Going monoblock?

When channels share a power supply you are robbing Peter to pay Paul.

That's not always true my amps power supply is bigger than most monoblocks combined.

It is always true. There is no such thing as a power supply that will not suffer from this. Some are just better at dealing with it than others.

The only way to prevent this in a stereo amplifier is by adopting a "dual mono" design - two monoblocks in one chassis

It is always true. There is no such thing as a power supply that will not suffer from this. Some are just better at dealing with it than others.


So you think that monoblock amps with a 750 VA  transformer and 80,000 uf of capacitance in each amp will perform better than a stereo amp with a 5,000 VA transformer and 260,000 uf of capacitance.

I’m going from Mono to Stereo, from 40 w monos to 8 w Stereo... downgrade?

So you think that monoblock amps with a 750 VA transformer and 80,000 uf of capacitance in each amp will perform better than a stereo amp with a 5,000 VA transformer and 260,000 uf of capacitance.

That's hard to say. If it's actually a single set of secondary windings and cap bank that is shared by both channels, there still may be more cross talk from the shared power supply even though it is a much more robust supply. There will probably be aspects of the performance (such as deep bass) that are better with the larger supply, but other aspects (such as image width and depth) that might be better with the monoblocks. 

But it's probably likely, with a top end stereo amp with an overdesigned power supply, that the two channels actually have separate secondary windings and capacitor banks, in which case it will deliver very close to the performance of a true dual-mono design (e.g. completely separate power supplies). 

rapet
I have a McIntosh MC252 that can be bridged to mono at 500 Watts. What am I going to gain in term of sound going from a single MC252 stereo to two MC252 mono?

Many more watts, but that’s it!
Everything else measurement wise takes a hit that made the stereo MC252 what it is.

So basically (very harshly because I’m so anti it) if you want to turn them into PA amps "bridge them into mono" (that will also be unstable into low impedance SF Ellipsa is 4 ohm nominal, 2.5 ohms minimum ) .

If you have two identical amps and bi-ampable speakers, for audio you’d be better off vertically bi-amp’ing using one channel for the lows and one for the highs.
https://ibb.co/y4kzMCZ

Cheers George