Help in perfecting my home theater

[Hang man]

I have been working toward building a home theater for over five years. I will not bore you with all of the details, but bring you up to date. I just got a, 135 watt/channel, Onkyo 807 receiver to power my Klipsch speakers. I upgraded my center channel from a 100 watt baby to a 200 watt C-7. I wanted to experiment with an amplifier so I picked up a used Rotel 976. This was my first personal experience with a separate amplifier. I was very impressed with the difference it made. I used its first two channels, 60 watts each, to run my two speakers outside (my zone 2.) I then bridged the last four channels, to 150 watts, to run my RF-5's in the living room, (my zone 3.) Finally I was able to make the RF's rock. They never really had much volume with the receiver powering them.

Impressed with the difference the Rotel made, I purchased a used B & K 7270 7 channel, 200 watts/channel amp. NOT impressed. The volume I get out of the B & K is nearly the same as with the Onkyo itself. So far the only difference I note is that, via the Onkyo, I can select either a variable signal or a fixed signal. I choose a fixed signal because the Rotel had volume controls. I can only push the Rotel to about half way up before my wife gives me that disapproving look. With the B & K I can bring the volume, via the Onkyo, up to -25db without even the slightest glance from her.

I suspect that either I have not set up the B & K amp correctly, or perhaps it was abused and it cannot power like it was designed. I figured if I could rock the living room with 150 watts, I should be able to rock the whole house with 200 watts. Any suggestions of how to test the B&K amp? Perhaps a suggestion for re-configuring the receiver to work with the B&K amp?

[willland]

Hang man,

My experience with B&K amps has been overwhelmingly positive. I picked up a B&K Ref 4430(200w/ch) amp to go with my Onkyo TX-SR705 receiver(100w/ch) and the difference it made was night and day. With my RF-63's at mid to high volume, the Onkyo started to strain but adding the B&K was like adding a supercharger with the tach needle climbing quickly. The punch down low was very audible and instrument seperation was very defined. The most impressive thing about the B&K is that this is all evident even at low volumes.

Maybe some techheads will chime in but maybe the volume difference is because the Rotel has a lower imput impedance(22 k Ohms) than the B&K(33.2 k Ohms) and matches better with the Onkyo's output impedance. I don't know if I even have a clue but it sounds good. Your B&K just might have an issue because it is a very high current amp(75 amps peak to peak) with loads of power(200w/ch @ 8 ohms/375w/ch @ 4 ohms) and a lack of volume should not be the case.

Bill

[zaskarx]

I have a B&K amp 200 watts per channel. Before that I was using a 150 watt per ch B&K avr. Not much step up in way of watts but I can tell the difference. There is more head room.

I dont know how you could test the amp? I know mine kicks *** very clean effort no distortion power. If your amp is good, you may be use to distortion, that may be why your gf gives you that look. A buddy the other day was blasting music thru his tv jamming a cd, it hurt my ears and his tv is what 15 watts per channel if that. My amp dont hurt my ears. Distortion is loud. Clean loud music you can carry on a conversation with someone next to you. If there's a problem I hope you get it figured out... B&K makes great amps imo...

[Hang man]

Headroom is something I was looking for. I find the music to be fairly clear, but just as clear as the receiver alone. I was looking for two benefits of buying the amplifier; more volume and clear realistic sound. I suppose I expected that I would not have to push it past -50dB to reach an appropriate listening level. I am not trying to get to ear bleeding levels, but I like the idea of having the extra horsepower even if it is never used. While shopping for an amplifier I brought in an Andrea Bocelli cd to test various amps. I was surprised to hear sections of the cd that I had never heard before. It was the first time I heard him breath between lines. I was impressed with such clarity. I wanted that kind of sound in my system. Alas, I am not achieving that result with the B & K. To afford a better amplifier I went the used equipment route, assuming a good quality amp should last for years. Now I am second guessing my decision. In many of the ads I would read, "Pet free, smoke free home. Never abused, never run hard." If you ran an amp hard could you actually "abuse it" or "use it up"?