[redbook]

Technically... The 4's are kind of already monos, just switch them to bridged operation.

Something I would really like to see would be a vertical option for the 7's and 28's. I think when it comes to monos the vertical approach looks better aesthetically when out by the speakers. A few manufacturers that do or have done vertically orientated monos are Theta digital, Mark Levinson and Classe.

  This is not what I mean. I was thinking of a smaller chassis sort of like a power pack but with a regular face plate ect. .

[95Dyna]

Technically... The 4's are kind of already monos, just switch them to bridged operation.

Something I would really like to see would be a vertical option for the 7's and 28's. I think when it comes to monos the vertical approach looks better aesthetically when out by the speakers. A few manufacturers that do or have done vertically orientated monos are Theta digital, Mark Levinson and Classe.

This is a common misperception that a stereo amp such as the 4B is "technically" a mono block because all you have to do is bridge the two sides into one.  A very serious flaw in that perception is that a stereo amp bridged in mono only sees half the load from the speaker.  For example when a true mono block amp is presented a 4 ohm load it must provide current necessary to drive a 4 ohm load where as the stereo amp bridged in mono must provide current to drive a 2 Ohm load.  This is why a 4B in bridged mono is not the same as a 7B, not even close.  Where the confusion comes in is in marketing specs that will rate both at 600 WPC and say nothing about current into load.

[Rod_S]

All true and as pointed out it absolutely doesn't turn it into a 7B. At the end of the day though I guess that's only a convern if well it's a concern to the individual and how well they are looking out for their speakers.

I don't think I've ever seen a recommendation to actually run a pair of 4's bridged, not even by Bryston so that makes me wonder why even include that as a feature due to the pitfalls you mentioned.

[James Tanner]

Hi Folks,

A 4B in 'MONO' will work fine as long as the nominal impedance of your speakers is 8 ohms or higher.  If your speakers are less than 4 ohms nominal then we recommend 7B's.

When the impedance drops in a speaker the amplifier has to deliver more 'current' than 'voltage'. When the impedance goes up then the amplifier has to deliver the reverse - more 'voltage' than 'current'. So depending on the speaker chosen the amplifier chosen should match the load requirements.

So if you bridge a 4B into a 4 ohm speaker load the amplifier actually 'sees' 2 ohms and under those conditions may 'Current' limit on transients whereas the 7B would just coast along.

james

PS - also remember a 4B (as with all our amplifiers) is actually two mono amps on one chassis - the only common part throughout the amplifier is the power cord from the wall.