Hybrid system - experimenting and learning

mdaudioguy

I'm slowly building my "dedicated" stereo rig that also happens to function as a 5.1 HT, and learned something this weekend. The HT is run by a slimline Marantz AVR that has front pre-outs only. The pre-outs run to a Marantz integrated amp that had been set to power amp direct mode (aka home theater bypass), so in that configuration, my Squeezebox Touch feeds the AVR a digital stereo signal, and the AVR is a preamp with DAC, sending an analog signal to the amp.

Yesterday, I changed things up a little by turning off power amp direct mode and using the full function of the integrated amp for stereo listening. In this configuration, the SBT, using its own DAC, feeds an analog signal directly to the integrated amp. Wow, the difference was not slight! What I once thought sounded pretty decent (using the AVR as a pre), is no longer palatable. Even though the SBT DAC is probably inferior to the much newer Marantz AVR DAC, it seems the preamp stage of the integrated is considerably improved. More punch, more dynamics, more stereo separation - just plain better.

The next step will likely be the HD-DAC1, to improve on the SBT DAC. There will have to be some experimentation with this configuration, too, because the HD-DAC1 can also function as a preamp. So... I'll see about that when I get there.

Anyhow, I'm very pleased so far with this arrangement. The default plan is to leave the integrated in power amp direct mode for me and the fam to enjoy TV with surround, but when I really want to enjoy my music, I can easily switch over at the touch of a button.

nooshinjohn

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mlistens03

Very interesting. I’ve never seen a “power amp mode” on a integrated before. Very nice, and keep us posted with updates!

mdaudioguy

This was a good resource.
http://audiophile.no/en/articles-tests-reviews/item/426-amplifiers-with-processor-input

mhardy6647

once upon a time separable power & preamps in integrated (stereo) amplifiers was a fairly common feature, but the driver for including such a feature in those ancient times was somewhat different.

Here's a somewhat random example - note the "pre-out"/"main-in" jumpers on this Superscope-era Marantz 1060 (borrowed photo).

mpitogo

I think you got it right but check to see if you can use some sort of trigger for HT bypass on your Marantz integrated.

HT bypass is fairly common on two channel integrated or pre-amplifiers. My Atmos 7.2.2 also doubles as a 2.0. In my case the AVR has a 12v trigger which goes into my integrated amps home theater bypass. The HT bypass trigger powers on the integrated amp and overrides the manual controls. The input is selectable between rca or balanced, since my AVR’s front left right only has RCA preouts I have it plugged into the RCA aux jack on the integrated. When the AVR powers on it puts the integrated amp in HT bypass much like a dedicated two channel amp with fixed gain. The benefits are, 1) the L/R have it’s own dedicated Amp relieving the AVR (but is fully integrated with Atmos and is also calibrated with Audyssey) 2) In two channel the integrated amp and accompanying speakers are unhindered by the superfluous audio and video processing in the AVR. Not to say that the AVR is not musical but, integrated is more suited to music.

The 2.0 is in a way independent, the music source(s) are dedicated to it, while the video sources go into the AVR. Both can’t run at the same time.

nooshinjohn

I have been very happy with my setup. I also run a hybrid system, and I have found the key to pulling it off well is to invest in a preamp of exceptional quality. I also suggest excellent amplification for the mains, allowing the amp within the receiver do the work for the other speakers.

Bad news in my setup is that I am using tube amps for my mains, and when watching a movie, they are being wasted. If you go solid state, that will be less if a problem. My rig is used 80% music and 20% movies/tv... though for tv, I do not bother turning on the mains most of the time.