and the secondary gets the output and the common lead. Seems like this should provide mono sound. My success with the iPad leads me to believe the DVR is able to adapt to receiving line level output to its mic input. The specs on the DVR's mic jack are 2kΩ and -70dBv.
I think connecting a +4 dBu nominal professional line level signal to a microphone input and/or to a microphone transformer is asking for trouble. Why not attenuate the microphone signal by 40 dB or so using a simple resistive voltage divider?
If I were you I'd buy two female XLR plugs, a 3.5 mm stereo plug, two 1 kohm resistors, two 10 kohm resistors, two 100 ohm resistors and some shielded cable and connect it like this:
In each XLR plug:
1 kohm from XLR pin 3 to XLR pin 1
10 kohm from XLR pin 2 to the centre conductor of a shielded cable
direct connection between pin 1 and the shield of the cable
100 ohm between the centre conductor and the shield of the cable
The shields of both cables to the sleeve of the 3.5 mm plug
The centre conductor of the left cable to the tip of the 3.5 mm plug
The centre conductor of the right cable to the ring of the 3.5 mm plug
If I were you I'd buy two female XLR plugs, a 3.5 mm stereo plug, two 1 kohm resistors, two 10 kohm resistors, two 100 ohm resistors and some shielded cable and connect it like this:
In each XLR plug:
1 kohm from XLR pin 3 to XLR pin 1
10 kohm from XLR pin 2 to the centre conductor of a shielded cable
direct connection between pin 1 and the shield of the cable
100 ohm between the centre conductor and the shield of the cable
The shields of both cables to the sleeve of the 3.5 mm plug
The centre conductor of the left cable to the tip of the 3.5 mm plug
The centre conductor of the right cable to the ring of the 3.5 mm plug
I just did this over the weekend with a zoom recorder. Do not try to use the mic input use a line input and tap a line output on the PA desk.. don't use the main outputs the signal level is too hot.
In my case I used the record outputs on the PA console which were RCA and that was fed into the XLR/TRS inputs on the recorder. With signal levels in the green on the desk the recorded sound was crystal clear on the recording apparently.
In my case I used the record outputs on the PA console which were RCA and that was fed into the XLR/TRS inputs on the recorder. With signal levels in the green on the desk the recorded sound was crystal clear on the recording apparently.
First you have to make sure that output jack is actually providing a useful signal.
I'm involved in installing many "modern rack-mount" PA systems. Not one of them provides a record feed unless the client desires us to program one into it.
On most of our racks the only 1/4" headphone type jack you would ever find would be the one on the CD player or some wireless mic receivers.
So you need to talk to the manager of that system and have them open it up and find you a line-level output -it may have to be programmed into the system DSP and a jack actually wired-up.
If the system you are dealing with is much simpler than what I described then it's really helpful to post pictures or at least names and types of the individual devices in the rack
You may need an isolator with transformers. The Radial SB-5 StageBug is one such device with a fairly low cost, may work for you. It is intended to isolate the output of a laptop's audio output to feed an analog mixer. Since this is a passive device, such a device used backwards to take your balanced outputs from the mixer and convert it to a stereo unbalanced signal on a 1/8" stereo plug. Do not use the XLR output of the SB-5 as an input. Instead use the 1/4" outputs as inputs. You will need to get or make a pair of XLR to 1/4" TRS plugs. There the + pin of the XLR goes to the tip and the - pin of the XKR goes to the ring. Try it with the pad on or off. The pad on the SB-5 inserts a 100K resistor in series with each channel of the 1/8" plug.
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