Two examples can be Lm4562 and opa1612, both frequently used by Linn .
The stability gets better with bypassing the power using a 0.1 uF poly cap near the +V and -V pins of the op amp.
But what about the soundquality ? Will it always be better or maybe worse? , making the sound more stackatto like, with less flow ? Or is this always a good thing to do ?
Im experimenting with a tpa3255 module that has two op amps before the class D chip. I will ofcourse try decoupling the OP:s to see how it sounds but I would like more opinions from experts on this matter.
What about bypassing Op amps with 0.1 uF capacitor at +V and -V pin ?
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Re: What about bypassing Op amps with 0.1 uF capacitor at +V and -V pin ?
I recently did a lot of experiments myself using the tpa3255 amplifier board. Does it sound better with plastic capacitors as a decoupling near the input Op amps 1612, 4562, or is it possibly a maybe, or sometimes?
If you read electronics, you will see that the test results are often better in terms of measurement with a 0.1 uF capacitor at the op amp, the high-frequency noise seems to be lower at the same time that each capacitor causes resonances depending on the value of the capacitor.
I use tunemethod as an evaluation and an extra decoupling capacitor of 0.1 uF at +V and -V on both opa1612 and lm4562 causes a slightly worse flow in the music which tends to sound more staccato than you would like. It therefore results in a worse sound.
I have also tried using better quality capacitors with a low value in parallel with a larger electrolytic capacitor that is in series with the music signal and the result has in all cases been worse than before. It seems that it is much better to replace the entire electrolytic capacitor with a better quality one - then it will sound better in many cases. How do you know what sounds better then? Unfortunately, it is impossible to determine the quality of the capacitors by reading the datasheet or even by measuring. The price does not seem to have a huge impact either, a hint is that polypropylene capacitors in the signal path often sound better than electrolytics, but there is no guarantee that this will always be the case.
I wonder whats your experience about this ?
Edit: also found out that my amplifier card sounds best if the chassie is floating , no ground to the box.
If you read electronics, you will see that the test results are often better in terms of measurement with a 0.1 uF capacitor at the op amp, the high-frequency noise seems to be lower at the same time that each capacitor causes resonances depending on the value of the capacitor.
I use tunemethod as an evaluation and an extra decoupling capacitor of 0.1 uF at +V and -V on both opa1612 and lm4562 causes a slightly worse flow in the music which tends to sound more staccato than you would like. It therefore results in a worse sound.
I have also tried using better quality capacitors with a low value in parallel with a larger electrolytic capacitor that is in series with the music signal and the result has in all cases been worse than before. It seems that it is much better to replace the entire electrolytic capacitor with a better quality one - then it will sound better in many cases. How do you know what sounds better then? Unfortunately, it is impossible to determine the quality of the capacitors by reading the datasheet or even by measuring. The price does not seem to have a huge impact either, a hint is that polypropylene capacitors in the signal path often sound better than electrolytics, but there is no guarantee that this will always be the case.
I wonder whats your experience about this ?
Edit: also found out that my amplifier card sounds best if the chassie is floating , no ground to the box.