450 Pound Monobloc Amplifier

Mitch4t, the 54Lbs per chassis amps from Rowland (M625 and M725) are running in class A/B rather than class D.

Mapman, there is starting to exist rumbllings that recent amp implementations based on new modules may constitute entirely different kettles of sonic fishes. Definitely, some formal comparative reviews of some such creatures would be welcome.

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Highly efficient, compact, light weight, 1500 watt DC switch-mode power supply provides optimum voltage regulation for all circuits and operating conditions, and allows for quiet operation over a wide range of AC mains power sources.

Guido...above is the quote from the Jeff Rowland site regarding the 725 monoblocs. Is the power supply switching technology mentioned there similar to the class D switching amps? I've heard class D amps referred to as 'switching' amps. Is this Rowland a 'switching' amp? No big power supplies in the Rowland to be seen.

Looking at the naked chassis before the innards are put in the amp, it looks like at least 60% or more of the weight is solid aluminum billet chassis.

Click Here To See The Aluminum Chassis...(scroll down when you get to the page)
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Hi Mitch4T, all current Rowland amps and pres are based on switch mode power supplies (SMPSs). However this does not mean that the amps are necessarily running in class D. For example, look at the specs for M625 stereo and M725 monos...

http://jeffrowlandgroup.com/kb/categories.php?categoryid=203

and

http://jeffrowlandgroup.com/kb/categories.php?categoryid=208

G.

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Guido....class D or not...the switching power supply is what makes the amps able to be much smaller. That is the real point here...the ability to get good power in a smaller package.

I see that the Rowland has substantial sized heat sinks relative to the overall chassis size. Why would an amp with a switching power supply need heat sinks like that? I thought one of the main advantages of switching power supplies was a great reduction of amplifier heat.
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People believe that the main reason for switching power supplies is efficiency and size while they produce noise (tradeoff). In reality switching power supplies executed properly allow to reduce noise. For that reason Rowlands Capri preamp is powered by switching power supply (where efficiency is not important)

Yes, switching power supply is the same as class D. In fact class D was invented when engineers who designed highly responsive switching power supply showed responsiveness by making power supply to play music.