[Rod_S]

I've seen it mentioned in the past that, and I'm almost certainly over simplifying things, that the 7's are basically a 4 running permanently in bridged mono mode then I guess that sort of explains why only the single set of binding posts and why they are placed where they are on the back panel i.e. just the right channel of the 4B chassis. If that's sort of the case is the 28 like bridging a pair of 7's? Wouldn't that then be like using two 4's per 28, this one really throws me how you are doing it.

If these over simplified descriptions are the case of the amp's design why are these bridged designs used to get the desired power rather than simply using a non bridged design and actually build a single amp design of the same power capability? What are the pros and cons of each approach? I assume not all high powered amps from other manufacturers are doing so via bridging.

Thanks

[Yitshak]

There was some old posts regarding this over here,it's not strait designe like so.
The output of a bridged 4b is not the same as one 7b (I wish it were like so for my future Bryston planes)
There are some technical modifications that involve but I remamber
James explain those in better details.

[95Dyna]

Hi Rod,

A 4B running in bridged mono mode would see only half of the load being presented by the speakers thereby requiring twice the current to handle the load.  The 7B is designed as a true mono block from the ground up.  It is rated at 600 WPC into 8 ohms so when the speakers present 8 ohms to it the 7B is capable of providing the full 600 Watts of its rated power.  The 7B's each have a higher capacitance power supply than the one in the 4B.  I am not an engineer so this too is an over simplification.

Quite often the 14B is characterized as two 7B's in one chassis which also is not correct.  Each 7B has a higher capacitance power supply than the 14B's total.

Bill

[Yitshak]

http://www.audiocircle.com/index.php?topic=18743.0

Found this one.
From this it's look like 4b's may better "milked"
with vertical bi amp then in bridge mode,if there is practical reason for doing so

Itshak