AudiogoN Forums: Best Krell amp for a 15amp wall outlet.

Best Krell amp for a 15amp wall outlet.

So I moved into a new/brand new house with decent wiring but nothing too special. So I plugged my FPB750MCX amps in there hoping for the best and they actually turned on with-out blowing the breaker right away, good so far. The sound was not right though, the speakers are the little Apogee Caliper Ultimate so about 85db efficiency and about a 3-4 ohm load. This set -up was running CAST from a KCT preamp and just sounded like it was straining. If we cranked it up the breaker would blow.

Next step was to hook up the KAV 2250 and that sounded pretty good and could definitely flex it's muscle without too much trouble. But the FPB sound was not there. Just for kicks we also tried a S300i in theater mode from the balanced connection and it sounded ok (surprisingly good bypassing the preamp section)but the 2250 was much stronger and more detailed. The S300i would also shut down if driven hard into these speakers from thermal overload.

Next step was a FPB200C stereo amp plugged into the same wall socket and this really sounded good again. Much stronger, bigger soundstage but more than that the magic was there. Tons of detail, more punch a ton more bass than any of the previous set-ups. The mid-range is really good here and the amp does not sound strained at all although a 220V 30amp circuit would be better.

So all this was done through a standard wall wiring with a PS Audio Soloist Ci. I thought this would be a real world set up for a typical apartment. The FPB200C really was the ticket for the power we had available. The mono amps really do sound better and with two dedicated 220V 30amp circuits they will sound even better, which I am doing. But if you have limited options I think this was an interesting experiment. Yes the Big amps sound the best overall but not on a single 15amp 120V circuit, the FPB200C was the real winner.

Rminsf (Threads | Answers | This Thread)

05-04-12

Responses

05-05-12: Lloydelee21
Hi Rminsf,

Sorry to hear about power limitations. Query: would you rather give up your 750mcx monos...which i am told are some of the best amps Krell ever made...or pay an electrician to come in a see if he can improve or optimize your power supply?

If replacing equipment, perhaps 700cx? I know many people were 'done' with that stereo amp. fpb 650 is another obvious choice...with you trying to 'play to the limit' of your existing power supply.

May wish to contact Krell or D'Agostino at his new company. Good luck!
Lloydelee21 (Reviews | Threads | Answers | This Thread)

05-05-12: Elizabeth
Run your amps through a Fruman REF20i with a powerfactor giant cap to 'stiffen' the power. You might be suprised at the improvement.
A Torus works too, but the Torus power device would need a 220V supply. (to deliver 120v)
Elizabeth (Threads | Answers | This Thread)

05-05-12: Foster_9
If you run your Krells through the Furman, I'd bet you'll be thinning out the sound.
Foster_9 (Threads | Answers | This Thread)

05-05-12: Tmsorosk
I'll bet so to Foster-9, but the overall sound may or may not be worth the weakening of drive and power that may occur. I can't recall ever blowing a house breaker with my hi-fi.
Tmsorosk (System | Threads | Answers | This Thread)

05-07-12: Dancer
I have a Krell FPB 400CX with a KCT all off a 15amp outlet with out any Issues at all. Believe It or not my system sounds extremely good.
Dancer (Threads | Answers | This Thread)

05-08-12: Erikminer
OP said :So I moved into a new/brand new house with decent wiring but nothing too special.

Why not just get an electrician over to pull new wire at least 12ga or better yet 10ga and switch out the breaker to a 20amp

Or just have him run a new dedicated 10ga run with a 20amp breaker.. gonna be cheaper than than buying new power amps
Erikminer (Threads | Answers | This Thread)

08-17-12: Rminsf
Small update, I tried a few different things here. First with my PS Audio P-1200 to the FPB 200C, this cleaned the sound a bit more but made the supply problem worse. Then I temporarely installed my Torus WM100next to the stereo with 6 GA 240 supply and 10 GA to the dedicated outlets, WOW yep that fixed it, clean dynamic and limitless power. Now to actually install it all again in the new house. nothing like a bottomless well of power to make a Krell do it's happy dance and sing. The torus has a 100 amp supply of 240 and is rated for 100 amps of 120 output but I think that is insanely conservative, plus it's rated at over 400 amps short term so I'm thinking I should have enough now,
Rob
Rminsf (Threads | Answers | This Thread)

08-18-12: Mikey8811
What does a dedicated 15 amp wall outlet do for a FPB 200c in terms of the highs, mids and lows?
Mikey8811 (Threads | Answers | This Thread)

09-11-12: Mikey8811
Hi

Rminsf, any feedback on the effects of a dedicated wall outlet?
Mikey8811 (Threads | Answers | This Thread)