Still working on choosing a power amp

Yes, but do you think you loose a little of that tube sound?

Bob,
The Rogue Perseus has an Output Impedance of 450 Ohms. Does that mean the input inpedance of the power amp should be 4500 ohms? So, for example the Mcintosh line of SS amps have an input impedance of 10,000 ohms... therefore would that be a poor match?
Doug

Output impedance is lower the better, and input impedance is higher the better.

07-21-08: Dougdubin
Bob,
The Rogue Perseus has an Output Impedance of 450 Ohms. Does that mean the input inpedance of the power amp should be 4500 ohms? So, for example the Mcintosh line of SS amps have an input impedance of 10,000 ohms... therefore would that be a poor match?

The 10x rule is a guideline. Your power amp should have an input impedance of *at least* 4500 ohms. If it's higher than that, that's better, as Jylee said.

07-21-08: Dougdubin
Yes, but do you think you loose a little of that tube sound?

SS amps sound different than tubes. Many people prefer tubes. Why do you want to change the ST-90s? Do you play your music loud? Are you running out of juice at high volume?

I love big sound and like my music on the loud side. I had been searching for the amp that invariably made great music. I was using 400wpc SS amps. They had that dreaded glare and would cause listener's fatigue quickly forgettaboutit.
I finally listened to my old pal Trelja who in his philosophy page (Ultrvioletaudio.com) is very firm about the fact that only tube power amps or integrated with tubed power tubes could ever give you true tube sound.
I know, as does he, that this runs contrary to popular belief and is hard to accept. The idea to many, including myself, was put tubes in the signal path and that's all you need.
So I got the requisite tube preamp only to suffer more. Finally I sold the SS monoblocks and got tube monoblocks. Losing more than 300wpc. These amps put out 75-80 wpc and I can't get the amps to clip even playing in the high 90s dB ten feet away. My speakers are not all that sensitive JM labs Focal Elelectra 936s I think they are a 91dB perW/M speaker. The sound is pure glory you have a tube power amp correct? Why are you unhappy?

Thanks, for all the responses. Yes, I like the tube sound. Yes, I play the unit a bit on the loud side... but, just a bit. I feel my system is lacking. I am currently demoing a MC402. The speakers have really opened up. At 8oms a little too bright. It was like someone turned my tweaters on for the first time. At 4ohms, not as bright. A much more true sound. From what I have read and experienced the B&W 803s's require power. Would love to demo the Rogue M-150 monoblocks. No dealer carries them here. So, that poses another problem.

In a previous system, I used the Krell KAV Series Stereo Components (SACD Standard, KAV-280p & KAV-2250 - via balanced) with a pair of B&W 803s and Straightwire Cables, and it was an excellent sounding system. I would highly recommend trying the Krell KAV-2250, the 803s sounded great when driven by this amplifier, with excellent dynamics, imaging & bass/weight + smooth highs.

suggest using the mc402 on the 4 ohm taps for the 803s - that is what I do and it sounds great - plenty of power - I am using a mcintosh ss preamp - compared to the mac tubes and the audio research tubes - the mc220 would be my choice for a tube preamp - it is kind of 'muddy' but not as much as the audio research I listened to and more than the mcintosh 2200 or 2300 - which to me just did not sound that much different than the SS. If you like the tube sound, might as well go with a preamp that really has the tube sound - to my ears the audio research was just too far in that direction. I would definitely demo the 220. Anyway I would not move off of the 402 - fabulous amp - my feel is if you want tubes in your system, go with them at the preamp - the 402 is not going to do anything other than amplify what is fed to it - if you feed it a tube sounding signal, you'll still get the tube sound - Cannot go wrong with the 803 in my estimation - the only other speakers that I found as a close second or maybe even better were the Dali Mk II 400's - those were nice - just could not make the move to a ribbon - the Genelec monitors were also nice - it just got to be too difficult to find a pair big enough without driving a couple of states away.

The sound of the c2200 and c2300 may not be much different than ss but the ease of resale is better and depreciation is less. Something to keep in mind.

Hello Dougdubin,

I have 802N and the best power amp by far is Spectron Musician III SE. You can match it with geood tube preamp as well. I know other owners of B&W 802 and 803 who have Spectron and extremely happy!

Good Luck!
Rafael