HEOS app
HEOS app, streaming music from network server

Sharing inputs

But HEOS also has one feature which, I’m fairly sure, remains unique to it. That feature lets you play any source connected to any HEOS device to any other speaker or zone. Right now I am listening to The Steve Miller Band’s album Abracadabra from a 35-year-old vinyl recording through the Marantz M-CR612.

But, you might say, the Marantz doesn’t have phono inputs, does it? No, it doesn’t. Nor does my turntable have a built-in phono pre-amplifier … er, hang on a moment. Vinyl being what it is, that album finished. Now Cha by Jo-Jo Zep and the Falcons is playing. Try finding that on Spotify or TIDAL. Anyway, no, my turntable doesn’t have a phono pre-amp (I do own a couple, but I’m not using them). No, the turntable is plugged into a Denon home theatre receiver which does have a phono input. And it also works with HEOS. So, the Denon is sending the music across the network to the Marantz unit.

The connection turned out to be a little flaky with the Marantz M-CR612 connected wirelessly. It was probably due to the thick soup of 2.4GHz and 5GHz signals with which my office is filled. I plugged the Marantz into Ethernet and it worked perfectly.

HEOS app
With HEOS you can pick inputs from any connected device

Talking to the Marantz M-CR612

HEOS stuff, and therefore the Marantz M-CR612, is controllable by voice using both Alexa and Google Assistant. You can do things like skip tracks, switch the unit on and off, increase and lower the volume or mute the unit. You can tell it to play music from some Internet services.

In both cases, you’ll need to jump through the system hoops of enabling HEOS control for Alexa or Google Assistant. The former had me bamboozled for a while because Alexa wasn’t objecting to most commands, but neither was she doing anything in response. It turned out that I’d previously associated a different Marantz device with her and its name lingered on. Alexa was interpreting the commands as intended for it.

So, it was just a matter of updating the devices and then she started working properly. The functionality for Alexa and Google Assistant was much the same. You can do things like set to volume to an absolute level by number or increase or lower it. “Alexa, turn up the volume on Marantz” increased it by five decibels.

HEOS app
… including, of course, a turntable

Streaming music by voice

Oddly, neither Alexa nor Google Assistant would play Spotify content to the unit, even though it is Spotify Connect-capable, and even though the unit appears in the list of speakers in the Spotify app on my phone as a speaker to which I can send Spotify sound. HEOS-equipped devices were recently given the ability to play Spotify without a premium subscription, so I guess it’s possible that there are bugs associated with that change.

The Marantz M-CR612 is not equipped with microphones so it can’t hear you. You need to have some Alexa (or Google Assistant) device handy to speak to in order to make it do things. I have an Echo Dot (and Google Home Mini) in my office for the purpose.


The Marantz M-CR612 was a delight to use. It worked quickly and well with network music from my server – both using the HEOS app and using my usual DLNA app. It worked well with streaming music, including TIDAL and Spotify. I plugged in a large portable hard drive carrying a duplicate of all my music and found it easy to navigate through its contents for playback using the HEOS app. It played back most of my high-resolution stuff, including 24 bit, 192kHz FLAC files, Direct Stream Digital and DSD128.

And of course, it played back my CDs.

I used it with a pair of KEF R300 loudspeakers. They are largish bookshelf-sized models with very competent bass down to 40 hertz. They sounded brilliant, especially when I advanced the volume to room-filling levels. There was plenty of power to drive them.

Subwoofer and headphones

There is a subwoofer output, although this wasn’t configurable so I figure that it wouldn’t stop bass going to the main speakers. There are also line level outputs – you can set their output level to “fixed” if you want – so you can either add your own amplifier or active speakers, or just use the unit as a source for some other audio system.

I measured the 3.5mm headphone output. It’s capable of delivering almost 100mW undistorted into highish impedance (300 ohm) headphones, and 55mW into lowish (16 ohm) headphones. Both of those will provide more than ample levels for almost all headphones and earphones. However, the output impedance of the headphone connection was around 75 ohms. For technical reasons we won’t go into here, that will affect the frequency balance of some headphones. Which ones and how much? That’s the big unknown because the information about headphones needed to assess that is rarely published.

While I prefer to see headphone output impedances to be two ohms or less, I will note that Marantz has reduced this figure markedly of late. Some of its recent devices had output impedances of 450 or more ohms, which is much more problematic.


The Marantz M-CR612 is a mature and highly effective all-in-one playback system for 2019. And one with unexpectedly advance features, such as voice control (so long as you have a suitable Alexa or Google Assistant device to talk to) and multiroom support. If you want a neat, effective and fine sounding system, check it out.