which is better? Stereo Amp or Monoblocks?

+1 for stringreen.

The thing is you have to qualify any answers with 'all other things being equal'.

If you do that then monoblocks are the clear winner. One advantage is you can place them by the speakers and keep your speaker cables short. This can really help with definition and impact, particularly if you have 4 ohm speakers. But my speakers are 16 ohms and I find that short speaker cables help them out too.

Atmasphere,
What are the advantages of a loudspeaker system with a 16 ohm nominal rating???

I prefer separate monoblocks but each has its sonic merits.  After building both push-pull and SE amps, some of which have been very similar in design and build except one being monoblocks and the other a single-chassis stereo amp, I reached a tentative conclusion--- the main differences I could hear were actually in imaging and soundstage characteristics.  The stereo amp seems to have greater image density in the middle of the soundstage and less extension to the extreme sides.  The monoblocks have a bigger soundstage with greater extension on each side but images are not as precisely fixed in space in the middle.  Overall I prefer the monoblock presentation but I can see how someone else might prefer the stereo.  I say "tentative" because it is really difficult to be sure what you are hearing is due to the monoblock vs. stereo chassis and not some other issue, but that's what I have heard on a couple occasions when I was able to make such a comparison.

@ mr_m

What are the advantages of a loudspeaker system with a 16 ohm nominal rating???

All amps have less distortion driving 16 ohms as opposed to 8 or 4. Tube amps in particular will not only have less distortion, but (if transformer-coupled) will play with wider bandwidth and slightly more power because the output transformer is more efficient. 

With our amps (which have no output transformer), there is less heat and power draw from the wall; the smaller amps we make (M-60 and S-30) also make more power.

Finally, the speaker cables have far less impact on the sound and you can run them longer lengths.

I don’t think amp makers will make amps which have everything their mono blocks have in their 2 ch amps. Not even in their dual mono single box setups. In fact there are a lot of ‘mono’ amps which are merely ‘bridged’ stereo amps, even if dual mono on one chassis. It’s a cost effective idea.

As such, within that brand, there would be no reason for buying their monos… apart from a slim chance the monos had greater power output, but then they would not be the same as their 2 ch counterparts yet again.

Its all about $$$$. Topology isn’t always the big deal with some amps, say tube amps for example. There are tube monos running sE only. Very nice ones.

There is a very good argument which paralelles this thread…. Fully differentially balanced or single ended designs, which is best?

Cost no object (C.N.O.) builds of either SE or XLR amps should have the balanced amps doubling the costs of the SE amps provided both amps were made . of identical parts as the XLR amps use effectively a twin SE arrangement or twice the parts list essentially..

Power supplys are where most all upgrades, mods, performance enhancements begin despite the device, but especially with amplifiers. Stereo amps run nearly the gamut dual mono 2 ch amps run but their power sups as previously said already get upgraded… pretty often in a dual stereo amp.

If kept within the brand, Monos, worth their salt in design, build and topology are generally going to on paper at least out perform the other two amp entries.

However, there are some stereo amps sitting on one chassis which cost way more than some other brand’s mono blocks. Way more!! Way better sounding too.

It all comes down to $$$. That and preffs. If on the short list, I’ll opt for monos every time, provided…. Performance is better, the added costs are part and parcel their requirements for gaining that added edge. Albeit, wires, platforms, power cords, etc..

Size and space are considerations too. I’ve owned dual mono amps that are quite the monsters to move about the house, or even just a few feet from there to here and mono blocks that were far lighter and easier to rearrange physically.

All that said, recent Integrated amps from some very upscale amp makers seem to be making a great argument for themselves in terms of ‘voice’, synergy, and simplicity.

Mono block amps indeed do not have to be in the mix for a system to sound great and perform exceptionally well.