Sunfire TGA 7400 versus Krell FPB 600

I am using a Sunfire TGA 7400 in a stereo system to drive Infinity RS 9 Kappa's (using 2 channels per speaker a bi-amp configuration).

I have often wondered how my multichannel Sunfire in this configuration would compare with a high-end stereo amp and it so happens that there is a Krell FPB 600 currently available for a price that I would be able to sell the Sunfire for, so I should be able to "swop" at no cost.

The Krell retailed for $12500 versus the Sunfire's $5500, so it's in a different league, but the Sunfire is only 18 months & still covered by guarantee, where the Krell is 14 years old and only has a 6 month guarantee.

A direct comparison is unfortunately not possible.

Any advise / suggestions?

Well, if it's the one on Audiogon right now, either you've already committed to it or you've lost it.

If you lost out on it, for around the same amount of money you can get a Spectron Musician III Mk2. It's a very powerful and fast amp.

Nope, it is not the one on Audiogon. I am not based in the US.

What are your thoughts on the TGA 7400 (used as explained above) versus the FPB 600? Putting it differently, if the Sunfire was yours, what would you have done?
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I have Infinity Kappa 9 speakers and have driven them in a biamp configuration with two Sunfire Signature stereo amps. The Sunfire Signature amps are much more powerful per channel at 4 ohms than the TGA 7400. The Kappa 9 will dip below 1 ohm and will make some amps call for their mama. They need lots of power. The Sunfire Signatures did a very good job, but I tried four Carver Silver 9t monoblocs and they were clearly better on the Kappas than the Sunfire Signatures. With that said, you haven't even come close to the Kappa 9 capabilities with your current sunfire. The Sunfire Signatures are rated at 1200 wpc at 4 ohms and the Carver Silver 9t are rated at 900 wpc at 4 ohms. The Carver 9t were clearly superior, but, you need four of them to make the Kappas sing.

I would suggest you try the Krell. It will hold its value and you won't lose any money if you decide to sell it. The Sunfire will depreciate precipitously....get rid of it now while it is still fairly new and you can still get a good price for it. It is a decent amp, but it had nowhere near the testicular fortitude needed to properly drive the Kappa 9's. Once you get some serious amplification for the Kappa 9's, you'll find out that you've just gotten a helluva set of new speakers. I own four pair of Kappa 9.
Ericjcabrera & Mitch4t - Thank you for your insightful responses and advise. I have decided to pursue the Krell - hopefully I'll be able to sell the Sunfire in time at the right price.