[reaction]

Hello,

I am just finishing my home opamp-based headphone amp and I think to add a pair of RCA outputs directly wired to the inputs because my CD player is a source for my loudspeaker system too.

So, has anybody tried this sort of wiring? Does it perform some negative effects to the sound – I mean more capacitance, lower input signal voltage or weak signal to my integrated amplifier? Or I should take the signal to my phone amp from the integrated amp’s REC or PRE outs?

Thank you.

 

[tangent]

From a theory standpoint, you should be able to wire the "loop through" outputs directly inline with the inputs because the opamp has a very high input impedance and your speaker system's amp probably does, too. In the ideal world, both impedances are infinite, which means you can drive them with zero current. In the real world, it means the impedances are merely very high so you need very little current to drive them. So, your source -- the CD player or the preamp it's hooked through -- should be able to drive both amps easily. In fact, that's one of the preamp's jobs: to decouple the sources from the amp, in case there's a high-load device farther down the chain.

All that having been said, I've never done this and am also interested to know how this works out in the real world. I've been half-tempted on occasion to open up my Creek OBH-11 or -14 and trace the circuits to see how they pull this trick off so I can add it to my amps, too.

 

[rickcr42]

Well I do this very thing all the time and it depends.I usually take my feed from the tape out of my preamp so that means the headphone amp sees the output impedance of the "source" componant.
The "through" jacks then go to a recorder.Unless the tape output is buffered you could end up with some strange interactions unless the recorder is on even though not being used.
In your situation you seem to be taking the output from the main preamp out.If this is a solid state unit and the amps all have a high impedance in put it should be fine.But if the preamp is tubed based and the output is a high impedance you may encounter some signal degradation.
All you can do is try it and compare,maybe add a temporary bypass switch in a box for testing