How to connect a balanced pre with an unbalanced recorder?

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antispatula

antispatula

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I've got an unbalanced reel to reel recorder. Even if you aren't familiar with reel to reels, the idea is simple. The recorders ins and outs are XLR. So I want to run a mic and preamp directly into the back. The pre is balanced of course, so

how do I go about connecting a balanced preamp to an unbalanced recorder?

I've never really gotten balanced and unblanced.....I get the idea, but that's about it.

Is it a DI box I need? Don't know.

Thanks so much!!!!!
 
Just plug the preamp into the recorder. You have an Otari MX5050, right? Double check, I think the inputs on that are Pin 3 hot (meaning Pin 3 of the XLR input receives the positive signal). You'd just need a cable that sends the positive output of your preamp to the positive pin on your recorder's input. Going from balanced to unbalanced shouldn't do anything to your signal other than a 6dB loss in volume.
 
woah really? Sweet! Ok, rewiring to pin 3 hot is easy enough. Thanks!

Then why is there such a fuss about interconnecting the two? Is it unbalanced to balanced that gets your signal messed up, or what? I don't get any of this...... :cool:
 
Couldn't tell ya. My mixer's buss outputs are on unbalanced Pin 3 hot XLRs (would be perfect to match up with a MX5050, which I'll hopefully have one day), and the inputs on my HD24 are balanced. I don't have any problems there. I also don't have any problem running my HD24's balanced outputs to my mixer's balanced line inputs using unbalanced cables.

The only time I ever had a negative effect was using an XLR to 1/4" TS (unbalanced) cable to plug my SansAmp into my Echo Layla. That would hum when I did that. I suspect, though, that it might have something to do with the fact that the cable ran very close to a CRT computer monitor. The problem went away when I bought a Mogami XLR-TRS balanced cable.

If you do get hum issues, you could seek out a balancing transformer like something from Lundahl or something.
 
If your machine has XLR connectors, then how can it be unbalanced? My Tascam 38 is unbalanced and has RCA connectors.
 
XLR is just a style of connector. True, the vast majority of XLR connectors are balanced, but not always. Like I said, my console has its buss outputs on unbalanced XLRs. Only two of the pins are connected, Pins 1 (ground) and 3 (positive) in my case.
 
and to make sure my xlr's on the machine are balanced, could I check the internal wiring: If all three pins are connected on the inside, they're balanced?
 
I couldn't tell you about that, as I don't have that kind of knowledge. I would say that its not necessarily true, as the unused pin could be shorted to ground.

You might want to dig up some documentation on the MX5050. I think they're unbalanced, but I'm not sure.
 
antispatula said:
Then why is there such a fuss about interconnecting the two? Is it unbalanced to balanced that gets your signal messed up, or what? I don't get any of this...... :cool:
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Potential hum, noise, and damage. Some balanced outputs will fry if for instance pin 1&3 are shorted on the outputs (wired together), which I see commonly recommended.

I find that if a piece has special hookup needs, they are usually laid out in the manual.
 
woah, so I've heard that A it's no big deal and B It'll fry my machine......uh, what should I do?!
 
antispatula said:
woah, so I've heard that A it's no big deal and B It'll fry my machine......uh, what should I do?!
Click to expand...

It probably won't fry it. You can always hook up balanced and unbalanced gear. It's just that some gear has restrictions, which like I said will be most likely laid out in the manual. If no special diagrams are given, pretty much any of the recommended wirings will work. One or another may give you better results in terms of noise.
 
unbalanced xlr...

from what I understand the MX-5050 is unbalanced XLR.

check this out.

anywayz I've connected about 4 different preamps, both low and high end, into my unbalanced E-16, without doing anything special, and never had a problem. I think the idea of swapping pins 2 and 3 might be a good one though, if you do run into problems. I can't believe that there isn't a multi-channel transformer based-converter on the market because I am almost at my wits end with this particular problem and might end up just building something. but for now I can live with a little hiss.
 
One of my outboard preamps will fry if I hook it to something unbalanced. It says so in the manual about 75 times in really big print. Check the manual, if it doesn't say anything, you are going to be fine.

Falken: There is nothing wrong with using unbalanced connections. Balanced connections just stop your cable from picking up transmission noise. That is generally a hum, not a hiss. If your cables are not 50 feet long and running across the back of your TV and you don't live next to a radio tower, you shouldn't need balanced connections.
 
Farview said:
Falken: There is nothing wrong with using unbalanced connections. Balanced connections just stop your cable from picking up transmission noise. That is generally a hum, not a hiss. If your cables are not 50 feet long and running across the back of your TV and you don't live next to a radio tower, you shouldn't need balanced connections.
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I'm with you here...

for the most part I have no problems....

although; to use a reel-to-reel you pretty much have to have a patch bay...so you have a 9-foot cable going to the bay and then another 9-foot cable going to the board; its tough to get your cable length under 15' when you are using a bay.....but the worst noise is generated when I go back out of the mixer using a group out or something (say for vocals) to go into a compressor (another 10') and back (another 10').... although the group outputs are balanced and the compressor is balanced, for some reason when I feed the mixer an unbalanced signal that's all I get out of the group out. When I finish building my rack mixer its going to have transformers on freaking everything....

which pre is it that will blow if you use it with an unbalanced connection?
 
I've never seen or read anything about potential damage to balanced connections from tying pins together on the unbalanced end. Thanks for pointing it, guys, I'll definitely keep it in mind.

Antispatula, my apologies for not giving you entirely correct info.
 
FALKEN said:
I can't believe that there isn't a multi-channel transformer based-converter on the market
Click to expand...

Ebtech makes an 8 channel Hum Eliminator in a 1RU setup. I believe its nothing more than some balancing transformers in a rackmount box.
 
Antistipulata and I have been discussing our MX-5050 mkIII woes and I have a question about hooking it up to my patchbay. The Otari is unbalanced XLR ins and outs, and my patchbay is balanced 1/4" so when I build my snake, so I use TS or TRS ends?
 
ADATlove said:
Antistipulata and I have been discussing our MX-5050 mkIII woes and I have a question about hooking it up to my patchbay. The Otari is unbalanced XLR ins and outs, and my patchbay is balanced 1/4" so when I build my snake, so I use TS or TRS ends?
Click to expand...
It doesn't matter. For future use, I would make a balanced snake. If you get rid of the Otari in favor of something else in the future, your snake will still be useful.
 
Farview has the right idea there. Build with future possibilities in mind. However, since the Otari is pin 3 hot that means it still can't be built totally normal. Unless of course your console and preamps are also pin 3 hot:)
 
xstatic said:
Farview has the right idea there. Build with future possibilities in mind. However, since the Otari is pin 3 hot that means it still can't be built totally normal. Unless of course your console and preamps are also pin 3 hot:)
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It still wouldn't make a difference. If everything is 180 degrees out, you will never know the difference. Besides, when it comes back to the mixer, it will right itself because it will be coming back out of pin 3.
 
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