How to connect a power amp to my existing Onkyo TX-NR545?

[William Lemmerhirt]

That is crazily (Onkyo) confusing and they should not label it as pre-out if it is just a line out. Good thing the op is careful otherwise he may risk damaging something.

Totally agree. My Onkyo and Marantz have had zone 2 pre outs so indeed they had zone2 volume functionality. Not sure about my Yamahas or pioneer.

 

[PENG]

So what you are saying is to still use the 2 Zone2 outputs as intended? And yes, you are right. I do have a level adjust on the NAD. Interesting!
Correct me if I am wrong but there is no possibility I can damage my NAD by simply testing this setup, using the line out interfaces on my AV, right?

Correct, you won't damage the NAD if you switch the input level to variable and set it to minimum before turning it on.

Then if there is no sound or sounds very quiet then you are all set, and can try gradually turning it up, that is, use it as vol control. If that works well, you should tape the switch with a warning like "do not touch', to minimize the chance of damaging your speakers.

 

[lovinthehd]

What is typical line level, tho? 200mV? I suppose you could damage the speaker (wouldn't think the amp particularly tho) depending what the source level was....

 

[lovinthehd]

To be fully clear, I do have a NAD pre-amp (C510) that I can use for the purpose of what I am looking to do but this specific pre-amp lacks built in connectivity. This is why I started digging into whether or not I could use my existing avr as a pre-amp and the reason why I started this thread. But yes, my avr appears to lack the full set of pre-outs.

The setup I would have to go with in that case is to use my NAD C510 together with the NAD C275BEE.

Gotcha. Sometimes modern gear has advantages Why I use avrs.

 

[PENG]

What is typical line level, tho? 200mV? I suppose you could damage the speaker (wouldn't think the amp particularly tho) depending what the source level was....

I think it varies a lot and I would guess 1 to 2V at rated distortions for AVRs. My DVD3310 output well over 2 V. As you alluded to it depends on the source output, i.e. program contents.

 

[lovinthehd]

I think it varies a lot and I would guess 1 to 2V at rated distortions for AVRs. My DVD3310 output well over 2 V. As you alluded to it depends on the source output, i.e. program contents.

Manual says its 100mV (and 1V for the sub pre-out). Still as you say it depends on what you're feeding it and better safe than sorry thus my original caution.

 

[PENG]

Manual says its 100mV (and 1V for the sub pre-out). Still as you say it depends on what you're feeding it and better safe than sorry thus my original caution.

If it is only 100 mV then it would have to go through an active preamp for most applications. As you know there is no way 100 mV can drive the C275 to it's rated output, not even close..

Edit: you got me curious because 100 mV seems very low, so I downloaded the manual, not that I didn't take your words for it..

It says 100 mV/2.3 kOhm, so if the input impedance of the C275 is 20 kOhm like many power amps are, the Onkyo may be good for 1 V. If not, even 0.5 V may be enough for the op. That is assuming the Onkyo's line out buffer is current limited but not voltage limited to 100 mV. I can't know that for sure, but it seems like a reasonable assumption.

 

[lovinthehd]

If it is only 100 mV then it would have to go through an active preamp for most applications. As you know there is no way 100 mV can drive the C275 to it's rated output, not even close..

Edit: you got me curious so I downloaded the manual, not that I didn't take your words for it..

It says 100 mV/2.3 kOhm, so if the input impedance of the C275 is 20 kOhm like many power amps are, the Onkyo may be good for 1 V. If not, even 0.5 V may be enough for the op. That is assuming the Onkyo's line out buffer is current limited but not voltage limited to 100 mV.

All in all just an odd zone 2 provision for external amps, altho if you just want to use zone 2 to record something....

 

[PENG]

All in all just an odd zone 2 provision for external amps, altho if you just want to use zone 2 to record something....

Good think I did say "I would guess.........", now we know why the Onkyo manual say "..........pre-main amplifier...". That's probably poor translation for preamp+amplifier or integrated amplifier..

For the sake of curiosity, I may measure the line out of my AV8801 that is in one of my 2 channel system and is easily accessible.