Looking for a good 7 channel amp to use with my h/k 525

Discussion in 'AV Receivers' started by Todd smith, Feb 24, 2004.

  1. Todd smith

    Todd smith Supporting Actor

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    what would I have to spend to get a good bang for the buck 7 channel amp that would be a significant upgrade to my 525? The 525 will be used as a pre/pro.
     
  2. MikeAF

    MikeAF Stunt Coordinator

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    Todd,
    I've also been looking at 7 channel amps in the $3000 range and have come up with the Sherbourn 7/2100, the Adcom GFA-7807 and the ATI 2007. Any of these amps would be great and I haven't sold my current amp yet, but I will be making a decision on one of these within the next couple of weeks. Aragon also has a 7 channel amp in this price range I believe. I know there are many happy Sherbourn users on this sight who may be able to tell you more about the Sherbourn. It will probably be the best bang for the buck of the three. Good luck in making your decision.

    Mike
     
  3. ChadLB

    ChadLB Screenwriter

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    What is your price range and have you thought about just buying a 5 channel and using the 2 channels from onboard for the 2 rears.
     
  4. Charles Gurganus

    Charles Gurganus Supporting Actor

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    Todd, a little more information would be helpful. What speakers do you use (sub?), do you run them as small, how big is your room, budget etc?

    There is a huge range for 7 channel amps from close to $1000 on up to 3 to 4k and more.
     
  5. SethH

    SethH Cinematographer

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    Look at Outlaw. They have two 7-channel amps, one for under $1000 and one for right at $2000.
     
  6. Ricky T

    Ricky T Supporting Actor

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    Why even consider a 7 channel amp? Especially, an entry level 100 wpc. Get a 5 channel amp (you have many more choices, and the option to buy used) and let the strong HK 325 drive the two rear centers. The receiver amps are at least 90x2 in stereo. I'd much rather have a 200x5 amp from Sherbourn, Parasound, Rotel, Acurus, Anthem for 900-1200 used, with the receiver on my rear centers than a 100x7 amp.
     
  7. Todd smith

    Todd smith Supporting Actor

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    My room dimensions are 22'l 11.8w 7h. I have a hsu vtf-3 (I am going to sell this in exchange for a PB2+), 6jbl s-38's all around and the s-center. In the next few years (more like two or three) I will upgrade the speakers so I would like a 7 channel amp that can grow with me in that reguard. I was hoping to stay around the $2000.00 mark if possible.
     
  8. Ricky T

    Ricky T Supporting Actor

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    Todd,

    A 5+2 combo is more flexible and can be sonically superior to a 7 channel (two power cords can draw more than one; also, two chassis can hold bigger parts than one).

    I would get a used 200x5 for $1200-1300 like the Parasound 2205 or Rotel 1095. Then, you can add their 200x2 brother for 550 used later, or even get the Parasound 3500 350x2 or Rotel 1090 380x2 if your future main speakers are worthy!
     
  9. JohnSer

    JohnSer Stunt Coordinator

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    Ricky, I have a HK520 and assumed that all of its channel amps were the same, from a common power supply. ie the surround amps (if only ones used) would have the same output specs as the stereo spec. Now that I've seen the 520 schematic, I doubt that is true. The front three channels are the same and are fed by a common transformer winding, bridge, and PS caps. The rears have their own. I suspect both have different rail voltages, as well. I haven't seen the 525 schematic, so can't say for sure, on that model. I know other HK models have similiar to the 520. The 520, because it has preouts and main-ins, you can use the "better" front channels for rear surround. I believe the 525, does not have main-ins. I run a two channel power amp for L & R, so let the center get the extra PS margin. If I had a 3 channel amp, it might be worth swapping.

    Anyhow, this is just FYI, because I agree with your recommendation [​IMG] The surrounds are usually closer and don't need the same amount of amp power.
     
  10. Ernest Yee

    Ernest Yee Supporting Actor

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    Not that I really care about defending the Sherbourn, but the 7/2100 has 2 power cords drawing in 30Amps and weighs in at ~115lbs.

    I think a nice advantage of this design is that even if you're just using 5 channels, you can bi-amp the mains w/ this setup - which you can't do for a regular multichannel amp.
     
  11. John-Tompkins

    John-Tompkins Second Unit

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    Keep in mind that some of these amps mentioned go into class "G" after about 80 watts or so (it may not be an issue for you but for some it is)..
     
  12. Ricky T

    Ricky T Supporting Actor

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    Ernest,

    The Proceed Amp5 weighs 119 lbs and is rated at *only* 125x5....yeah, right. This monster amp retailed for 5k and is going for 2k or less used. Hope some of you are considering it!

    Johnser,

    That's very true about the usefullness of mains-in/preouts! Also, suppose the 520 does 110x2 and 70x5; even if the rear amps (with 3 open channels) doesn't do the full 110x2, it should still be more than 70x2, perhaps ~ 95x2.
     
  13. JohnSer

    JohnSer Stunt Coordinator

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    Nope! On the 520, the only thing in common between the front 3 channels and the rear two, is the primary side of the transformer. And the primary side is not limiting the power to either. 75x5 means the rears are realy 75x2. Can't get more out of them because the fronts are not being used. The fronts you get 85x2 or 75x3.

    PS: I used the actual 85 and 75w rating from the service manual.
     
  14. Todd smith

    Todd smith Supporting Actor

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    Let me ask you guys this, If I were to get a 5 channel amp and use my 525 for the rear surrounds would I still get a seamless 360 degree soundfield? Is seems to me that If I am driving 5 channels at 200watts/channel and the other 2 at 100 watts (or whatever) there would be an audible sound difference. This is why I was leaning toward the 7 channel amp. Is my thinking off? Thanks for all your input and information.
    By the way, what exactly is class G mentioned in one of the threads above?

    One more thing, If I were to get something that is rated at 200 watts/channel would I not be able to use it with my jbl s-38's since they are rated to 175watts?
     
  15. JohnSer

    JohnSer Stunt Coordinator

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    Well, the "sound" of amps is definitly subjective. Some people do hear tonal differences. As far as differences in power levels, take a look at your 525 calibrated speaker levels. Most likely, your surrounds are set lower than your fronts. The ole rule of thumb, to get 3db additional output, requires doubling of amp power.
     
  16. Charles Gurganus

    Charles Gurganus Supporting Actor

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    "If I were to get a 5 channel amp and use my 525 for the rear surrounds would I still get a seamless 360 degree soundfield? Is seems to me that If I am driving 5 channels at 200watts/channel and the other 2 at 100 watts (or whatever) there would be an audible sound difference."

    Todd, just to give you an example. In my setup, I am biamping my front main NHT VT2's with 2 200 wpc from the Sherbourn 5/1500a, one 200 wpc to the center and then use a B&K ST1400 amp (about 125 wpc) for my rear NHT VT1.2's. Now admittidly, I had to push the preamp to the rears up pretty high (+4 or 5 db's I think) to match the front mains, but it is a seamless 360% sound field. Matching up the channels when using different amps/wpc does involve a few more variables but it can usually be done. I may of had a problem if I were trying to use a 75wpc amp for the rear while pushing 400 wpc to the mains but even then I would probably be able to match by dropping the output to the mains.
     
  17. Felix_H

    Felix_H Stunt Coordinator

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    You will hear a negligable difference or none unless you have a room the size of an Imax theater.
     
  18. Bob_Lawrance

    Bob_Lawrance Stunt Coordinator

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    Johnser

    You set up is similar to mine, I run a rotel rb-1070 for my L&R fronts and use the main ins for the back surrounds. It sounds pretty good. How long have you had yours set up like this?
     
  19. Todd smith

    Todd smith Supporting Actor

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    Thanks again you guys for helping out a rookie:b . John I am a little unclear, are you telling me it would be o.k. (safe) to use a 200 watt/channel amp with my s-38's?
     
  20. Felix_H

    Felix_H Stunt Coordinator

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    Todd,
    It is better to have more power than to have less power. Since your speakers are rated at 175w, you will be good with 200w from an amplifier.
     

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