Going monoblock?


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? I have a pair of Sonus Faber Elipsa
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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

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). 
I’m going from Mono to Stereo, from 40 w monos to 8 w Stereo... downgrade?
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.
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
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.
To me the most noticeable to me was an improvement in dynamics and more pronounced transients in the material. I believe that’s due mainly to each channel having its own power supply stage. When channels share a power supply you are robbing Peter to pay Paul. 
Monoblocks give you an entire amp dedicated to one speaker, and no crosstalk, which corresponds to better separation, wider soundstage, better dynamics, and sometimes improved clarity, but there are lots of variables.

You could always ask Sonus Faber what they recommend.
Sell it and move on..but if you love the 252/famous mac house sound) dont buy the 452..I go with a 402 or 501s...
The SF Ellipsa is 4 ohm nominal, 2.5 ohms minimum and have a phase angle at 70 Hz that eats current. They really don't go that low into the bass and roll off quickly after the port tuning at 32 Hz. So the question becomes, how much power can they use because, unless mismatched to the load, the amps won't change much in character.

With the MC252, you have the mono options of either parallel or bridged for 500W. Parallel would be better for low impedance/high demand loads. Seen special, short wires for this purpose with Macs. Parallel is rather unique for a SS amp. Aside from Mac, I've only seen Bryston offer this and only as a factory option. When bridging amps, you have to be careful about the load because the current doesn't rise along with the power. With a few exceptions, bridging most amps is generally not recommended for 4 ohm loads.

Then again, what could be more macho than a pair of behemoths with big blue lights?
True monoblocks have NO crosstalk, highly valued by many. There are many nice monoblocks out there, keep an eye on the used items for sale here...

-RW-
I agree with Marakanetz.
It would be best IMHO to buy true monoblocks. Dedicated monos are designed around one input and one output. There is no forcing the amp into doing a job it is really not designed for. (even if capable) I have heard that bridging is far from an ideal circuit and has a proonounced effect on the sound. Do a search of this forum for "Bridging" to get more info.