Adding Center Channel

The Marantz is used to drive only the center channel and isn't connected to my preamp. I had it connected as follows: from projector to Marantz via HDMI, from Marantz to Oppo via HDMI, Oppo to my preamp via Optical cable. My DAC is connected to my preamp via  balanced cables.

Sync problem is being caused by your connections. You have created two different signal paths for the 3 speakers.

Oppo HDMI output > Marantz > Center Speaker

Oppo Optical output > DAC > Preamp > Amp > L&R Speaker

The issue is not using different amps, but using 2 different outputs on the Oppo. Both amps must receive a signal from a single output.

What is the right way to connect it?

Hi Ric,

You don't have it connected properly for a combo 2-channel/HT add-on system.

You need to connect the L&R line level RCA cable from the Oppo to your pre-amp for listening to 2-channel music.

You need to connect the Oppo to your HT receiver using an HDMI cable.

You will need to connect the center channel speaker to the center channel speaker output of the HT receiver.

You will need to connect the L&R front speaker pre-outs on the receiver to your HT input on your pre-amp.

Once you do this you will need to engage the HT bypass on your 2-channel pre-amp when you want to listen to multi-channel output from your Oppo player.

You will also need to go through the setup sequence on your HT receiver to tell it you have X number of speakers (3?) and set up the speaker balance (probably automated using a MIC).

If you run into any issue with this, let me know. I would be happy to help. I've done this type of combo system many times with good success, but I always used the HT receiver to power the center channel and the L&R rear surround speaker.

Enjoy,

TIC

Connect the Marantz front preouts to the HT bypass input on the preamp. Then when you select that input, the Marantz VC controls volume on all speakers. Even though sound quality of L&R may not be quite as good as before, the sync problem should be eliminated.