hey, im looking to build my own balanced dac to feed a kgsshv that i am also planning on building, but seeing that the topping D10 is only 120$, are there kits/designs that could possibly beat it at a lower\simliar cost?
Pick any DAC you like
Add XLR to chassis
Make sure the output impedances are the same on both hot and cold pins of the XLR
And it's balanced.
Add XLR to chassis
Make sure the output impedances are the same on both hot and cold pins of the XLR
And it's balanced.
Of course!
What grounds? In a balanced link, there is no ground, that's the whole point! There is positive, negative, and shield. And the signal is the difference between positive and negative wires. Each channel (left, right...) can have its own positive and negative, without any of them being "ground"... The balanced receiver does a substraction.
To make a balanced output on gear that doesn't have one, the positive pin of the XLR goes to the existing signal output, and the negative pin goes to a ground point on the board that is the closest thing to the 0V reference of the signal. If it's a DAC board with an opamp IV, the bets place would be the point that the output opamp thinks is "0V", on the arrow:
The most important thing is that the impedances in series with the two wires must be equal, otherwise that lowers the common mode rejection (the substraction) in the receiver and noise is not remove as it should. In the above schematic, the opamp driving the RCA has a 100R resistor in series, so you'd neglect the output impedance of the opamp and put the same 100R in series with the negative wire.
A true balanced symmetrical output has two opamps, one outputs the inverted signal, so it has double voltage swing and therefore +6dB SNR. But besides that, actually having an inverted signal is not necessary for the most desirable property of balanced connection, which is noise rejection and no more ground loop headaches...
The shield should go to the metal box.
If I ask for about building a balanced dac to feed the balanced input of my headphone amp, I wouldn't take too kindly to being fobbed off with a mickey mouse answer.
Misunderstanding going on here? It can be done right with practically the same amount of work when a balanced DAC chip is used in the device.
As an example, if I found the Topping D10s acceptable I would replace the phono connectors with a pair of mini XLRs and add a balanced driver inside.
"budget" and "valves" when the OP mentions a 109 Euro costing 103 x 146 x 37 mm DAC. That is quite a difference, sorry.
It really is simpler/cheaper/smaller to modify the output stage of the D10s to true balanced .....as I think OP wants good sound quality and maybe even best possible sound quality.
It really is simpler/cheaper/smaller to modify the output stage of the D10s to true balanced .....as I think OP wants good sound quality and maybe even best possible sound quality.
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Wonder why I suggested a cheap mod and not a custom mezzanine PCB with a pair of THAT1646 on it...
Small balancing trafo is all you need. You can go fancy with expensive one, or cheap. Easy peasy.