Hey guys, I am trying to build a Digital to Analog converter using a USB sound card. Basically, I somehow wire this circuit to a USB sound card ( Before the filter caps on it). Could someone help me as to where each output/input goes?
Basically it takes in the signal from a USB sound card, amplifies it, then shoots it back out at about a +5/-5 signal (I think).

I am just having props as to which input/output goes where.

Thanks

EDIT: Oh, it would help if I attached the diagram

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With this inverting amp, you have one input and one output. The input is to R1 and the output is at U1A.1. Is this the DAC you were referring to? USB is not digital but a differential signal. I'm just trying to understand what you are trying to do here.

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Well, its basically just to get the digital signals from the computer, and convert it to analog. The USB does the converting part, all i need to do is amplify it. The trick is I have to bypass the filtering caps on the output.

I gather that the Vcc on the op-amp goes to the Vcc at the 15V? and the Vdd goes to the - of the 15V?

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The zener diode in your circuit does not limit the output of the opamp to only plus and minus 5.1V. It biases the inverting input so the output of the opamp is from -14V to almost 0V and is never positive.

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The zener diode is there to provide a -5V reference. It can be replaced with a -5V reguator. The reason it is needed is that sound cards are single-supply so the sound card chip output typically rests at 2.3V, and full on is 4V and full off is 0.6V.

So, with DC coupling you must set the offset pot (r3) to counter the 2.3V DC offset (so the output is 0V), then set the gain pot (r4) to reach +/-5V during hard clipping.

each tl072 has two op amps in it, you can add more for more channels of DAC up to 8 (for an 8 channel sound card)