B&K Amplifier Question?

[billyjclark]

Hello All,

I am new to this site, been on others like it for awhile now, but I like the specialty club section that is featured on this forum.

I am debating between B&K and Rotel separates. I am leaning towards the B&K Reference 50 (assuming the series 2 has eliminated the popping and clicking issues....), but I have some serious concerns about the amplifiers from B&K.

For example, how can the Reference 200.5 and the 200.7 only differ in weight by 2 pounds? The same is true when you compare all the 5 channel vs. 7 channel (or mono vs 2 channel) amplifier designs offered by B&K. I am no electrical engineer, but I don't see how it is possible to increase the output of an amplifier by 40%, without drastically affecting it's weight. If not, then some crucial internal parts (capacitors, power supplies, toroidal transformers) MUST be shared!

Please keep in mind, I am not bashing the B&K design, as I've already stated I am very pleased with the demo's I have heard of their product and am seriously leaning toward the B&K over the Rotel. However, if I am going to lay down that kind of cash, I would hope someone could explain this to me (the sales reps at my local store have all looked at me like I am from another planet when I bring up the weight issue.....I can see it goin through their heads, "But, the product brochure says.....)

[Hoopofficial]

I'm no techy, but I think the majority of the weight is related to the size of the heat sink inside the unit. That is unchanged between the two. I would call B&K and ask them. They are great at answering these questions. I purchased mine from Gator at Cinemasource.com. He is a custom installer who is factory authorized and can give some good deals. Gator is great to deal with. Good luck. I have had issues with B&K but they have stood behind their units and I have a great sounding system once they got the "kinks" out.

[Glen B]

I agree with Hoopofficial. The heatsinks (and power transfomer) together should account for the majority of the weight and are probably the same between the two amps. The main difference between the two is likely just a couple of circuit boards and the output terminals for the two additional channels.

[billyjclark]

Thanks for the responses. I would agree that the heat sink does probably make up most of the weight within the chassis....I am just wondering how the actual output (with all channels driven) could be the same without upping some of the other internal parts (which I think would increase the weight by more than 2 lbs.

Good call, hoopofficial (no pun intended), I will put in an info request to B&K about this question. You are right, they responded very quickly to a question I had about the CK1.2 Keypads which are designed to be used in different zones located around the house (they have tested up to 10 "daisy-chained" with full functionality, FYI).

Also, I wonder if anyone knows of a review where they tested ACTUAL output of the 200.7, with all channels driven? That would answer any of my concerns about the power output (without the additional weight).

[Dmantis]

The amp is the same with adding 2 more channels.

B&K make wonderful amps and I don't see any concern here. When you make 5 and 7 channel amps , the current goes down. It gets shared between the channels. The 5 channel version will have slighty more current. This current may never be needed unless you have very demanding 4 ohm load and in the 80's db rated speakers. Even then the overall volume you run the system at will also determine if you need this slighty more current. You should see the sixe of the caps they use, there huge. They store plenty of reserve power for really good dymanics. the 200.5 as well as the 7 are really dynamic.

I will tell you from experience that the B&K 200.7 is a beast. It can drive just about any speakers on the market at reference volume all day long and into Tuesday. They have plenty of current.

You can look at the entire B&K line and find awesome dynamics. There receivers are rated one of the very best money can buy. The amount of power there receivers have is like having seperates. There receivers are better in my opnion then alot of seperates at ther eprice point.

What speakers are you going to use. I believe sound quality is so important.

Rotel makes wonderful amps as well. There not current shy anywhere. They can compete with B&K. I feel at this level it's about what sounds better to you. You can't go wrong with B&K or Rotel unless your asking more then what they can provide. You need to be asking the extreme to do so.

Good luck with you upgrade and let us know how you make out,


Dan

[RenoReno2]

I have the 125.7 s2, and all I can say is Wow!! actually I just got the amp a few weeks ago and I'm thoroughly enjoying it. I tried out a rotel with similar wattage and it was just as good. Rotel is more of a neutral sounding amp where the B&K is a tad bit higher. Basically I went with the B&K for the looks, I am into plain and simple, where the Rotel does look nice it's just not the look I like. I think the sound quality of the B&K would be more suited for a Home theatre where as the Rotel would be more for Music... just my opinion though. Good Luck!!

one last thing..
My only complaint about the B&K amp is that it runs Really hot. My brother in law has a Rotel amp/system and he can blast it for hours and it won't be nearly as hot as where the B&K will be after 20 minutes.

[billyjclark]

Probably should have mentioned this at the beginning.....

The amp/pre-pro will be driving

Mains - B&W DM604
Center - B&W LCR600
Surrounds - B&W DM601 (4 of these for a 7.1 system)
Sub - SVS PC+ 20/39
Player - Denon DVD-2900
Tactile - BK2 Tactile Transducer

Everything is bire-wired with Ultralink and interconnects are all Canare or Audioquest. It is currently being ran with an ancient Yamaha RXV-595 receiver (last thing to be upgraded, obviously....) 70W x 5 channels at best.

Anyway, whatever separates I end up going with, I know I will be more than happy. Thanks for the vote of confidence dmantis, that was the kind of response that I was looking for from B&K owners.

[Dmantis]

billyjclark,
with that system you own I suggest looking at the B&K avr507s2 receiver. It's plenty to drive the B&W's you own. Save yourself some time and money and go with the 507 , it's one of the very best sounding receivers on the market today. It's sounds almost exactly like the ref50 and st125.7. Very hard to tell any difference.

This would be my choice.

Dan

[Cowanrg]

i agree, i wouldnt do separates unless you really really want to. but its not going to gain you a whole lot. if you plan on eventually upgrading speakers, then maybe think about separates, but if i were you, i would do the receiver.

[billyjclark]

Sorry guys,

I don't have the cash to do major upgrading (several items at a time).....

The separates are being considered because I probably will want to upgrade speakers at some point. I know the resell value of the B&W 600 series is really good on e-bay, so I won't have to dig TOO deep to climb into the 700 series.

I will however, take a serious look at the B&K receiver, it does look like it will do everything I will ask of it (at least right now). My only concern is with the 604s....they are a fairly large tower (1-tweeter 1 kevlar mid and 2 drivers for bass), and I have heard them demo'ed (the dealer from which I purchased) with an RB-1080.....WAY BETTER than the Marantz receiver we were A/B comparing it too (the Marantz was the closest thing they had to compare to what I already had at home). Anyway, I would love to have enough amplifier power to listen to music in 2 channel with the sub off (and I just thought that if I could get 200wpc, then why not?)

[Dmantis]

Marantz makes wonderful receivers but are no match for Rotel in any form. Even the rsx1056 can out perform Marantz's flagship receiver for sound qualilty. B&K is even better in my opnion.

B&K receivers are not like your tipical Japanese receivers. In Japan , they make receivers for features first and sound quality somwhere down the road.They are not build for max soundquality and performance. Companies like Rotel , B&K, NAD are. They all build there receivers like seperates in one chassis.

The B&K avvr507s2 will out perform any japanese receiver on the market hands down. B&K has more current per channel then they have for all 7.

The B&K avr507s2 is good enough to get into the Nautilus series. I personally have done Nautilus systems using the B&K receiver with stellar results.

On another personal note , I believe your looking at the right company to drive your B&W speakers as well as the new ones down the road. For 3 grand you simply cannot beat the avr507s2

Good luck,

Dan

[billyjclark]

Dan,

I am VERY impressed with the 507 S2 receiver.....this may be the one.

I have been on the B&K website and downloaded manuals for both the Reference 50 S2 and the AVR 507 S2. Do you know what differences there are in the pre/pro sections......I can't find any (other than balanced outputs). This receiver is awesome, everything I liked about the Reference 50 is included on the 507 (3 notch filters, same DSP, Zone 2 keypad connections, same processing formats, etc...)

Seems like B&K is selling just about the same processor, but throwing in a pretty nice 150W x 7 amplifier for free! Thanks again for the tip on the 507, if I go with B&K, that is going to be the choice for me.

Billy

[Dmantis]

billyjclark,
I'll let you in on a something that some may know and I'm sure alot don't.

B&K builds there receivers from the Preamp. The Preamp section is EXACTLY THE SAME as the one in the ref50. They build there receivers just like seperates only sharing the chassis. B&K is that good and I know this as I have been to the factory and saw them built.

The only difference between the 2 is the balanced outputs. The receivers doesn't use em but the preamp does.There is no other differences.

Good luck with your upgrade. Remember also that the B&K receiver is also software and hardware upgradeable. B&K stands behind there products.

Dan

[hhcan]

B & K 507 S2 sounds warm?

Does the B & K 507 S2 sound warm or bright comparing to Harman Kardon and Rotel. I currently have the HK630 couple with Ascend Acoustics speakers and thinking of getting the either the B&K or Rotel. Some people says the Rotel sound bright so I'd like to know if the B & K would sound warm like the HK because I have a very bright room condition and prefer a warm sounding receiver.

Thanks.

[Dmantis]

I will say that B&K is yes generally on the warmer side. They do however have a pretty natural sound.

You can't go wrong with Rotel or B&K. I find both companies very high on my list. I have owned both.

Basically it sounds like the B&k will be a better choice for you. But you must listen before you buy, this is the real key.

Dan

[Hoopofficial]

HHCAN, I agree with DMantis both Rotel and B&K are great products. However, to me, they sound totally different. I prefer the B&K. Rotel 1066 with a RMB 1075 sounded very flat and had no life in the midrange. I did not hear any musical detail especially in two channel mode. I was told by my local audio boutique that the 1068 sounds totally different than the 1066. Hopefully you can do a side by side test or buy from a company that has a good return policy.