biamplification wiring how-to

Tripper,

I also have NAD power amps in a second system that are bridged mono. I found that by far the best sound IMHO was achieved by isolating right and left channels. No splitter used in this configuration. The L and R fixed level preamp outputs are each connected to the left channel input of a power amp. This is required when operating in bridged mono mode. One power amp is then connected with a pair of matched speaker cables to the left speaker (one run to the +/- bass connections and the other to the +/- treble connections). Same thing for right speaker with the other amp. This gives complete channel separation and provides plenty of clean power.

Dan-ed Hi
No actually I haven't try active yet,but for sure I will one day.Bryston's Active crossovers are very well regarded.My Aerial 10T have very nice build in crossovers though.Perhaps my current set-up is a compromise, can't say for sure.I am experimenting and upgrading as my budget allows,also life gets in the way sometimes with our audiophile hobby,I think.Years ago I bought a new pair of JBL L7 speakers,they came with a nice manual by JBL.It was in that manual that I first read about bi-amping with four tubed monoblocks or two tubed monoblocks for mids/highs and solid state monoblocks for lows.My Mark Levinson is in fact a dual mono power-amp .In it's manual Madrigal cautions that a performance of the 27.5 degrades slightly when user turns the amp into monoblock configuration.I believe this holds for other high-end amps as well.Unless they are made true monoblocks from factory.I got a CJ MV55 as well and years back I wrote to Conrad Johnson regarding turning the amp into monoblock they told me that it wasn't a great idea but they could do if I insisted.
I didn't do it.
Both amps sound great as they are.That is why I bought my Rogue M150's since they are true monoblocks ,I use then as they were intented.
Best
George

Hi George,

I have 10t's as well so I'm very interested in your bi-amping experiments. I have been trying to find tube and SS amps that have gains and input impedances that match well enough to not use an external x-over. BAT amps usually come to mind but the Rogues are looking like another option here. I have not been able to find any gain specs on the M-150's so I'm hoping you'll know. The Levinson 27.5 looks to have a 26 dB gain which is a better match with some tube amps like the BATs. The Classe's I'm using have 29 dB gain so they may not match up well without the use of a x-over or I may have to swap them out with something else. As you know the 10t's like alot of power so I agree that the bi-amping is a great way to go. And the tube amp on top and SS on the bottom is great way to get that tube sound short of using 4 high powered tube amps.

I found the same thing about running stereo amps in bridged mode. Classe said it was fine to do. But I found that they weren't as smooth and ran hotter. I believe that there is also an issue with the load that the amp sees. In bridge mode an 4 ohm load looks like 2, and so forth. I agree, true mono-blocks are preferable.

I'll have to check out the Bryston x-overs. I couldn't find a Marchand that had balance connections.