A differential input works on the difference between the inputs. Any noise induced into both wires (the "hot" and "earth" on the source, "+" and "-" on the inputs) gets cancelled as long as the cable is symmetric.
On a balanced setup you have 3 wires connecting equipment. Hot, cold and ground, IE signal, polarity switched signal and ground.
It almost seems like you are suggesting one should connect gnd to either hot or cold input and the unbalanced signal to the other?
That does not sound like a good solution to me, not with a circuit designed for balanced connection.
If you are talking about using a differential input opamp together with a unbalanced signal only, yes you can do that. But then you are not using the same circuit, and you do not get the same benefits.
You can connect the unbalanced signal to either hot or cold, and gnd to gnd, but not much noise cancelling.
It almost seems like you are suggesting one should connect gnd to either hot or cold input and the unbalanced signal to the other?
That does not sound like a good solution to me, not with a circuit designed for balanced connection.
If you are talking about using a differential input opamp together with a unbalanced signal only, yes you can do that. But then you are not using the same circuit, and you do not get the same benefits.
You can connect the unbalanced signal to either hot or cold, and gnd to gnd, but not much noise cancelling.
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Yes and no. You have two wires conducting the signal. Ground can be connected or not, it doesn't matter for the signal. The signal is not referenced to ground.
Yes, exactly. That is how a differential input works.
I suggest looking at connection #17 in this: Rane Note 110: Sound System Interconnection - AVW
You get almost all of the benefits if the cable (connection) is balanced. There will be an impedance unbalance that will make it less than perfect, but still almost as good as with a symmetric source.
There's also this:
RANE Commercial - Knowledge Base
"Balanced and unbalanced systems are not designed to interface together directly."
If you want to quote Rane notes, I advise you to link to the Rane knowledge base instead.
Here's Ranenote 110 again:
RANE Commercial - Knowledge Base
They sum it up like so:
Connecting the wires as you suggest can be done, but it is not recommended in any way.
Edit:
RANE Commercial - Knowledge Base
"Balanced and unbalanced systems are not designed to interface together directly."
If you want to quote Rane notes, I advise you to link to the Rane knowledge base instead.
Here's Ranenote 110 again:
RANE Commercial - Knowledge Base
They sum it up like so:
Connecting the wires as you suggest can be done, but it is not recommended in any way.
Edit:
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Indeed. Have a look at connection diagram #17.
A really good explanation is the classic The G Word, or How to Get Your Audio off the Ground by Bruno Putzeys.
I suggest you fire up your favourite circuit simulator and verify it for yourself.
hmm, I have always made my cables according to Hypex: https://www.hypex.nl/img/upload/doc/an_wp/AN_Legacy_pin_1_problems.pdf
chapter 4.5
Connection 17 seems the shield to be floating floating. Or am I missing something?
I will just file this away under "possible but sub optimal solutions", keep using my fully balanced setup as-is, and move on.
From Ranenote 110:
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They are kind of the same thing - the hypex document also shows the shielding should only be directly connected to chassis ground at one end, not both. You are OK connecting both ends if the source has ground lifted, otherwise the Hypex RF "filter" of capacitor/resistor is a good idea.
Is it possible to add a volume knob to Fusionamp / MP-DSP? We have a J15 plug for IR receiver. Is it possible to make a volume knob for it? I didn't find any documentation on pin 2 data format.
There is a pin 1 for some kind of output. Is there any information on its values? Can we get current volume from it?
There is a pin 1 for some kind of output. Is there any information on its values? Can we get current volume from it?
I´d like to add some stuff, maybe it´s redundant here and there:
- "noise canceling" with balanced signal transport does not do anything to get rid of noise in the signal. It only helps to keeps away externally introduced faults to a minimum like interference from other cables, unwanted potential shift, etc.. So in Case you don´t experience any hum/hiss/krickles in your system which come from the cabling - there is no need for balanced transmission in terms of Sound quality. The signal quality by itself is not superior from unbalanced signal processing.
- Differences in the ground potential can introduce "hum" (50 or 60Hz). If the signal is completely uncoupled from the mass-potential (which CAN be the case when running symmetrical), you have no risk of getting a humming noise. Connecting equipment with different ground potentials with non-symmetrical CAN lead to hum.
- Cables, the longer they get, act like antennas - distortion introduced from this also can be minimized with symmetrical cabling..
- Capacitive effects also can be more of an issue with unsymmetrical - but not within 1m cable length - if you get problems here - change the cable
There are many "little helper" devices out there to take care of some of the unwanted scenarios - starting from simple ground lift, having better shielding on cables, do double shielding, using transformers in inputs, connecting grounds together, etc..
- the voltage levels on symmetrical and non-symmetrical often differ - sometimes people refer to "PA-Level" and "hifi-Level" - Hifi being much lower.
If you are using your gear for public stuff, move it a lot, have a lot of meters to cover with your cable, lots of combinations of different gear, sometimes rented, unknown... THEN you really should go for symmetrical Connections.
But if you connect two devices together which are only a few cm apart and if the built one solid unity which isn´t changed when used (like mounting a DSP in an Amp) - and if input/output levels match - there really is no need for symmetrical.. (Levels have to match in any case, using differential signals doesn't solve this on its own - lots of gear out there with adjustable output levels to cope with this...).
- "noise canceling" with balanced signal transport does not do anything to get rid of noise in the signal. It only helps to keeps away externally introduced faults to a minimum like interference from other cables, unwanted potential shift, etc.. So in Case you don´t experience any hum/hiss/krickles in your system which come from the cabling - there is no need for balanced transmission in terms of Sound quality. The signal quality by itself is not superior from unbalanced signal processing.
- Differences in the ground potential can introduce "hum" (50 or 60Hz). If the signal is completely uncoupled from the mass-potential (which CAN be the case when running symmetrical), you have no risk of getting a humming noise. Connecting equipment with different ground potentials with non-symmetrical CAN lead to hum.
- Cables, the longer they get, act like antennas - distortion introduced from this also can be minimized with symmetrical cabling..
- Capacitive effects also can be more of an issue with unsymmetrical - but not within 1m cable length - if you get problems here - change the cable
There are many "little helper" devices out there to take care of some of the unwanted scenarios - starting from simple ground lift, having better shielding on cables, do double shielding, using transformers in inputs, connecting grounds together, etc..
- the voltage levels on symmetrical and non-symmetrical often differ - sometimes people refer to "PA-Level" and "hifi-Level" - Hifi being much lower.
If you are using your gear for public stuff, move it a lot, have a lot of meters to cover with your cable, lots of combinations of different gear, sometimes rented, unknown... THEN you really should go for symmetrical Connections.
But if you connect two devices together which are only a few cm apart and if the built one solid unity which isn´t changed when used (like mounting a DSP in an Amp) - and if input/output levels match - there really is no need for symmetrical.. (Levels have to match in any case, using differential signals doesn't solve this on its own - lots of gear out there with adjustable output levels to cope with this...).
Had a flash inside FA122 module today (saw it through back cover). An apartment fuse unplugged and I left with two modules instead of 3 I had before.
Don't know what went wrong with it – didn't make any changes for a week or so and listened to speakers today for about an hour.
Got 3 modules on March 7. Since then one optical port stopped working and now one module is dead. Probably, a bad batch.
Don't know what went wrong with it – didn't make any changes for a week or so and listened to speakers today for about an hour.
Got 3 modules on March 7. Since then one optical port stopped working and now one module is dead. Probably, a bad batch.
I am currently trying to export EQ filters from REW into a Hypex fusion. I have a text file with 20 filters on it (generic output filter.) The fusion only accepts 14.
1) Is there a way to set REW to create a max of 14 EQ filters?
Is there an easier way to do this rather than manually copy over the text?
1) Is there a way to set REW to create a max of 14 EQ filters?
Is there an easier way to do this rather than manually copy over the text?
Simply, don't set your target settings so strict in REW. Just loosen it until you get 14 points or less. But hey, there are additional 9 point in the EQ section with the Fusions, although this would affect all the amp channels not just specific.
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I will shortly be borrowing one of these for a play with a view to buying for my 3 way centre.
Just wondered what the easiest or best way of using HFD is. I've been having a play with the software and it seems ok. Are people doing most things in REW, re measuring, verifying what the filters are doing exactly, and so on. Or are the measuring functions inside HFD any good for the basics. Haven't got one yet obviously so can't comment. Just trying to get a plan of action ready for when I get it in the next week or two.
Also I've yet to see any used ones come up for sale which is a good sign but money is tight so used would be good so I can do my LCR. Anyone seen any used ones sold in Europe/ on here on the classifieds yet?
Just wondered what the easiest or best way of using HFD is. I've been having a play with the software and it seems ok. Are people doing most things in REW, re measuring, verifying what the filters are doing exactly, and so on. Or are the measuring functions inside HFD any good for the basics. Haven't got one yet obviously so can't comment. Just trying to get a plan of action ready for when I get it in the next week or two.
Also I've yet to see any used ones come up for sale which is a good sign but money is tight so used would be good so I can do my LCR. Anyone seen any used ones sold in Europe/ on here on the classifieds yet?