Ayre amplifier to Subwoofer connections


I am trying this question again with a more specific title to try to get responses . . .

I am intending to hook an Ayre, fully balanced amplifier to a subwoofer via the high level (speaker) inputs. Ayre has told me NOT to connect negative to black but to chassis ground. A balanced amplifier cannot be connected to anything with a common ground.

The subwoofer amplifier manufacterer (O-Audio) says the plate amplifier has no common ground by virtue of the fact that it only connects 2 prongs to the outlet.

I have also heard that other audiogoner's have connected Ayres to subs via the red and black speaker connections without a problem. How have you accomplished this?

Can anyone explain to me in more detail what is up with this technically and what connections I should be using.

Additionally, can you tell me the pros and cons of connecting the speaker leads to the sub from the speakers vs the amp. Does it have to do with length, noise, etc?

thanks to everyone in advance!
drewh1
Drubin- It sounds like Al helped you figure this out. Ayre did not give very complete instructions.

FYI- you can't use tape out for subwoofer output because it is a fixed output and not connected through the volume control.

Al -

no offense taken - I am glad it did not seem to have any ill effects. I guess since I connected each black to different screws on the plate amp, there was enough resistance to prevent a dead short. At any rate - the amp is the best that I have heard so far and I really do feel that the speaker connections to sub amp provide a better subwoofer integration than the pre-outs. This has been suggested in other places in this forum.

Hope everyone is enjoying some music on this beautiful Sunday morning (here in sunny CA).

drew.
Revisiting this topic, one of the downsides of the chassis ground connection scheme, at least with my REL, is that when the Ayre is turned off but the REL left on, the REL hums. Drewh1, do you experience the same thing?
Drubin,

I am not using this scheme. After researching, I determined that the only way that a ground connect failure could occur is for the subwoofer amp to fail and short everything to ground. Since my O-audio subwoofer amp does not have a common ground connection, I am hooking both negative and positive leads as normal as this is a very remote possibility. Also the O-audio is a digital amp. I do know of someone else using Ayre with Martin Logan subs who connects both Pos and Neg terminals and has no problems.

You must determine that your amp does not have a common ground connection. It may not be enough to simply lift the common ground from the plug if you have one. The amp I have did not have a three prong plug, only two.

This doesn't directly answer your question, I know but may give you an alternative connection.

drew.
Interesting. The REL has a three-prong plug. I will say that I think the system sounds better connected the standard way (i.e., not to chassis ground), but that may be the 6db volume difference at work. I don't want to blow up the Ayre of course, but...
I have a new question on this subject. How do you connect a stereo pair of subwoofers to a fully balanced stereo amp, such as the Ayre.? The REL cable for each sub has two channels of "hot" (red and yellow) plus a ground. I assume that, for each sub, you would connect both hots (or just one?) to the plus side of the appropriate channel on the amp. But what about the grounds? Would you connect both subs' grounds to the chassis?