Op-Amp recommendation for replacing/upgrading I/V and LPF in a dac

[kazuviking]

Hello there. I have a cheap chinese dac (D2-mini) and wanna experiment with different op-amps. Currently it uses 2 NE5532P as the I/V and a TL072 as the LPF.
Current planned replacement NJM2137D for the I/V and AD8066ADR for the LPF. The LME49720NA is disqualified as the LPF because its 5V performance is horrible, 1%thd+n at 2vrms output. I'm looking for any op-amp recommendation that is not super expensive.
Dac internals.

 

[dreamth]

I'd say your main problem seems to be the supply voltage...look for professional soundcards that work at 5v if you ca find any snd just copy their choices or supply it properly first! Another cheap choice would be njm8080 working at +-2v which is used in Audient gear but there are many opamps working down to 1.5V supply .

 

[davidsrsb]

Neither the NE5532 or the TL072 are any good at 5V. Are you sure about that as I can see what looks like a DC/DC top left.

 

[Zoji6645]

OPA2156 @ 5V is 0 to 5V on both Input and Output

 

[kazuviking]

Neither the NE5532 or the TL072 are any good at 5V. Are you sure about that as I can see what looks like a DC/DC top left

Im an idiot. Measured it and its 22V

 

[kazuviking]

I'm and idiot, forgot the measure the voltage, its 22V so probably its +-11V .

 

[dreamth]

That's good cause now you have a huge range of op amps to choose from...I'd suggest google online pcb photos of RME ADI-2 or Focusrite Scarlett...if you want following industry's standards.

 

[JMFahey]

Problem is that at +/-11V supply I very much doubt you have 1% distortion.

You didn´t measure it, only guessed based on a wrong supply assumption.

In a nutshell, you are looking for a solution to a non problem.

 

[kazuviking]

Problem is that at +/-11V supply I very much doubt you have 1% distortion.

You didn´t measure it, only guessed based on a wrong supply assumption.

In a nutshell, you are looking for a solution to a non problem.

The LM49720 part was from the datasheet before measuring the voltage inside the dac.