5-channel vs. 3+2-channel amplifier setup

Discussion in 'Archived Threads 2001-2004' started by MiltK, Jul 9, 2001.

  1. MiltK

    MiltK Stunt Coordinator

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    Just recently made the move to separates. Already ordered the pre/pro (Theta Casa Nova) but would like to get some advice on the amplifier setup. Is it better to have a high-end 5-channel amplifier (e.g., Bryston 9B-ST, Theta Intrepid, etc.) or a 3+2-channel amp setup (e.g., B&K Ref 2220 + Ref 3220)? Space is not a concern but sound is. I am planning on eventually going to a 7-channel setup but not in the short-term (not enough software).
    Any help would be appreciated.
    Thanks!
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    "I not giving her the shot - you give her the shot!"
     
  2. Phil A

    Phil A Producer

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    Before advising, it would be helpful to know what type of speakers you are intending to drive and, how efficient they are, what type of load they present and how big the room is. My understanding of the Theta is that it is an Ayre made for Theta. If you are using the Bryston 9B-ST to drive something of low impedence of average or less efficiency is a big room, I might be more inclined to go with the 3/2 set-up if Bryston is what you like or maybe consider something like a Proceed Amp5. If you have speakers that are not too difficult to drive and not in a huge room, the new Linn 5 Channel amp looks pretty nice too.
     
  3. Frank_S

    Frank_S Supporting Actor

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    Milt, are you a 2-channel lover?
    If so, I recommend a 3+2 amp approach. You'll also have more flexibity down the road, say if you want to get an even better 2-channel amp for music or go to 7-channel for movies.
    Theta makes an excellent 5-channel amp(Dreadnaught)
    BAT also makes an excellent 5-channel amp, both of these are modular too.
    I own Aragon amps which are very nice. They double their power output at 4 ohms and are competitively priced.
    You may want to consider used amps. Audiogon and Ebay have listings you could check out.
    Whatever approach you take I would strongly recommend matching all channels with the same power output and manufacturer. Good luck! [​IMG]
     
  4. Justin Doring

    Justin Doring Screenwriter

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    All things being equal, the fewer channels per chassis, the better (e.g. monoblocks are best, stereo amps are second best, three channel amps next, and five channel amps are the most compromised). However, if you were to give me the choice between a Theta 5 channel or a 2 and 3 channel B&K, I'd take the Theta, as it's a far better amp.
    Since you're getting a Theta pre/pro, the Dreadnaught seems like a no brainer, as it matches and is one of the best 5 channel amps on the market. I haven't heard much about Theta's lower powered amp, but the extra wattage of the Dreadnaught will be welcome with virtually any speaker. If you want 7 channels, why not get three 200wpc modules for the fronts and four 100wpc modules for the rears?
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  5. Grant B

    Grant B Producer

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    Milt
    I have the Sony ES 9000 Pre/amp combo...actually 2 of the amps. They are a great value and built like a Sherman tank.
    They have a "2 BTL channels +1" Mode which really works fantastic. It also has a "extra 2 channel input" for hooking directly to a 2 ch variable output (CD etc).
    I managed to get both for under $1200...1100watts or so.
    Just a suggestion
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  6. Jay H

    Jay H Producer

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    If space is not a problem, I'd second the use of the 3+2 setup, I have a Bryston 3BST and a Parasound HCA-1203a (my previous 3-channel amp) and it's great. My system is primarily audio anyway. One thing that nobody mentioned yet is if one amp goes bad, you have the other one to listen to 2-channel stereo. Which is what is happening to my Parasound right now. The middle channel has gone intermittant and I might have to get it serviced. When I do, at least I wont be stuck without music although my HT would be toast though.
    Jay
     
  7. Andrew_S

    Andrew_S Auditioning

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    Milt:
    Check out the Sherbourn 5/1500. (http://www.sherbourn.com) Essentially, it's five monoblocks in a single chassis - seperate torroid transformer for each channel. 200wpc. And can be had for around $1400. I can't give you any long term impressions yet because I've only had mine for 2 days, but so far it's awesome....
     
  8. MiltK

    MiltK Stunt Coordinator

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    All - thanks for all the replies. [​IMG]
    Phil A - I currently have a 5.1 setup with the following:
    Mains - M&K S-1Cs
    Center - M&K S-125
    Surrounds - M&K S-125
    and a SVS 20-39PC sub
    All speakers are 4 ohm loads. The S-1Cs are rated to 400 watts, the S-125s up to 200 watts. According to the SMR Theater website review, the sensitivity of the S-1Cs is 90 db/w/m. Not sure about the S-125s but my guess it's close (88-89 db/w/m).
    Hope this helps!
    miltk
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  9. Rachael B

    Rachael B Producer

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    I use 3 power amps for my 6.1 set-up. I believe that 5, or more, amp channels on the same chassis concentrates the heat. Spreading out the heat is good IMO. Unless there is a discrete power supply for each amp channel, seperate amps will likely be better. My front channels are powered by a 3 channel amp. That's the most I'd want in one component, proably...Best wishes!
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  10. Phil A

    Phil A Producer

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    Miltk - I would also 2nd the 3/2 opinions. I use a Proceed HPA3 for the front channels and a BPA2 for the rears which is upgradable to a BPA3. Not that I am knocking 5 channel amps at all. The reason for my questions is that a friend just got the 9B ST (he previously had a 3BST in a music only system and I have owned a 4BST and power pac 120s too) and with Thiel 2.3s (4 ohms and 87db) and SCS3 center with Frieds in the rears for now and I would not say that he is at all disappointed but that he now understands what I was trying to tell him about the demands of HT. He moved and had a music system in the living room and a small HT in the family room of his old house and how has everything in his new family room which I would gauge at slightly bigger than average (maybe 14x20 with a high sloped ceiling and open via a walkway and half wall to the kitchen and eating area). When I had a 5 channel amp in the room with my old speakers (Rotel 100Wx5)I did have shut off problems with certain movies and then got the Bryston 4BST for the fronts and found that the other amp had no problem running the center and surrounds. The Theta, Bryston, Proceed, etc. when then do 5 channel are at least true mono designs and don't share power supplies in the same fashion as less expensive models. I just would not want you to invest in something and then not be happy with it. I've had quite a few amps in my HTs and to get good results I would not skimp on the amps. I have a more modest bedroom system and when I put something in the basement when I finish it I don't need the level of my current main system but I will make sure that I don't underpower the system in such a large space.
     
  11. JohanK

    JohanK Second Unit

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    I have a decent size room for my basement HT (about 2300 cubic ft. with a large opening) but have never had troubles with 5 channel amps overheating and shutting down (have, at some point, run HK PA5800 (80x5) and Rotel 985II (110x5); speaks at sensitivity of about 90 with nominal impedance at around 5 ohms).
    Arguments for stereo amps or monoblocks usually center around separation issues whether it be crosstalk, heat or power supply issues. IMO, a well designed 5 channel amp negates these supposed advantages. Crosstalk in quality 5 channel amps is below the threshold of human hearing, heat dissipation can be handled by adequate heatsink area and power supply issues can be covered with large transformers and adequate capacitors.
    One big advantage of monoblocs or stereo amps is the reduced weight in relation to comparable 5 channel amps (Class A stereo amps are quite heavy though due to their large heatsinks and power supplies).
    IMO, a quality 5 channel amp will lose nothing to comparable 2+3 configuration. That said, I run a 2+3 configuration with a Parasound 2003A and a Lexicon 212 (a Bryston 3B-ST)...go figure. [​IMG]
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    http://www.hometheaterforum.com/bbs/equipment/28687.html
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  12. Greg_W

    Greg_W Stunt Coordinator

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    Milt, I would agree with the above posts, that if space is not an issue that the 3+2 option is probably the better option. I saw that you were looking at the Bryston 9B, one thing you may not know about it is that you can order it with anywhere form 2 to 5 channels. I picked up mine with only 2 channels due to a limited budget, but can add another channel or two when I get some money. Anyways, the cost of the chassis is only about $100can and a channel is about $1050can. If you are thinking of upgrading to 6.1 or 7.1 in the future, you whould be able to add identical module(s) to one of the amps. Just a thought
    Greg
     
  13. JohanK

    JohanK Second Unit

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    Greg, bit OT, but one can really buy just the chassis for the Bryston 9B-ST? For $100C??? Do you know what is included?
    This may be perfect for my brother who want to build some home brew amplifiers.
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    http://www.hometheaterforum.com/bbs/equipment/28687.html
    [​IMG]
     
  14. Greg_W

    Greg_W Stunt Coordinator

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    Milt, unfortunanty, the 9B chassis has no actual heatsinks. The heatsinks are internal and built into the amp module. The chassis only contains the hardware for soft starting the amp and 12 volt trigger. Each of the amplifier modules is alot like a computer card, completely self contained with it's own torroidal transformer. The empty bays in my amp are blanked off, and the amp looks quite good, far more substantial looking than the 3B, but with the same power.
    Greg
     
  15. Greg_W

    Greg_W Stunt Coordinator

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    Milt, sorry, I forgot to answer one of your questions. I dont believe that you can buy just the chassis, I think Bryston sells it with only two channels or more.
    Greg
     

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