XLR and 1/4''

[musicandmeaning]

I'm just getting started with recording with real equipment, so please take this in mind when you answer my question.

Let's say I have a mic pre with 8 XLR outputs, and an interface going to my computer that has 6 1/4'' inputs and 2 XLR inputs. Could I get around this by buying XLR-->1/4'' cables? Would that compromise my tone? What would you suggest I do?

Thank you for your time

 

[bennychico11]

yep, that's what you need

 

[MadAudio]

What exactly is your interface? There are two kinds of XLR to 1/4" cables: balanced and unbalanced. If the 1/4" inputs on your soundcard are balanced, then...

 

[Big Kenny]

make sure they are trs 1/4"

'

 

[PhilGood]

By TRS, Big Kenny means "tip-ring-sleeve". Think of a guitar cable and you only see a sleeve and the tip on the connector. The sleeve is the sheid as well as signal. On a TRS connector, there will be an extra ring in between them (hence the name). Here the sleeve is only the ground and the ring and tip are signal. TRS are balanced and TS are unbalanced. Some mixers and inputs are capable of detecting which is being used. Check your hardware manual to find out if your unit does this. If it only uses unbalanced on the 1/4" inputs, you will need to use impedance matching transformers.

 

[mshilarious]

If it only uses unbalanced on the 1/4" inputs, you will need to use impedance matching transformers.

That's not true, there is no impedance mismatch. Use the same TRS cable, you'll just have an unbalanced connection.

 

[PhilGood]

That's not true, there is no impedance mismatch. Use the same TRS cable, you'll just have an unbalanced connection.

Where do you get that?! 1/4 Unbalanced inputs usually expect a high impedance connection. As a rule XLR means balanced, low impedance audio lower than 600 ohms. Unbalanced audio is generaly higher, 1000-5000 ohms and as much as 10,000 ohms. Why do you think we use direct boxes? They convert unbalanced, high impedance signals to low impedance, balanced XLR. Sure, the preamp is going to output low impedance signal, but if the input is high impedance, the signal will be useless!

 

[Farview]

. Why do you think we use direct boxes?

To bring line level signals down to mic level.
In this instance, you would be going from a line level source to a line level input. It should be good. Don't confuse the connector wth the type of signal it carries.

 

[Richard Monroe]

PhilGood- There are more than one type of balanced and unbalanced inputs and outputs. Tip sleeve cables can be shielded, as in instrument and patch cables, or unshielded, as in speaker cables. Unbalanced connections can be multiple impedences. You are confusing an unbalanced 1/4" connection with a high-z or instrument 1/4" input, as you would plug a guitar into. Today, most 1/4" inputs will accept balanced or unbalanced connections. Line out to line in good.-Richie

 

[mshilarious]

Where do you get that?! 1/4 Unbalanced inputs usually expect a high impedance connection. As a rule XLR means balanced, low impedance audio lower than 600 ohms. Unbalanced audio is generaly higher, 1000-5000 ohms and as much as 10,000 ohms. Why do you think we use direct boxes? They convert unbalanced, high impedance signals to low impedance, balanced XLR. Sure, the preamp is going to output low impedance signal, but if the input is high impedance, the signal will be useless!

Well preamps always have low impedance outs relative to line inputs . . .

First, we should distinguish between various types of inputs: mic, instrument, and line. Mic inputs typically are something like 2K ohms, and are balanced XLR. Instrument level inputs are TS 1/4", and have a much higher input impedance, like 1M ohms. If you want to send an instrument into a mic input, then yes, you need a direct box.

But the OP didn't ask about those, he asked about line level in/outs. Those are typically 10K ohms input impedance whether balanced or unbalanced. If you send a balanced out into an unbalanced in, you chuck half the signal to ground, but that is no big deal, just a 3dB loss.

Yes, you could put a transformer in front of the interface to maintain the balanced connection, but it isn't the same trafo you'd use for the DI, and for a short cable run in a studio, it isn't necessary. At any rate, it would be fairly expensive for 8 channels.

 

[PhilGood]

That IS very true, you're right! Although to me sending a 200ohm signal up a 10kohm path would result in signal degradation, wouldn't it? I mean HALF the signal?! That seems like alot of loss of fidelity. What about floor noise? That increases as well if you pump the signal. (although for home recording, what the hey! I'm not going to get too uptight about it.)

God I love this forum!! It's so great to get valuable knowledge like this. Don't worry about stepping on MY toes! If I'm wrong, I'm wrong and I'll be wiser for it.

 

[mshilarious]

That IS very true, you're right! Although to me sending a 200ohm signal up a 10kohm path would result in signal degradation, wouldn't it?

No, that's the way it's intended to work.

I mean HALF the signal?! That seems like alot of loss of fidelity.

Not half the signal "detail", half the amplitude. All the signal detail is present in both + and -. There is no loss in fidelity, just 3dB of level.

What about floor noise? That increases as well if you pump the signal. (although for home recording, what the hey! I'm not going to get too uptight about it.)

It could, plus you might pick up some line noise due to the unbalanced connection. Unbalanced inputs are usually found on lower end gear anyway.

 

[PhilGood]

Got it! Very cool!