balanced or unbalanced?

H

hrchris

New member
I finally got my new emu 1212M soundcard working under linux. I hooked up a cable from one of the soundcard OUTs to a TRS adaptor to take the signal to the stereo 1/8" PC speaker system (one stereo 1/8" plug goes to the simple PC spkr system which separates L and R to respective spkrs). I did this just to hear if sound was finally coming out (which it was!). Now I would like to hook up to my unpowered YSM-1 speakers. I don't have a proper amplifier yet (I will get one, but I don't buy anything until I fully understand why I need it). I just want to go from the balanced OUTs of the emu 1212M to the "LINE IN/CD" (RCA) ports on the back of an old Panasonic RX-C46 boombox, then that boombox's spkr outs to the speakers. There's a talented guy in our little town who can make me whatever cables I need. What I need to know is whether or not the "LINE IN/CD" ports on the RX-C46 are balanced (I hope), stereo (wouldn't make sense), or simply L and R mono halves of the stereo whole (which I fear is the case). Is there even such thing as balanced RCA ports? I actually kept the original "Operating Instructions" booklet that came with the new (years ago) boom box. Surprisingly it does not indicate whether these INs are balanced or unbalanced. Can anyone enlighten me?

Chris
 
RCA connections are never balanced.

You need three connections to be balanced, rca only has two.

You will be just fine with an unbalanced connection until you get a proper setup.
 
Thanks for the information. I was afraid that I might short out the emu 1212M if I put a TS plug into each of it's TRS balanced OUTs. So, you think I'll be okay except I won't get the noise reduction that would come with using TRSs to take the balanced signal to balanced INs of a proper amp?

Chris
 
Two things happen. First, you're signal won't be noisy, you just won't be able to have cables (NOT mic cables) over ten feet long or they become susceptable to EMI (hum). The second is the level will drop about 6dB by unbalancing. No big deal.
 
Track Rat said:
Two things happen.
Click to expand...

Actually you brought up three things.

Track Rat said:
First, you're signal won't be noisy,
Click to expand...

True. Unbalanced signals are not necessarily noisier than balanced ones. On a certain level, it could be argued that an unbalanced signal is purer, as it passes through less circuitry. But often the reduction in noise is worth it.

Track Rat said:
you just won't be able to have cables (NOT mic cables) over ten feet long or they become susceptable to EMI (hum).
Click to expand...

You may be thinking of the limitation of high-impedance cables like guitar cables, which must be kept short to limit degradation from capacitative rolloff. EMI and RF can get into a cable of any length.

Track Rat said:
The second is the level will drop about 6dB by unbalancing. No big deal.
Click to expand...

Maybe. That depends on the gear involved. Servo-balanced gear, like that offered by Aphex, and suprisingly, much of the Behringer line, does not lose 6db when switching from balanced to unbalanced. Neither does anything transformer balanced or impedance balanced. The only circuit that loses 6db is the very common electronically balanced circuit seen on about 90% of the gear out there, most likely including the Emu 1212M.
 
related questions

Hello friends,

I have a few related questions. First, just what is the difference between balanced and unbalanced? I'm aware that balanced is 3 and unbalanced 2. What does the extra connection do? How do you know when to use what?

Second, I'm about to purchase a Parasound 2125 amp for use with monitoring and composing. A friend can get me home audiophile gear at cost, and has recommended I use this type of amp in my studio. This amp (along with all other home audio gear) uses RCA connections. Why is it that audiophile home audio uses RCA, but pro-sound gear uses phono? Is this going to be a problem when integrating this amp in with my other equipment?
 
Hello friends,

I have a few related questions. First, just what is the difference between balanced and unbalanced?

# I just learned this. It will be good practise to explain it, though it will be more in their application than the heavy technical stuff. A TRS is A TRS is a TRS - three connectors (Tip, Ring, Sleeve). If the port it is plugged into is "stereo" then the connectors are used for L signal, R signal and ground. Like cheap PC speaker systems that take both signals down one cable from a PC where it is pluggd into the soundcard via 1/8" plug. There, one cable and one port uses TRS for stereo (not balanced).

# Balanced is when you have two balanced (using the three connectors not for L and R, but this time for L or R. The noise in the other two connectors are out of phase and thus mostly cancel each other out. So, for balanced, you have noise-free L going from one cable, and noise-free R going down another cable. Some htink that, depending on a few factors, balanced can give you as much as 6dB more signal than unbalanced.

# Stereo gives you noisy L and R going down the same cable. So, stereo is about L and R. Balanced is about noise reduction and more signal. Stereo is about L and R through one port/cable.

Chris

I'm aware that balanced is 3 and unbalanced 2. What does the extra connection do? How do you know when to use what?

# From the specs. Or when it is obvious (RCA is unbalnced; soundcard with two line outs must be balanced, I would think). That sort of thing.

Chris

Second, I'm about to purchase a Parasound 2125 amp for use with monitoring and composing. A friend can get me home audiophile gear at cost, and has recommended I use this type of amp in my studio. This amp (along with all other home audio gear) uses RCA connections. Why is it that audiophile home audio uses RCA, but pro-sound gear uses phono?

# Maybe it's S/PDIF.

Is this going to be a problem when integrating this amp in with my other equipment?

# Hopefully someone else can help with this part.

Chris
 
wait, the guitar "cables" themselves aren't necessarily high impedance are they?

Isn't it just that the guitar pickups themselves expect to see a high impedance at the input of their amplifying device?
 
pipelineaudio said:
wait, the guitar "cables" themselves aren't necessarily high impedance are they?

Isn't it just that the guitar pickups themselves expect to see a high impedance at the input of their amplifying device?
Click to expand...

Yes, thanks. And the pickups have high output impedance as well. The cable itself has basically no impedance at audio frequencies.
 
hrchris said:
Hello friends,

I have a few related questions. First, just what is the difference between balanced and unbalanced?
Click to expand...

It seems like you have a pretty good start on this already.

hrchris said:
# I just learned this. It will be good practise to explain it, though it will be more in their application than the heavy technical stuff. A TRS is A TRS is a TRS - three connectors (Tip, Ring, Sleeve). If the port it is plugged into is "stereo" then the connectors are used for L signal, R signal and ground. Like cheap PC speaker systems that take both signals down one cable from a PC where it is pluggd into the soundcard via 1/8" plug. There, one cable and one port uses TRS for stereo (not balanced).
Click to expand...
Yup.

hrchris said:
# Balanced is when you have two balanced (using the three connectors not for L and R, but this time for L or R. The noise in the other two connectors are out of phase and thus mostly cancel each other out. So, for balanced, you have noise-free L going from one cable, and noise-free R going down another cable. Some htink that, depending on a few factors, balanced can give you as much as 6dB more signal than unbalanced.
Click to expand...

Pretty much. The 6db thing depends on the design of the gear.

hrchris said:
# Stereo gives you noisy L and R going down the same cable. So, stereo is about L and R. Balanced is about noise reduction and more signal. Stereo is about L and R through one port/cable.
Click to expand...

Not necessarily noisy. Is your home stereo noisy? More susceptible to noise is the way to think of it. And stereo doesn't have to be a part of it. There are mono balanced and unbalanced circuits as well.

And while in a stereo headphone TRS jack L and R share a common ground wire, in stereo RCAs they do not. So L and R would be considered to be separate cables, each carrying an unbalanced signal.



hrchris said:
I'm aware that balanced is 3 and unbalanced 2. What does the extra connection do? How do you know when to use what?

# From the specs. Or when it is obvious (RCA is unbalnced; soundcard with two line outs must be balanced, I would think). That sort of thing.
Click to expand...

The extra connection is the shield. The cable has two conductors wrapped in a shield. The shield is connected to the sleeve, which is connected to ground. Any noise picked up by the shield therefore has a path to ground. On XLR connectors, pin 1 is the shield.

If the gear uses balanced ins and outs, use balanced. If it doesn't, don't. And if your system isn't noisy, don't stress about unbalanced connections.

hrchris said:
Second, I'm about to purchase a Parasound 2125 amp for use with monitoring and composing. A friend can get me home audiophile gear at cost, and has recommended I use this type of amp in my studio. This amp (along with all other home audio gear) uses RCA connections. Why is it that audiophile home audio uses RCA, but pro-sound gear uses phono? Is this going to be a problem when integrating this amp in with my other equipment?
Click to expand...

RCA connections are smaller and cheaper. If all your gear is running unbalanced anyway, using phono plugs just costs money for no benefit, if you are the manufacturer.

Just use adapters or cables with the right connectors, you'll be fine.
 
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