Acoustats and D-class amps ok together?

[lotones]

I'm about to upgrade my system and have been leaning towards getting a rmb-1077 to replace my Carver 705x. My concern is a blurb in the "Details" box of the Hi-FI News review of the 1077 from the Rotel site which says:

"Each amplifier has it's own pair or 4mm speaker terminals, but both red and black are floating so you should never connect them to a grounded loudspeaker"

The Acoustats have a transformer behind each panel that needs to be plugged in, so does this mean the 1077 shouldn't be used with the Acoustats? The dealer with the 1077 wasn't sure and is willing to let me demo the 1077, but I don't want to chance blowing the amp or my speakers without knowing more first.

thanks...

[kmcheng]

I say call and email Rotel directly...

[mjb]

What they mean is the ground from say the front left channel is NOT the same as the ground from any other, and so the grounds are not (and should not) be connected together - they're not "common", and not connected to ground.

So, if the ground lug from your speaker finds itself connected to the the ground lug of the other one (via a power cord through the house wiring for example), hooking up the 1077 would probably damage something in it as the non-common 1077 output grounds would be joined.

[lotones]

kmcheng - looks like I'll have to do that.

mjb - so you're saying don't even try it? 8O lol... glad I asked first...

Thanks for the replies, guys...

[JoeESP9]

I'm about to upgrade my system and have been leaning towards getting a rmb-1077 to replace my Carver 705x. My concern is a blurb in the "Details" box of the Hi-FI News review of the 1077 from the Rotel site which says:

"Each amplifier has it's own pair or 4mm speaker terminals, but both red and black are floating so you should never connect them to a grounded loudspeaker"

The Acoustats have a transformer behind each panel that needs to be plugged in, so does this mean the 1077 shouldn't be used with the Acoustats? The dealer with the 1077 wasn't sure and is willing to let me demo the 1077, but I don't want to chance blowing the amp or my speakers without knowing more first.

thanks...

lotones:
The interface boxes on Acoustats have no effect on floating output connectors. ESL's have a power supply to energize the grid. The diaphragm is transformer coupled to the input signal. There is no ground anywhere in the signal path. I have 2 pair of Acoustats, Spectra 22's and Model 1's. They are the third and fourth pair of Acoustats I've had.
If you like I'll dig out a schematic I have of the MK (they are all very similar) series power supplies. I will send an attachment when I find it.
I realize I'm jumping in out of the blue here. Look me up on

https://www.audioreview.com

www.audiokarma.org

https://www.stereophile.com

I am JoeESP9 everywhere but Stereophile I'm JoeE there

[lotones]

JoeE, that's good news because I was really looking forward to hearing the Acoustats (mine are model 3M) with the 1077. I was just going to give it a shot and stand by with a fire extinguisher... 8O just kidding...

thanks a lot for the response and for sharing the knowledge.

[Amphiprion]

You can use a multimeter and check to be sure that the speaker cable connections on the Acoustats are floating relative to the ground prong on a wall outlet. If Joe's info is correct you should be fine.

[lotones]

You can use a multimeter and check to be sure that the speaker cable connections on the Acoustats are floating relative to the ground prong on a wall outlet. If Joe's info is correct you should be fine.

Thanks, I'll keep that in mind.