Repurposing AV receiver as Amplifier

[DubPlate]

I have an old Onkyo TX-SR604 that I would like to repurpose as a amplifier for surrounds and atmos channels. The 604 has DVD multichannel in (7.1). The manual says the only sound mound for multichannel in is analog pcm, which I think is essentially a pass through.

My current setup is a processor with an amp for the front three channels.

My questions are:

(1) are there any major drawbacks to using a receiver as an amp?

(2) what level should should the volume knob be set at on the 604 if using as am amp?

(3) I assume the trims on the 604 should all be set at the same level, and perhaps slightly on the negative side?

Thanks in advance

 

[Swerd]

The DVD multichannel inputs on your 604 seem to be meant for line level analog audio inputs directly from a DVD or Bluray player with an internal DAC and similar multichannel outputs. I don't know whether this can work with preamp level signals, although I think it might. Line level signals are typically in the 100-200 mV range, and preamp level signals are somewhat stronger, in the 0.5 to 1 Volt range, if I remember correctly.

How are you planning to hook this up? Will the signals go directly from your disc player to the Onkyo? Or will they go from the disc player, through your preamp/processor, and then to the Onkyo? How you do this will determine which volume knob (preamp/processor or Onkyo) controls those channels.

You'll have to experiment with the volume controls to see what works. Start at very low volume and increase slowly.

Onkyo TX-SR604 Manual
http://www.intl.onkyo.com/downloads/manuals/pdf/tx-sr674_604_manual_e.pdf

 

[DubPlate]

The DVD multichannel inputs on your 604 seem to be meant for line level analog audio inputs directly from a DVD or Bluray player with an internal DAC and similar multichannel outputs. I don't know whether this can work with preamp level signals, although I think it might. Line level signals are typically in the 100-200 mV range, and preamp level signals are somewhat stronger, in the 0.5 to 1 Volt range, if I remember correctly.

How are you planning to hook this up? Will the signals go directly from your disc player to the Onkyo? Or will they go from the disc player, through your preamp/processor, and then to the Onkyo? How you do this will determine which volume knob (preamp/processor or Onkyo) controls those channels.

You'll have to experiment with the volume controls to see what works. Start at very low volume and increase slowly.

Onkyo TX-SR604 Manual
http://www.intl.onkyo.com/downloads/manuals/pdf/tx-sr674_604_manual_e.pdf

Thanks Swerd, I hadn't thought about the voltage issue. My plan is to hook the source into the preamp, and from there to the 604.

 

[BMXTRIX]

If volume control is handled by the preamp, then it is sending line level out and you may connect to any of the 7 inputs on the Onkyo.

Onkyo volume should be set to 0dB.

All volume control will be from the preamp.

This will work just fine. You will not have any voltage issues. Do not plan on playing things too loud and give the Onkyo lots of room to breathe.