Krell FPB 600 or 400cx?

Martin Colloms tested both of them; the 400cx got 75 on his scale, the FPB 600 got 45. See the HIFICRITIC site for more.

The 600c is better. As a matter of fact the 600 beat my 350c monos and I got rid of the monos and purchased a 600. I now have a 700cx.

Do not buy a FPB 600, my FPB 600 is now a flower planter! I took off the top of the amp, removed the insides and put a plastic tub filled with dirt. it now hold beautiful flowers next to my fireplace. It now works better than it ever has. That was the most expensive amp I have ever owned that I barely used. It went back to Krell so many times I lost count. Junk! I had to build a wood crate beacuase the cardboard boxes would ware out and Krell would charge you for new box about every three round trips. If your Revels are a tough load in regards to impedance then FPB 600 is not your amp. It is two bridged FPB 300 in one chassis. Bridge amps only see half the impedance and are not stable much below 4ohms because they only half of the imdpedance. This amp could not run my old Apogee Duetta Signatures for very long before cooking it self off. Before I bought it Krell swore up and down it would drive my speakers with out any problems. I had no idea that it was a bridge amp until a friend who is great audio tech looked inside and told me. I asked the engineers at Krell and they finally admitted that the FPB 600 was two bridged FPB 300.

That's about the silliest thing I've heard Sound. I bought the big Krell when I was a speaker designer and it drove everything I threw at it. And it sounded great doing it and still does.

What was silly is the fact that Krell would build such a big amp with lofty claims that was as powerful as they said it was in terms of watts but could not drive speakers with tough loads any thing below 4 ohms and had a steep impedance curve like most planar speakers. What made the wounds of expensive repairs worse is when they said that they would upgrade it to the 600c for way too much money, and when you asked what were the changes they told me the only thing that is used from the old amp is the chassis and the power transformer thus admitting that there may have been some design flaw(s). What hurts is I bought the FPB 600 through the audio store where I used to work and paid for lots of repairs having to keep a straight face when customers asked about Krell's customer service. Even in warranty it was $600.00 for shipping and the only shipping company they would use was Ocean Air. I once thought I would save $150.00 and ship the amp Fed Ex freight they would not accept the amp although it had the proper RA. So if are ever in the Albuquerqe area just email me, you can come over and enjoy cool beer listen to some great vinyl all while looking at some great flowers in my FPB 600 planter. To Krells credit they have recently made some good changes and I think they are fixing customer service.