Up grading power amp... Mono blocks or stereo amp?


I am thinking of upgrading my Rogue Audio ST-90 power amp.
My System: Rogue Audio Persious Pre amp, the st-90 powere amp, Krell SACD Standard CD player, Pro-ject 10 Turntable w/ Shelter MK II cartridge, Straight wire Interconects and Speaker cables, And B&W 803s speakers. This amp is nice but I think I could get an amp that is more quite, richer, and a bit more powerful. I was thinking about the Rogue Mono Blocks. What are the advantages/disadvantages of Mono Blocks versus a stereo amp? And yes, I want to stay w/ tubes.
dougdubin
>> There are many excellent stereo amps and an equal number of poor mono blocks << (Audiofeil)

Obviously I was meaning "at the same quality level"
Everyone knows there are poor monos and good stereo amps!
But when you have the same quality level .. imho .. two monos are "always" better than the equal stereo amp
I think that a stereo amp can sound every bit as good as a monoblock amp of similar "quality" - that most of the "advantage" is theoretical with a little bit of "marketing" thrown in. But monos do help at keeping speaker cables very short, which is not a bad thing.
The primary argument for monoblocks other than shorter speaker cables (which by itself is a pretty important thing) is that there are no shared power supplies. An amplifier that has separate internal power supplies will be described as 'dual mono', but most stereo power amps do have shared supplies. In most stereo amplifiers, the incentive is price, as the chassis is often the most expensive part, followed by the power transformers.

Conversely, monoblocks are usually built to a higher standard as cost plays less of a role.

Overall these are generalizations, but good to keep in mind when looking at a specific product. They often are helpful in guiding one to an audition, but the audition is really the bottom line.

Atmasphere...Another important advantage of monoblocks, at least for high power units, is that they are not too heavy to pick up! That, and the short speaker wires is why I have monoblocks.

I think that the shared power supply thing is a bum rap, at least for the amps I have owned. It is usually only the transformer which is shared...each channel gets its own capacitors which will continue to run the amp for several seconds after its ac power is removed. One trick to help amps with so-so power supplies is to run one channel inverted, so as to even out the draw on plus and minus rail voltages. Some amps (the old dynaco ST120 is one) are spec'd for power with one channel inverted.