Looking at the owner's manual, it doesn't appear that you can bridge the RB 1080. You could sell it and buy a RB 1090. That's a MONSTER amp and sounds very good.
11 responses Add your response
As Mofi indicated, it appears that the RB-1080 cannot be bridged.
Also, be aware that an amplifier that is operated in bridged mode will "see" a load impedance equal to the speaker impedance divided by two. Like many B&W speakers, the 800D reaches impedances at some frequencies in the lower part of the spectrum that are quite low, apparently about 3.1 ohms in this case. So a bridged amplifier would see that as about 1.5 ohms. Very few bridged amplifiers will be able to handle that low an impedance with good sonic results, and some might overheat as you indicated, or go into protective shutdown mode, blow fuses, etc. I suspect that most high powered amplifiers that are capable of handling that kind of a load impedance when bridged will be quite expensive.
I'm not familiar with the model Mofi suggested, but I would choose among amplifiers that can provide adequately high power without being bridged, and that preferably have a specified continuous maximum power capability for a 4 ohm load that is twice what the rating is for an 8 ohm load.
I've been on the lunatic fringe for 3 years now with the same speakers. They are potentially great, but can be mediocre with lesser electronics, room, cabling, etc. Rotel makes good stuff for the money, but will certainly be a limiting factor in your setup. At the very least I would look at 500 watt monoblocks. Many good choices for amps depending on your budget. Its probably not the answer you were hoping for but to cut corners with amps and power is not a good idea.
Welcome to the big leagues. B&W 800's - $24,000.00 (retail) Rotel rb 1080 (used) $600.00 just doesn't make sense and you will not get the sound the 800's can produce as you indicated. Please do yourself a favor and shop for a new amp and pre, and you will say " I can't believe I thought the Rotel sounded good????? My suggestion is McIntosh 400 watts and up. Your speakers can handle up to 1,000 watts! I've heard the 800's with Krell and it sounded amazing. Good clean power and you will be one happy man! Let us know what you decide on.
thanks for inputs. Am coming around to the imperative of more power, meaning minimum 400w per side, preferably monoblocks. But I'm not yet sold on the merits of say a 6000$ amp of 400w versus a 2500$ amp of same. I think the big influence on sound quality is the power of the amp...once you get to a certain point on watts its going to be really tough to tell the difference otherwise. As to Mcintosh..have always liked their looks, reliability, value, and raw power, but they seem to color the sound, esp in the mid range. Anyway..thanks for the views guys..
Toddmore, I also feel that your speakers need and 'deserve' MUCH-higher-quality amps. I have a pair of Vandersteen 5As, also rather power hungry, and I would have never believed the overall improvements in SQ by going with a higher-quality, much-higher-power amp. In my case I bought McCormack DNA-750 monoamps rated at 650 into 8 and 900 into 4.
My experiences with these amps are detailed here...
...is a review of the predecessor DNA-500 stereo amp.
These are available (new) for $4995/pr. delivered in the US. Buy a pair; you won't be sorry. I'm so pleased with mine, I just bought a McC DNA-HT5, a 125Watts-times-5-channel amp to replace a bunch of Marantz MA500s driving center and surround channels.
yes, the Mccormack amps are really interesting. Read some very positive things about them.....tight like solid state but also an unusually nice mid range and treble. Does not appear to be any places around the Wash DC metro area to hear them but I'm going to call spearit audio and see what they suggest. For sure they would have the muscle to slap those B&W 800D silly.
Toddmorr, FWIW, I do not hear the slight softening of treble energy that Moncrieff wrote about, but probably he has better hearing than I.
The sound thru the '750s has a natural, musical bloom that I've never heard before except from Monarchy SE160s. Conrad-johnson design, which makes the McC products, is in Merilee (sp?), Virgina; maybe they can help. Start with Ed Deitemieir; he's a really good guy.