piggy-back op-amps

[amc32]

I can remember reading an article in ametuer audio some years back.About the advantages and dis-advantages of parrelleling op-amps(piggy-back).I cant recall the meat of the article.So I decided to bring it up here at diy-audio.

Any takers?

 

[Perry Babin]

For audio, there's probably no advantage. Having the outputs of the stacked op-amps directly connected would likely lead to instability and significant distortion.

 

[amc32]

ARe there any non audio purposes for doing this.
And what about the increase in signal strenght,reduced distortion,if it modded to be stabalized.

 

[Perry Babin]

If you were going to use the op-amps as part of a low current voltage regulator or to drive a high impedance speaker of some sort, stacking them could be useful but the circuit would have to be well damped. Having a small resistor in series with each output would also help improve stability.

I don't think there is any advantage of stacking them for audio. MANY years ago, there may have been a need for it but the op-amps available today are much better and stacking them is not likely to be useful.

Questions like this are often difficult to answer definitively because there are so many variables. Asking how an op-amp will behave is like asking how a random person will behave in a random situation.

 

[john65b]

If the merits of stacking 8 pin DAC Chips (like Kusinoki's 4x TDA1543 DAC) are so prominent (tried it myself and definitely notice a SQ difference), why not opamps?

I asked this questions months ago and got no reply...

 

[Eva]

Op-amps work in a completely different way. Direct paralleling (like placing two DIP8 ICs one over another) results in overheating and potential destruction.

You can't drink any transparent liquid just because water is good for you 🙂

 

[amc32]

I'm going to dig-up that old ameture audio magazine,I'll back with this one