Matching preamp to amp

While the guidelines above are generaly true, some manufacturers such as Rowland have different philosphies about impedance and "power matching".

Gunbei, I'm not a Rowland owner and I'm basing this on a recollection of an old review, so please take this accordingly. I believe that Rowland believes(d) in matching output to input impedance as a form of power transfer. Maybe some Krell fans can report if this is the same thing that Krell does with their CAST system.

I posted this some time ago, but, I can't find it in the archives. It was originaly pubished in "the absolute sound" and written by David A. Wilson. I am of the understanding that "TAS" suffered a fire some time ago and this article is no longer available. With that in mind I don't think "TAS" will object to me posting it:" Guidelines For the Consumer...
IMPEDANCE.....PREAMP OUTPUT...........POWER AMP INPUT........
"HIGH"1.......OVER 600 OHMS...........OVER 100 K OHMS.......
"MEDIUM"1.....200-600OHMS.............20 K OHMS TO 100 K OHMS
"LOW"1........LESS THAN 200 OHMS......LESS THAN 20 K OHMS....
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1In DAW's opinion, no official standards exist."

I know Art has has his reasons but 600 Ohms is still quite a bit.