Classe CAM Mono Blocks or Music Fidelity 550K Superchargers?

[beden1]

I have been looking into upgrading the amps for my main 803Ds. These speakers do require some decent power.

I am currently using a Classe CAV-150 (6 channels X 150 watts), that I had set-up for bi-amping my front three speakers. Recently, I changed to connecting my five speakers through each channel. I found the sound was actually a bit smoother and open, yet less dynamic (maybe using the balanced connections helped the 803Ds).

I have been looking at getting either a pair of Classe CAM 400 mono blocks, or a McIntosh MC-402 stereo amp, or a pair of McIntosh MC-501 mono blocks. I have been looking for used if possible. The only thing I started thinking about however, is that these amps weigh a ton and also eat up a lot of electricity. They also need space to fuction properly (I'm somewhat already cramped).

I also recently started looking into the Music Fidelity 550K and 750K Superchargers. The concept looks very interesting . . . an informative discussion - http://www.htguide.com/forum/showthr...0+Supercharger

The 550K lists for about $5,000 a pair, and can be had for about $4,500 new. The 750K is new and the dealer is checking on the pricing, but we figure about $7,000 a pair, or about $6,300.

I really like the quality of sound that my Classe CAV-150 produces, but I also know that my 803Ds are underpowered. I listened to the MF 550K this weekend on both a middle-of-the-road Yamaha receiver, and on a pair of top-of-the-line Krell mono blocks (these were monsters) and a Krell pre-amp. Both were hooked up to pair of $50,000 Focal speakers that I loved, but, that's some serious coin.

The total sound stage was dramatically improved with the Yamaha receiver. The difference was stunning and was actually very good. The sound was also noticeably better on the Krells, however, the difference was more subtle. I would have liked to have heard the MF 750K on the Krells, which would have been more of a benefit over their already high output. But, even so, we could hear the difference in a more open sound stage.

Has anyone else had experience with these MF Superchargers, and am I nuts for thinking I may opt to go in their direction. At the very least, I won't end up with a hernia from lifting and moving monster amps!

Your thoughts are welcomed.

[cug]

I don't see the point in getting the super chargers instead of just one powerful amp (or a pair of mono blocks). Maybe I miss something, but you introduce another "point of failure" (for the sound) in the chain that is not necessary if you have a powerful enough amplifier.

[beden1]

A couple of other interesting links regarding the Music Fidelity 550K Supercharger:

http://www.stereophile.com/solidpoweramps/907mf/index.html

http://www.musicalfidelity.com/products/supercharger/diagnostics.html

Musical Fidelity offers a "System Diagnostic" calculator on their website, where you match your speaker's voltage 1m sensitivity in dB with your amplifier's maximum power rating to get the maximum sound pressure level in your room. (It appears to subtract around 7dB to allow for the fact that you sit further away from your speakers than 1m.) It then rates that spl as "Average Quality" of dynamic realism for 102–105dB, while one capable of only 97–101dB is of "Low Quality." Higher than 106dB and your system is rated as "High Quality."—John Atkinson

[beden1]

I guess there are a few points to consider: The weight of the large amps; the solid and stable platform required for the amps, along with proper cooling and space required surrounding the amps; the electrical energy expended to drive the large amps (much of which dissipates in the form of heat and wasted energy); the cost of high powered amps like the CA-M400 @ $5,500.00/$11,000 pair; etc.

Just a few that I was considering.

[cug]

I guess there are a few points to consider: The weight of the large amps; the solid and stable platform required for the amps, along with proper cooling and space required surrounding the amps; the electrical energy expended to drive the large amps (much of which dissipates in the form of heat and wasted energy); the cost of high powered amps like the CA-M400 $5,500.00/$11,000 pair; etc.

If you care about that, you should go back to the dealer and add some ICEPower amps to the comparison:

- Rotel RB-1092
- Seymour AV ICE Block [1]

or others. And really: I don't think you need 500W for driving a pair of 803D. An amplifier that can deliver enough current into 2 Ohms (I'm not talking into being able to double each time you get half the impedance, but it might help) and brings clean 200W into 8 Ohm will probably not sound any different, maybe even better because you are not adding another component to the mix.

So, if you want to look into high quality amplification, a Classé CA-2200 or a McIntosh MC-252 - these should give you plenty of clean power without adding another electronics component to the chain. Remember that stepping up from 250W to 500W just adds another 3dB headroom. Not more. That's actually nothing. And with speakers as efficient as the 803D you will probably NEVER need that headroom because each of these amps will drive your speakers to earsplitting levels without any distortion. And instead of the larger super charger, you can probably get a MC-402 a better price.

Really: My main concern would be adding another component to the chain which can only amplify existing distortions into higher ones instead of getting a complete clean chain from the pre to the speakers.

But that might just be me - I always try to keep the number of components in the signal path as small as possible.

[1] http://seymourav.com/amps.asp

[cug]

It then rates that spl as "Average Quality" of dynamic realism for 102–105dB, while one capable of only 97–101dB is of "Low Quality." Higher than 106dB and your system is rated as "High Quality."—John Atkinson

Wow. As much as I like my A5 integrated and the A5 CD player, this classification is just plain ridiculous. Volume has nothing to do with quality. Do you really want concert levels in your living room? I don't as this is just plain stupid if you want to enjoy listening to music for a bit longer than another year ...

[beden1]

Wow. As much as I like my A5 integrated and the A5 CD player, this classification is just plain ridiculous. Volume has nothing to do with quality. Do you really want concert levels in your living room? I don't as this is just plain stupid if you want to enjoy listening to music for a bit longer than another year ...

I appreciate your in-put as this is what I need in order to make a final determination.

My current Classe CAV-150 doubles from 150 watts at 8 ohms to 300 watts at 4 ohms per channel, and is a very fine amp. The quality of this amp is on par with most other Classe amps. It would be a step up from the ice amps or Rotel level products.

High powered/current amps, and the dB examples used in the Stereophile article, are not intended for how loud you can play them, but for how dynamic they reproduce sound at all volume levels.

The 803Ds are inefficient speakers (like many of the B&W lines of speakers), and demand higher currents to produce their excellent dynamic range capabilities.

[cug]

My current Classe CAV-150 doubles from 150 watts at 8 ohms to 300 watts at 4 ohms per channel, and is a very fine amp. The quality of this amp is on par with most other Classe amps. It would be a step up from the ice amps or Rotel level products.

Whatever.

Nevertheless, you might get about 6dB more out of your speakers in continous output. Peak output with short dynamic peaks is something different.

High powered/current amps, and the db examples used in the Stereophile article, are not intended for how loud you can play them, but for how dynamic they reproduce sound at all volume levels.

Which is a joke in itself. An amplifier needs to provide enough current - that's all it is. There is nothing like "faster" or whatever all the magic words are. Dynamic is directly related to power output and therefore to "volume levels".

The 803Ds are inefficient speakers (like many of the B&W lines of speakers), and demand higher currents to produce their excellent dynamic range capabilities.

This is not true. The 803D is with 90dB an efficient speaker for a normal HiFi system. Is has some ugly impedance behaviour, so you want a really stable amp that stays stable down to 2 Ohm to be safe, but that's about it. And ALL the mentioned amplifiers provide that. Get the one where you like the frequency response the most and be done with it. Don't let magazine or obscure reviews get in the way. Trust only your ears and your ears only if you do exactly volume level matched double blind testing.

Just take this numbers (at listening position, 10 feet from the speakers, speakers not in a corner, two speakers) [1]:

- 106.3dB for a 200W amplifier
- 109.3dB for a 400W amplifier
- 110.3dB for a 500W amplifier

Do you really want to tell me, you hear the difference between 109db and 110db without doing A/B switching? And here we are talking about continous SPL not dynamics.

And: 110dB is a jet flying over your head about 900 feet high. Which is pretty damn loud!

[1] http://myhometheater.homestead.com/splcalculator.html

[wettou]

No question Classé CAM400 any day Also I agree last thing you want is more stuff between the speaker and the amps!

[NonSense]

I'll just throw this out there.

I am a true skeptic of the configuration proposed by the MF Supercharger amps. I have a MF amp which I like alot, but I often find their marketing material laughable.

The interesting thing, which I though was worth mentioning, was that twice now I have seen the superchargers at a trade show. Since I am interested in seeing one in action, I ask for a demonstration and explaination of the setup. Both times, they were configured as mono blocks via the line input and connected directly to pre-amps. This leads me to believe that their performance may be slightly better when the line input is used. Their specifications also seem to support this opinion. Which leads to me to question their marketing strategy again.

If they could hold their own as mono blocks, why not market them this way, with this speaker level input as an alternative feature. It's almost like they are trying to create a new market segment.

I would stick with upgrading to a tried and true good quality amp. IMO

[beden1]

This is why it is a good idea to listen, then think, then read about and ask questions, and then think again about buying electronics . . . instead of jumping on something that turns you on at the moment.

I originally got the idea to get a more powerful amp for my 803Ds, when I recently (about 8 months ago) purchased a used Aragon 8008 X 3 amp (300 watts X 3 channels) for another setup. This setup uses A/D/S 910s that I've had since buying new in around 1974-5. These are very efficient speakers at 93 dB at 3 meters (the 803D sensitivity is 90dB at 1 meter). In the owner's manual, it had the same graphs for determining what power is needed to run these speakers at optimum. It takes into consideration the size of the room, seating distance, etc. I used to use a two channel Aragon amp rated at 125 watts RMS to drive these speakers. The Aragon 8008 X 3's output, according to their chart for these speakers, would be at the top of their scale for peak performance. With the new amp, my A/D/S sound spectacular, and the difference made me mad at myself for not doing this sooner.

My 803Ds sound very good using my current amp, but driven through my CP-500 for 2 channel, they could stand to be more dynamic/full sounding (even in the room that is large and I would classify as being on the lively side). The 803Ds are listed at 90dB sensitivity at 1 meter. At this level, even my A/D/S graph from the 1970's showed they would need 500 watts per channel for optimum performance.

I have been thoroughly enjoying 2 channel listening, and would like to get peak performance. I also feel that the 803Ds are capable of much more than I am currently getting out of them. So, I have been considering my options for an amp upgrade. I also plan in the future to get larger B&Ws like the 801Ds or the 802Ds, and probably move the 803Ds to the rears.

The other consideration I have is space limitations with the cabinet and wall. I either bite the bullet and have something like a nice hidden equipment rack built into the wall (which I'd hate to do until I felt my system was complete), or try to get pieces that fit what I now have. Besides their massive weight, the problem also is the depth of many of the larger multi-channel amps like McIntosh and Classe, have depths of 20"+ without allowing for cables. Most cabinets are a maximum of 19". (mine is 21 inches in depth)

Right now, I think I've narrowed my options down to a pair of Classe CA-M400s or the McIntosh MC-501s (mono blocks). Both are more shallow in depth than their multi-channel amps, and having heard the monos alongside their other high powered multi-channel amps, I guess I walked away having more confidence in their abilities if nothing less, as most of them sounded excellent.

I would prefer Classe as it would go with my CP-500 and I do feel their sound matches very well with B&W speakers, but I guess it will have to come down to the value equation in the end.

[wettou]

Yes Classé was designed with B&W

[beden1]

I just purchased a pair of Classe CAM-350 mono amps. Thanks for the in-put.