Krell or Classe better with the "new" B&W 802D ?

[misterdoggy]

Heres the question. So many of you have opinons on this and I've heard people talk of the warm feeling of Classe, but also the FPB Krell's. How do the FPB 300 350 400 watts compare with the Classe CA CAM 300 350 400 watts in YOUR OPINIONS ?

With a pair of 802D's on the way (they've been coming forever) I am hoping that my Krell Kav 2250 (250 watts per channel) won't be underpowering them. Any thoughts ? Anyone have this combo. ?

Whoops I missed the thread already in discussion thon this topic.!!! :E

[sascha h-k]

... and don't forget MarkLevinson ...


soon with 800D & DD18


sascha

[misterdoggy]

Yeah I saw a ML333 at an interesting price, but read lots of stuff that seems to favor Classe (warm easy listening) and Krell (detail and bass)

[xk8boy]

I have the 802D driven by classe 5200. And they can go loud. I think 200W is more that enought for a small to medium size room.

[misterdoggy]

The 5200 is a little less power than I have at the moment witht he Kav 2250. I'll wait and see.

[Aussie Geoff]

Hi,

I did a comparison this week at my dealers between the 803D and 802D. They were driven by McIntosh 602 amp (600W a channel). Now the relevant thing is the McIntosh had the "trademark" VU meters on the front showing instant peak power. Very interesting. I have seen the same amp drive the old 802...

Bottom line this was the best demonstration ever as to why "too much power is never enough" and why B&W recommends high current amps that double their power as the impedance halves. On Vocals listening at 4m it was a lazy 6-8W. Plunk in some bass driven music (a different track on the same Norah Jones album) and there were lots of 300W peaks. Switch to a Chinese Drums demo CD and 600W peaks and comfortable listening levels each time those drums let loose...

Scary stuff and this was at levels you could talk over...

Same speakers on a lesser amp (nameless) and the volume was the same but the bass and mid bass became congested and during the louder bass peaks the other music hardens and collapses. It seems like those instant peaks of bass and mid bass can just suck the life out of lesser amps...

On the good news front a friend has the 802Ds with a Bel Canto Evo Digital amp - 150W into 8 ohm and 300W into 4 ohm and they sing... So watts aint watts....

Geoff

[misterdoggy]

Hi,

Bottom line this was the best demonstration ever as to why "too much power is never enough" and why B&W recommends high current amps that double their power as the impedance halves.

Same speakers on a lesser amp (nameless) and the volume was the same but the bass and mid bass became congested and during the louder bass peaks the other music hardens and collapses. It seems like those instant peaks of bass and mid bass can just suck the life out of lesser amps...

On the good news front a friend has the 802Ds with a Bel Canto Evo Digital amp - 150W into 8 ohm and 300W into 4 ohm and they sing... So watts aint watts....

Geoff

Geoff

I agree... :agree:

Well, I ride my road bike here in the French Alpes and its always better on those 5 hour rides to have lots of extra "Power Bars" than not enough. :beer2: This is the normal thinking. More Power equals better sound. This as we know is not always the case. Better made quality 'less' power, is better sound, then lower made quality, 'more' power.

Having said that, 'Better' made quality and 'more' power is the best combo. I'd take a Krell, Mark Levinson, Classe at 300 watts per channel and up if I had a choice. No puzzle here, you get what you pay for. :T

[Andrew M Ward]

some 200 watt amps

Keep in mind...

Some two hundred watt amps can hit 600 watt peaks easily even though they might be rated by the Mfg. at 200.

some 600 watt amps might not be rated to 600 watts by some Mfg.

it's interesting how differing mfg's arrive at wattage numbers.

[misterdoggy]

Are you familiar with what the Krell 2250 can do. Its rated 250 per channel, but I've read their Amps are very modestly rated. IE; showcase rated at 125w was actually putting out 180w.

[krellfan]

I have the Krell 3 FPB 250M and 3 FPB 350 MCX monoblocks and the Krell amps tend to be under rated at 8 Ohms. The 250M puts out about 375W into 8 Ohms but rated for 250W. The 250M will pump out 1000W into 2 Ohms.

[misterdoggy]

Krellfan

Wow !! that's a lot more power than rated. How did you come to those figures ?

Another question. Do you let those things run all the time with TV DVD and Stereo or just crank them up for Dvd and Stereo

[jlee]

I have the Krell 3 FPB 250M and 3 FPB 350 MCX monoblocks and the Krell amps tend to be under rated at 8 Ohms. The 250M puts out about 375W into 8 Ohms but rated for 250W. The 250M will pump out 1000W into 2 Ohms.

The probable reason they underquote is because if the amp is "spec'd" like an amp that doubles in power as the load halves, the amp is a 250W amp into 8 Ohms... 500 into 4, 1000 into 2... this is a more realistic and conservative way to rate it. With B&W into the 3 Ohm range, I look at the 4 Ohm and 2 Ohm ratings more than the 8 Ohm...

[Aussie Geoff]

Hi,

Also an amp that doubles its power from 8 to 4 ohms and (as far aspossible) again from 4 to 2 ohms is what is recommended by B&W for their speakers, especially the Nautilus and 800 series. They are usually best able to follow the speakers as the impedence varies from 3 ohms to 32 ot 48 ohms as frequency changes.. In general these amps are referred to as having "massive current reserves" and sound noticably better on harder to drive speakers.

Regards

Geoff

[krellfan]

mr.doggy,

The 250M output power is based on a Sterephile review and measurement from a few years ago. I listen to 75% 2 channel music and 25% HT at moderate level. I have Revel Studios which are about 86 dB/W so they do need some power sound their best.

[james_dmi]

So, so far recommendations for 802D are:
MarkLevinson
Krell
Classe

How do these compare to the Bryston 4B-SST? Is this in the same league?

I’m going to be doing lots of listening but it’s difficult to find dealers that have these and 802D’s so any short listing help would be great.

I also need to find alternatives to the 802D at £8000 a pair I need to make sure these are indeed the best (for my ear) I can get. Any help is much appreciated.

[RebelMan]

I find the Bryston 4B-SST to be a very competent and musical amp. While I wouldn't put it in the same class as say the three you mentioned it makes for a very close runner up.

I believe the best of the best power amps MUST deliver double the power output for each halving of impedence, like the ones you named. That being said, price/performance wise the Bryston is tops even though it falls short of this criteria. An article in Stereophile some years back temporarily used a Bryston 4B-ST to drive the 800 Signature pair as part of a reference system.

However, if it were me and I could afford the ones you mentioned, then that would be the direction I would go. On the otherhand, If you are a little price senstive the Bryston will tie you over for a while.

[Andorian]

Hi,

See my other posts..,
Any one has experience with the Classe CA2200/500 on the 802D?
I am not happy anymore with the 803D, after hearing the comparison (My ears are getting so much more sensitive somehow).
will they need more power (i know they want more, that for sure) but a shift would be not flatten the output of the 802D ?
please share your experience.
greetings, Andor.

[james_dmi]

I find the Bryston 4B-SST to be a very competent and musical amp. While I wouldn't put it in the same class as say the three you mentioned it makes for a very close runner up.

I believe the best of the best power amps MUST deliver double the power output for each halving of impedence, like the ones you named. That being said, price/performance wise the Bryston is tops even though it falls short of this criteria. An article in Stereophile some years back temporarily used a Bryston 4B-ST to drive the 800 Signature pair as part of a reference system.

However, if it were me and I could afford the ones you mentioned, then that would be the direction I would go. On the otherhand, If you are a little price senstive the Bryston will tie you over for a while.

Thanks for the reply. I’m going to do some research into models from each of these manufactures.

With the idea of power doubling when you half the ohms I agree this is a good indication of current reserves but looking at the specifications of both the Bryston and Krell I have a question:

Power (W) = Current (I) * Voltage (V)

And

Voltage (V) = Current (I) * Resistance (Ohms)

From the second equation you can see that to give the same volume (i.e. voltage) you need to double the Current when you half the Resistance. Then looking at the first equation if you double current for the same voltage you need to have double the power.

So, so far theory is with the recommendation but if you look at the specifications of the Krell and Bryston you have

Bryston:

300W into 8 Ohms
500W into 4 Ohms

Krell:

250W into 8 Ohms
500W into 4 Ohms

Now the important thing would seem to be the amps ability to maintain its voltage by having enough current a low impedances. So in this case if we go purely by the rated outputs then both the Krell and the Bryston are equal to this task. Of course this is only one factor and it does not take into account what happens below 4 Ohms (I think the 802D goes down to 3.5) I does point out that the most important figure (when thinking about B&W and other difficult to drive speakers) is the 4 Ohm figure followed by the ratio between to two to try and extrapolate the power at sub 4 Ohm levels.

If we assume a constant increase in power with decrease in resistance (a big assumption!) then at 3.5 ohms we get:

Bryston:
300W into 8 Ohms
500W into 4 Ohms
525W into 3.5 Ohms

Krell:
250W into 8 Ohms
500 W into 4 Ohms
531W into 3.5 Ohms

I guess I have gone full circle here and Im agreeing with you but the Bryston does indeed come a very close second in this metric.

[xk8boy]

Andorian, I dont have the 2200 but I can say that the 5200 - which is identical to the 2200 with 5 instead of 2 channels, can drives the 802D fine. At no time do i feel the amp is struggling or loss control. Would I like more power, go some mono blocks, oh yeah. But do i need it, possibly not.

[james_dmi]

Another point to consider: Now I have looked into the pricing a bit further it seams that I could Bi-Amp with a pair of Bryston 4B-SST’s for the same price as one Krell. I wonder how a the Bi-Bryston would compare sonically to the aforementioned amps? This path also has the benefit of allowing a two part investment in power amplification. Anyone heard this??

I’m in a bit of a dilemma as to which part of the system to tackle first. Speakers sound their best when partnered with the “Right” amp (taking personal preferences into account) so from this stand point it would seem the best route would be to get the speakers first and then try lots of different amps at home till I find the right one.

But when choosing speakers room interaction is a big consideration, therefore I need to try these at home too. The problem is some speakers are a lot fussier about the amp that drives them then others. So if I do the speakers first I may well pass up on the “real” best choice because it didn’t partner well with my current amplifier.

I have been down this road before, I chose my current power amps when I though I was going to get a pair of 703’s. I tried lots of different configurations driving these speakers in my dealer until I got it right. Then having my amps sorted I could then bring the speakers home to try them in my considerably larger listening room. I then found I was completely under-whelmed by their ability to fill the room especially in the base department where they were not even up to my original speaker’s performance. I now know that I am going to have to spend a lot more on a system then I originally thought. On listening to superior speakers in the B&W range I have found all the other areas in which the 703’s are lacking. So in a way my original investment in power amps has been a waste of money.