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Krell KSA 300S or FPB 300?

Hello all on a-gon,

I'm looking to get into some Krell amplification. Right now I'm considering the 2 amps above. I would like to get some of your expert opinions as to which ya'll prefer and which you would recommend. I would also like to hear why you prefer & recommend your choices.

I'll provide some of our associated equipment without getting overly detailed...

Amplifiers: Musical Fidelity KW500 (Selling) & Legacy-Audio Monoblocs
Speakers: Infinity Prelude MTS' & Legacy-Audio Focus
Digital: Esoteric DV-60 & Marantz BD8002
Analog: TNT IV with mucho upgrades
Phono: X-Ono
Preamp: Legacy-Audio NexStep. Preamp replacing the NexStep: Krell Audio/Video Standard from a super fine fellow a-goner. Greg, thank you again for the AWESOME Krell!

So there's the condensed version of our equipment.

As far as musical taste... my wife and I enjoy the following. In no particular order...

Rock
Blues
Big Band
We'll... actually we like just about all genres except OPERA!!!
We also like our music as low as background and all the way up to concert levels whilst enjoying Several-Frosty-Beverages.

Oh wise one's... please grace me with your honest opinions.

I hope that gives you's guy's enough info to make a choice/recommendation.
If any other information may help you with your recommends please let me know.

Thanks,

Skip
128x128joysjane

Showing 3 responses by brf

brf
1,715 posts
 
IMHO, the Krell KSA "S" series amplifiers were one of Krell's worst efforts. I would take an older KSA150, KSA250 MDA srries etc. over any of the "s" series amplifiers. I also think that the FPB was much better that the "s" series.
brf
1,715 posts
 
The "S" series stands for Sustained Plateau Bias technology which was first introduced in the Krell Audio Standard. This is a variation on the "sliding bias" idea, except that bias is changed in discrete steps rather than continuously. A so-called "anticipator circuit" at the amplifier's input responds very quickly to an increase in signal level, so that, by the time the signal reaches that output stage, the output will be biased to class-A.

The KSA S-series amplifiers did not have have the same deep bass as the former KSA / MDA series. Some felt that this was due to the anticipator circuit and the way it was employed in the s-series amplifiers. I found the S-series amplifiers to sound sterile and less dynamic than the former KSA. I am not a huge Krell fan, but I could live with a KSA 50 or a KSA 250 amplifier. If you have the space and are not too concerned with the heat issue, I would go for a KSA 250, invest in a recap (if and when needed)and you will have one of Krell's classics. People still ooh and awe over the performance and sound of a Krell KSA 250, but rarely do you hear them speak of the KSA 200"S" in the same regard. Just my 2 cents.
brf
1,715 posts
 
The KSA 250 has balanced inputs and SE inputs. The heat generated by the amp has a tendency to potentially dry out caps, therefore, requiring replacement. With respect to heat, the amp does not need any additional cooling, it just raises the room's ambient temp.
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