Some confusion connecting audio chain

In case any of you haven't gathered, I don't know what I'm doing.

Thats ok, neither do the rest of us! 😀

Starting from the Yamaha MG10/2 mixer..
MIXER (ST out with two 1/4 jacks) pigtailed to mono EQUALIZER (with option of either a single balanced 1/4 jack in, -- OR a single XLR jack in). Do I pigtail to the 1/4 jack or do I pigtail to the XLR?

Thing to keep in mind is XLR is balanced, 3 wires. Since you are using the un-balanced output on the mixer (1/4), you will want to pigtail to the un-balanced input on the equalizer (1/4). If you mix it up between un-banalced and balanced, you will end up with a nulling effect and seriously reduce the signal level as well as frequency response. Usually a balanced to un-balanced amplifier is used to mesh the two together.

From the Nady GEQ131 equalizer (mono)..
EQUALIZER (mono) pigtailed to AURAL EXCITER (stereo) which accepts two 1/4 jacks in. Same query; Do I pigtail from the equalizers single 1/4 jack or from the single XLR?

Use the 1/4 connection. Same reasons as described above for question 1.

From Aphex Dominator II 720
DOMINATOR XLR out, spliced into a to STD PASSIVE AUDIO DIVIDER/COMBINER - 10 kΩ, I've asked this before and was told the STD 10 kΩ model I purchased would work, but would like to be certain..?

Well a balanced XLR connection is low impedance while an un-balanced connection (be it 1/4, rca, mini 1/8) is high impedance. You will get results connecting that final stage up, but you will probably notice a drop in signal level at that point because of interfacing two completely different impedance levels. Again a balanced to un-balanced amplifier/buffer will solve that problem...or simply cranking up the TX audio level input to compensate. However you might end up noticing some added noise floor due to the balanced to un-balanced connections. It also opens up the barn door to other noises such as induction hum from heavy load devices, RF interference, static noises and other irritating noise artifacts, like actually hearing light switches "clicks" or light dimmer buzzing.

RFB

a balanced to un-balanced amplifier/buffer will solve that problem.

So what am I looking for? ... am I looking for a balun? Do I need several of them? This processing gear I have only gives me the option of going back and forth with balanced/unbalanced a few times as you can see, so does that mean I need a few of these buffers which you advise?
I ran google searches based on your post, but unsure of quite what I was looking for... I found this http://www.rdlnet.com/product.php?page=53 but it's rather pricey at $140, there's no way I can buy something like that right now.. are there cheaper alternatives?

I'm sorry, you spoke clearly, but I'm still unsure on exactly what it is I need. I don't want to introduce the possibility of interference of the audio as you describe.

How about this? It's only $8 http://www.amazon.com/Pyle-Pro-PDC21-Instrument-Balanced-Unbalanced/dp/tags-on-product/B0027V760M

Yes they can be a bit pricey. However you can get by with a simple balanced to un-balanced cable or adapter without the active components. They come in both a one piece unit and in a cable form. The link below is an example to a cabled XLR to 1/4 adapter.

http://www.cheapbandgear.com/25_Microphone_Cable_XLR_to_1_4_p/xlrf-14-fslash-25.htm

There are also one-piece type adapter units that are the same thing but without the cable and can be found at most musical instrument stores that also have PA and mixer gear.

Hope that helps! 🙂

RFB

Well I already have that already RF! .. But if it doesn't have the "active components", then it doesn't solve anything - right?

These work also. And are exactly like the one piece units, except they are within a box. The "passive" units have no electronics other than a simple transformer.

The only drawback to these passive balanced to un-balanced interfaces is that there is some signal level loss through them. Not a problem with the equipment you are using as all of the gear have level adjustments to compensate, the most important thing here is to properly interface the two different impedance schemes (XLR-1/4). Proper interfacing will prevent a lot of headache with unwanted noise getting into your audio chains.

Great find Rich! 🙂

RFB

It appears we are talking at the same time Mr. Burns, every time you respond to my comment, my next post shows above yours!

Well the active interface merely includes some amplification to compensate for the 600 ohm to 10k ohm impedance difference because going either direction between them will cause some signal loss, so the active components amplify and help provide some isolation. But the passive ones also provide isolation due to the transformer.

If you have these already, your good to go. All you may have to do is adjust the levels at each piece of gear to maintain the audio signal level as it goes from one gear to another through this array of balanced to un-balanced chain.

You shouldn't have any difficulties unless you got high powered RF nearby or very noisy light dimmers or a welding shop close by. Bouncing back and forth between the two different impedance schemes always brings in potential for induced noises from outside sources. But it looks like your good to go already.

Sorry if I caused some confusion...its late and my eyes are starting to blurr everthing! I put my soldering iron down just in case though! 😀

RFB

It appears we are talking at the same time Mr. Burns

LOL!! Ahh the good ol days of CB talk over! BREAK BREAK!!! 😉

Ya you should be ok with your setup. I have encountered such installations in radio and tv stations and usually get asked "why is there this annoying hiss?".

This is why its important to maintain impedance throughout the audio chain. At one point or more, you have to compensate by turning up the level, then possibly turning down the level at another. Either hiss noise or over-driving results.

If only all gear had identical interfacing, either XLR or 1/4 or both. Some do have both, and when that is present its good to stick with one impedance all the way from front to end.

Hope all works out ok! 🙂

RFB

Just a thought here...
What if I put the STD 10 kΩ audio combiner right after the mixer and before the processing chain?, and then used a single channel connections on all of the processing equipment thereafter?
Just used one side down the line?

I realize I would still be jumping from unbalanced to balance connections, but would this method do anything to lessen the potential of any nulling, noise, and lower frequency response?

What if I put the STD 10 kΩ audio combiner right after the mixer and before the processing chain?

Since the STD unit is capable of interfacing balanced and un-balanced connections in either direction, that would allow the mixer's output to become universal via the STD unit. I believe this would be the better choice of where to install the STD unit.

...and then used a single channel connections on all of the processing equipment thereafter?

Yes. Since the transmission will be mono, and this allows you to have a spare chain amongst the processing line just in case by simply swapping over to the unused channels on the processing gear. It will also let you double the processing at each point, by taking one side's output and route that back into the 2nd side's input, then out to the next stage. Of course doubling is not necessary but you can experiment with that.

By putting the STD unit at the output of the mixer, you are now standardizing the audio chain in the balanced mode all the way up to the TX input, which will greatly reduce any chances of noise and other unwanted junk getting into the audio. Keep the leads from the mixer to the STD unit as short as possible. If you have a 2nd STD unit, put that at the tail end of the audio chain and then go into the TX, further reducing chances of noise and garbage in the audio.

If you do not have a 2nd STD unit, install a 1 to 1 transformer at the input of the transmitter.

1:1 audio transformer-Radio Shack
http://www.radioshack.com/product/index.jsp?productId=2103994

RFB

Well thanks for all the help RF, and for the link.. I only have one STD unit.
I don't however comprehend the advantage of taking the processing output and feeding it right back in the other channel to be processed all over again.. But that's not something I'm currently concerned about.

Since the STD unit is capable of interfacing balanced and un-balanced connections in either direction, that would allow the mixer's output to become universal via the STD unit.

After thinking about it, this throws me off a little too, I know the STD works in either direction.. but the audio is only traveling one direction - and "the mixer output becoming universal via the STD" statement, I find the "universal" puzzling.. universal in what respect? in that its all mono?

But anyway, If this discussion has become tired, then no reply is necessary. I know it's gone on a long time in a short time span!
I appreciate the time you took answering question after question in this run, and from what I can tell the all my pressing questions concerning the connections have been answered anyway.

Not at all, glad to discuss and help. 🙂

By saying "universal" I mean that with the STD unit which can work both balanced and un-balanced, your creating a path for that mixer's output to have both the balanced and un-balanced functionality at the same time. You can run an output feed that is balanced and another output feed that is un-balanced..all at the same time instead of being limited to just the 1/4 un-balanced output.

The STD, and any other passive unit like it, allows for any of its connection points to be either an input or an output, basically like a preset mixer that uses no sliders. You can plug in two pieces of equipment's output into the STD and the STD will function as a mixer.

As to the processors looping from one output and then back to the 2nd channel input, you can expand the processing power. For example, one channel can be set for compress/expand and the 2nd can be set to limiting/gating. Basically it just gives you double the functionality in a single processor unit. Very useful if your working with audio levels that swing wildly like that found in live musical performances.

RFB

On your mixer, there should be a switch just under the input gain knob of each channel which controls the type of input which that channel preamp is to work with. But what you want is to retain the same match between your outboard components and between them and the mixer. IOW, as RFB points out, avoid connecting an unbalanced cable to a balanced input or visa-versa.

Remember, the main audio output of the board is being controlled by the channel and main faders. The preamps in the board are doing the work. Try to get the best sound when input gain and channel faders are at Unity (look for special tick marks denoting range on the knobs. The goal is to have the best response and plenty of signal without raising the noise floor

I use a recording snake between my board and the computer interface.