xlr cable to mindisc

[leccy]

I want to use a microphone that has an xlr connection with my minidisc. Is it possible to solder a 3.5mm cord and connector to an xlr connection? I have some spare parts if this is possible.

What problems might there be, if it can be done?

thanks

[King Ghidora]

If your mic has a balanced output then you can't just rig up a connection to make it work. You'll need something to convert the signal to an unbalanced signal. Not all XLR cables on mics mean it is a balanced output mic. Some mics use XLR cables for stereo sound. If your mic is a stereo mic then it can't be balanced if the XLR cable only has 3 pins. It would take 5 pins for a balanced signal stereo mic.

If your mic is balanced probably the best way to convert to an unbalanced signal is to use a mixer that accepts balanced and unbalanced signals and has an unbalanced output. Sign makes a mixer that will do that. It's the Sign Video XLR-PRO which accepts both balanced and unbalanced mics and has an unbalanced output. The cheaper XLR Jr (on the same web page) will also work but it only accepts one input.

If your mic is unbalanced then you can use an adapter to connect it to your MD. There are adapters available especially for stereo mics that use XLR cables. I got two adapters of this kind with my Nady CM-2S mic which is a stereo mic that uses XLR cables.

Edited December 10, 2006 by King Ghidora

[Nathan P]

If your mic has a balanced output then you can't just rig up a connection to make it work. You'll need something to convert the signal to an unbalanced signal. Not all XLR cables on mics mean it is a balanced output mic. Some mics use XLR cables for stereo sound. If your mic is a stereo mic then it can't be balanced if the XLR cable only has 3 pins. It would take 5 pins for a balanced signal stereo mic.

If your mic is balanced probably the best way to convert to an unbalanced signal is to use a mixer that accepts balanced and unbalanced signals and has an unbalanced output. Sign makes a mixer that will do that. It's the Sign Video XLR-PRO which accepts both balanced and unbalanced mics and has an unbalanced output. The cheaper XLR Jr (on the same web page) will also work but it only accepts one input.

If your mic is unbalanced then you can use an adapter to connect it to your MD. There are adapters available especially for stereo mics that use XLR cables. I got two adapters of this kind with my Nady CM-2S mic which is a stereo mic that uses XLR cables.

Don't they make balanced to unbalanced cables? I've seen them at Sound Professionals and B&H Photo. I think they work but it's not quite optimal?

[King Ghidora]

I know that Shure makes a cable that will convert a balanced signal to an unbalanced signal. The reason I said a mixer is probably better is that you get more functions with a mixer and they really don't cost that much more than that cable Shure makes. There may be other cables that convert a balanced signal to an unbalanced one but I'm not aware of them.

[AllanH]

At the risk of being controversial - I'll say that it is possible to connect a balanced XLR output to a 3.5mm min jack.

For a mono XLR plug/socket (3 pins) the pin-outs are: Pin 1 = ground. Pin 2 = Hot (+). Pin 3 = Cold (-).

For stereo 5 pin plug/socket: Pin 1 = ground. Pin 2= Left Hot(+). Pin 3 = Left Cold (-). Pin 4 = Right Hot (+) Pin 5 =Right Cold (-).

To go from a stereo 3.5mm mini-jack to XLR 5:

1 Buy stereo mini jack to twin phono lead. Cut off the phono plugs (but remember which lead is left and which is right. The core insulation is usually red (right), white/clear (left)

2 Connect both phono lead screens to XLR pin1.

Connect left phono lead core to XLR pin 2

Connect right phono lead core to XLR pin 4

Connect 10kohm 0.6W metal film resistors between: XLR pin 3 and XLR pin 1, and between XLR pin 5 and XLR pin1.

A bit fiddly, but it works for me, connecting the output from 2 Rode NT1As (via a phantom 48V supply) into my HiHD.

AllanH

[Nathan P]

I think something like this would work. http://www.bhphotovideo.com/bnh/controller...oughType=search

[ozpeter]

It really depends on whether running the mic unbalanced (using a cable as suggested above) will matter. If the lead is quite short, you should be able to get away with it, without picking up too much hum and buzz. But if the mic is on a long lead, you would indeed first need to run it into a balanced input on a mixer, then from the mixer at line level unbalanced on a short lead to the MD recorder.

[King Ghidora]

That's the way I have understood the problem ozpeter. But I've never tried to make a cable directly connecting the balanced pins to an unbalanced cable as was suggested. The stuff I've read about it says you will get hum if you try it but since I haven't done it myself I can't really say for sure. I think the idea is that you get interference from the side of the balanced signal that you don't use. The longer your cable the more likely you'll hear interference because after all you have essentially two unbalanced signals side by side using the same ground in a balanced cable setup. Yes you can use one channel or the other but you will have about the worst possible situation going for a cable. You will have another cable running right with your signal carrying cable from one end to the other. You just stand a very good chance of picking up interference.

But like I say I haven't tried this myself so maybe it will work. I do know that devices like mixers and that Shure adapter cable use a transformer to eliminate the hum you will get from trying to use a balanced cable like an unbalanced cable.

There's a good explanation of how a balanced cable works on this web site but it doesn't go into what will happen if you don't use a transformer when connecting a balanced cable to an unbalanced cable. I just know what I've heard on the subject from various places. I didn't really try to find proof of the problem here and for all I know the method described here by allan may work just fine.

In fact I'm not sure what is meant by a "transformer" that is used by mixers etc. to convert to an unbalanced line. The method described by Allan might be exactly what those "transformers" are actually doing. I didn't understand the use of the metal film resistors in Allans description so I'm really not sure of anything here. I just know what I've read but I don't have the technical knowledge to know the details. If someone does know I'd like to hear an explanation of what the "transformers" used in mixers etc. are actually doing.

Edited January 7, 2007 by King Ghidora

[AllanH]

That's the way I have understood the problem ozpeter. But I've never tried to make a cable directly connecting the balanced pins to an unbalanced cable as was suggested. The stuff I've read about it says you will get hum if you try it but since I haven't done it myself I can't really say for sure. I think the idea is that you get interference from the side of the balanced signal that you don't use. The longer your cable the more likely you'll hear interference because after all you have essentially two unbalanced signals side by side using the same ground in a balanced cable setup. Yes you can use one channel or the other but you will have about the worst possible situation going for a cable. You will have another cable running right with your signal carrying cable from one end to the other. You just stand a very good chance of picking up interference.

But like I say I haven't tried this myself so maybe it will work. I do know that devices like mixers and that Shure adapter cable use a transformer to eliminate the hum you will get from trying to use a balanced cable like an unbalanced cable.

There's a good explanation of how a balanced cable works on this web site but it doesn't go into what will happen if you don't use a transformer when connecting a balanced cable to an unbalanced cable. I just know what I've heard on the subject from various places. I didn't really try to find proof of the problem here and for all I know the method described here by allan may work just fine.

In fact I'm not sure what is meant by a "transformer" that is used by mixers etc. to convert to an unbalanced line. The method described by Allan might be exactly what those "transformers" are actually doing. I didn't understand the use of the metal film resistors in Allans description so I'm really not sure of anything here. I just know what I've read but I don't have the technical knowledge to know the details. If someone does know I'd like to hear an explanation of what the "transformers" used in mixers etc. are actually doing.

Re: metal film resistors. I was once advised that adding the resistors was the 'proper' way to unbalanced the signal. (Metal film because these are the lowest noise). Doesn't seem to do any harm. However, method also works if pin 3 and 5 are connected directly to pin1 (ie no resistors).

I have successsfully used this approach with >100m balanced cable between the phantom power supply and the microphones, with only 1m between the output of the phantom power unit and the HiMD recorder.

AllanH