as an example, I was looking at a pic of a Burson preamp/headphone amp.
There seems to be 4 "banks" of circuit for each signal for a fully balanced output?
Thank you.
(I believe the 4 trimmer pots is for the main circuit)
There seems to be 4 "banks" of circuit for each signal for a fully balanced output?
Thank you.
(I believe the 4 trimmer pots is for the main circuit)
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Well the black plastic sockets are XLR, which is 3-pin and almost always? always? means balanced.
Just because you have balanced inputs and output connectors doesn't mean the circuitry in between is balanced.
Go to Passlabs website and look at the Aleph P and Zen circuits and you will see the + and - signals handled by two sides of a circuit.
Fully balanced circuits have several advantages and are worth the extra parts to implement.
Go to Passlabs website and look at the Aleph P and Zen circuits and you will see the + and - signals handled by two sides of a circuit.
Fully balanced circuits have several advantages and are worth the extra parts to implement.
but in relation to the pic I included, would you say the preamp output is fully balanced?
Your’s is not as simple a question as it might seem. First, when you say balanced, do you refer to fully differential internal signal circuitry, or do you refer to signal interconnection that rejects ground (common-mode) noise, such as those utilizing XLR connectors?
the manufacturer advertizes that the device has a fully balanced output.
I guessing this means R+/R- and L+/L-. to my noob knowledge/experience, seeing 4 circuits of each of the R/L signal would mean a balanced circuit/output?
I doubt you'd be able to tell without a schematic (and the ability to interpret the schematic). Also note that there are many definitions of "fully balanced" and most of them are rooted in marketing.
Tom
Tom
So, just looking at a pic doesn't really tell me much about the actual circuit, makes for fun guessing, but I need to see a schematic to see the circuit topology.
Basically, yes. It would be near impossible to tell whether a circuit is truly balanced/differential or if it's pseudo-balanced, for example. And by pseudo-balanced I mean that the circuit consists of two halves, operating in opposite phase, whose outputs are summed at the end.
I'm curious which advantages you see in a fully balanced circuit, by the way.
Tom
I'm curious which advantages you see in a fully balanced circuit, by the way.
Tom
Noise rejection. You don't use the ground as output but a complementary circuit which hopefully is symmetric so the common noise is cancelled.
Same thing with the cabling.
Note that, so far as I know, there are no "audiophile balanced" interconnects. They are not really needed.
Au contraire. 'Audiophile' balanced interconnects do exist. Did you really doubt it? Some priced as high as you might image , some priced much more reasonably.
Okay, then you mean for the purpose of ground-noise rejection.
When an interconnection is referred to as balanced, what that indicates is that each of the signal phases has the same impedance to signal-ground. So, for example, both the R+ and R- output conductors might feature, say, a 110 ohm impedance to signal-ground. Although, it does not have to be that particular value, just so long as they are the same value.
While an unbalanced interconnection's output might feature a 110 ohm impedance to signal-ground from it's center-conductor (R+ or L+), but 0 ohms impedance to signal-ground from it's outer conductor (R- or L-). The description of an interconnection being balanced, or unbalanced, has to do with whether the two signal conductors have the same impedance to signal-ground or not.
The balanced output impedance value is usually specified in an owners manual, which then means that it is, in fact, balanced. Else, I suggest that you simply contact Burson to have them confirm. Is there some reason why you doubt Burson's claim that the output is balanced?
External noise cancellation at the input, a greater possibly gain through the gain section, depending on design of course, and noise cancellation in the circuit in the form of distortions, that is, harmonic distortions can be cancelled at the output by circuit design.
There is a simple test to confirm balanced inputs or outputs.
Connect an RCA cable between pin 1-2 and pin 1-3. Do You hear sound on both connections?
On a pseudo balanced connection, the pin 1-3 connection test doesn't pass sound.
Ken is right, balanced has to do with equal impedances and not with signal on both wires (pins 2 & 3 or Tip Ring on a Jack).
Many cheap mixers work this way, and bear in mind the simple classic op-amp balanced input found on 90% of the gear has unequal impedances on its inputs because of the feedback resistor interaction.
Connect an RCA cable between pin 1-2 and pin 1-3. Do You hear sound on both connections?
On a pseudo balanced connection, the pin 1-3 connection test doesn't pass sound.
Ken is right, balanced has to do with equal impedances and not with signal on both wires (pins 2 & 3 or Tip Ring on a Jack).
Many cheap mixers work this way, and bear in mind the simple classic op-amp balanced input found on 90% of the gear has unequal impedances on its inputs because of the feedback resistor interaction.
But you can get those advantages with a balanced input (driven by a balanced source). The circuit following the differential receiver does not need to be balanced.
Tom
And I'd like to add that a balanced connection with its advantages does not need to be symmetric.
A balanced connection with signal on only one line can be perfectly balanced and work great at cancelling common mode noise.
Jan
A balanced connection with signal on only one line can be perfectly balanced and work great at cancelling common mode noise.
Jan
Like a phono cart output. Balanced without being symmetrical.
The same is obviously true for transformers too. Interestingly i have tested this in practice with a transformer coupled preamp fed to a balanced power amp input. Electrically could not find any difference between using the transformer center tap or not. Sonically, the difference was profound.
The same is obviously true for transformers too. Interestingly i have tested this in practice with a transformer coupled preamp fed to a balanced power amp input. Electrically could not find any difference between using the transformer center tap or not. Sonically, the difference was profound.