Stacking the Stellar M700s

So I’ve pulled the trigger to get a set of three M700’s to pair with a S300 for my hybrid 2-channel/HT setup. The monoblocks would go with the front and center channels and the rears with the S300. This would replace my beloved Mcintosh MC205. I’ve come to realize I’m losing a little in dynamics and ultimate clarity with the Mac and am confident the Stellar stack will remedy the situation. The problem I have now, apart from having to buy another three power cables (!), is how to fit them in my rack. The bottom shelf in my custom made rack has about 14 1/4 inches top to bottom to accommodate the stellars. I think I could fit all four in the slot but that would necessitate stacking all four in the slot, which honestly gives me hives just thinking about. I may be able to fit my Nordost Sort Kones under the stack, which may ameliorate some of the vibration problems I assume will come about with stacking them. Still, am I setting myself up for disappointment by stacking them like this? Is stacking two all I should try to do? There’s no was I can give each their own shelf. I don’t have space for that. I might be able to configure a custom slip shelf to split the space of 14" into two 6.5" spaces and stack the Stellars in twos. It would be tight, though, and I couldn’t use the Nordost Kones. So there’s that. Thoughts?

I have my Stellar GCD and S300 stacked and have heard no difference. I think the rubberized feet on the product absorb very well. More so than the cheap plastic feet on on other devices.

amgradmd said

So I’ve pulled the trigger to get a set of three M700’s to pair with a S300 for my hybrid 2-channel/HT setup.


I can’t comment on the stacking question but I like the way you roll @amgradmd !

I stack two M700’s with no problem using just the feet they were born with. They don’t run hot and I wouldn’t think stacking more than two would be a problem.

BigAlMc said

I can’t comment on the stacking question but I like the way you roll @amgradmd !


Thanks, Big Al! I think this one of the only ways I could make a significant upgrade to both the 2-channel and HT setups. Honestly upgrading the HT portion will be lost on my family. My wife doesn’t like loud music or HT and my 13 and 15 year old girls think their iPhones sound great!

Regardless, I’m pretty excited. Since my local shop didn’t have a pair of M700 to lend me, I borrowed the next best thing - a Classe Sigma 2200i class D integrated. As it turns out, Darren Myers had a big hand in designing and voicing that amp when he was with Classe. I thought it sounded great, if a little lean in the bass which I thought was because it was running through the DSP tailored for my McIntosh. Very strong dynamics. I did notice that there wasn’t a problem with extension of upper frequencies at all. In fact, if anything, I was getting too much treble with the overall sound a little on the colder side, which Darren acknowledged were issues. Darren has said that the M700 has none of the problems of the 2200i. In his words from an email exchange, “The truth is that the amp section (of the Classe) is already outdated and does not have the latest tech in it. In the S300 and M700, there is a dual feedback path that compensates for the issues of the low pass filter and therefore interacts with the speaker less. This makes the amp sound more like a traditional linear amplifier…with a boat load of headroom!”

So there you have it. Mine hopefully will arrive this week. I’ll keep ya’ll posted!

Adam

I literally just finished swapping an S300 for a pair of M700. I don’t have the horizontal space to set them side by side. My options are stack or offset stacked so they overlap about 2".

Is the purported ‘sounding better’ from isolating respective vibrations or from physical separation of the transformers or other internal components?

My guess is separating the amps keeps them from electrically interfering with each other, but recognizing vibration control can make a tremendous difference as well.

Thanks Elk, I guess like so many things, it depends. I’ll try them both ways.

It may be illustrative to try them stacked with the top one at 90 degrees, 180 degrees, etc. to see if the sound changes. If so, the benefit of separation is most likely electrical isolation.

Unfortunately, I’m space limited in my chosen location, inside a nice wood ‘AV’ credenza. It’s 1" too narrow to run side-side.

I’ll let them run in for a few weeks, along with new BHK Pre and then experiment. I’m only able to stack directly on top, or offset them side to side with a small over lap but I can go bottom one right, top left or bottom left, top right. I suspect the torroids field will interact with one another more than anything else.

BHK Pre is about 3" above the stack of M700s. All my gear is hidden except for speakers.

What do people think about placing these wooden blocks between the M700?

I bet it would work fine but it’s pricey. It says a bundle, people says it either 1 or 2 blocks. Bamboo is far cheaper.

Here’s what I managed. Supports are redwood 4x4 cut to length. I’ve got a little bit of Sorbathane under each of the 4 contact points so that both amps are ‘floating’. The visible redwood will get a shot a flat black and disappear, the camera makes them stand out.

Sounded great before, will need a few days to listen, but it certainly isn’t worse. The preamp getting cold was a bummer, took a couple hours to get it back to sounding as it should.

Keep in mind basswood is very soft. Generally hard woods are used for this purpose; e.g., Cardas’ myrtle wood blocks.

I have my SGCD on top of my S300. SGCD is on Orea Indigo isolators.

I just experimented with adding a layer of ERS paper in between the Stellars and I can hear a benefit. Keep in mind I also put the paper on the top and bottom of my FMC’s, on the bottom of my Ultrarendu, and on top of my two smps’s.
WiFi is turned off.

I have my SGCD and M700 monos stacked with DiversiTech E.V.A. (Extreme Vibration Attenuation) anti-vibration 2x2x7/8 pads under each foot. The only thing about these pads is it takes a while for the strong rubber smell to fade.

“My guess is separating the amps keeps them from electrically interfering with each other, but recognizing vibration control can make a tremendous difference as well.”

If the M700 is designed in such a way that stacking them on top of each other can audibly degrade the sound quality, why are they shown stacked in every picture on the PS Audio site?