MrMcGoo Posted January 19, 2005 Share Posted January 19, 2005 Griff, You seem to have trouble reconciling facts. I said I favored two big transformers and that is exactly what I have. One two channel amp plus one five channel amp adds up to two amps and two tranformers. The transformer on the stereo amp is huge. The 5 channel amp runs the center and surrounds. Most of the 5 channel amp's power is available to the center, since the surrounds do not usually get that much information while the center gets about 75% of all sound. I agree that all channels driven ratings are important, provided that the amp can deliver as advertised. Bill Quote Link to comment Share on other sites More sharing options...
Griffinator Posted January 19, 2005 Share Posted January 19, 2005 Wow. I just re-read my previous post for the first time. My apologies. I really lost it in that mess. In reply... I still fail to see how seven full-size transformers in monoblock configuration are somehow inferior to two full-size transformers, one for two channels and the other for 5. If you can enlighten me on this, I'm all ears... Quote Link to comment Share on other sites More sharing options...
MrMcGoo Posted January 19, 2005 Share Posted January 19, 2005 A big transformer that has seven times the capacity of the seven small transformers can play at the same level all channels driven and at a higher level when less than all 7 channels are palying at maximum. Bill Quote Link to comment Share on other sites More sharing options...
Griffinator Posted January 20, 2005 Share Posted January 20, 2005 ---------------- On 1/19/2005 7:45:26 PM MrMcGoo wrote: A big transformer that has seven times the capacity of the seven small transformers can play at the same level all channels driven and at a higher level when less than all 7 channels are palying at maximum. Bill ---------------- That didn't answer my question, Bill. I said seven large transformers vs. two large transformers. The Sherbourn 7/2100 weighs 115 pounds in-carton for a reason - they use seven massive torroidal transformers, one for each channel. How is that inferior to using two of the same size transformers? Quote Link to comment Share on other sites More sharing options...
Colin Posted January 20, 2005 Share Posted January 20, 2005 I will have to listen to the big HK AVR630 on my horns again, but I still don't think that all the expensive SS crap can sound as sweet and delicate on big ole horns as tubes, I say use a vintage or ASL tube amp for less than $1K for the La Scalas... Quote Link to comment Share on other sites More sharing options...
Olorin Posted January 20, 2005 Share Posted January 20, 2005 We know what you think about it, Colin, but please try to remember where you are. This is Home Theater. Tubes are impractical for all but the most determined in this application. A Mercedes 560 is a fine automobile, but nobody in his right mind is going to suggest you get one for pulling your horse trailer. Quote Link to comment Share on other sites More sharing options...
Griffinator Posted January 20, 2005 Share Posted January 20, 2005 ---------------- On 1/20/2005 11:25:35 AM Colin wrote: I will have to listen to the big HK AVR630 on my horns again, but I still don't think that all the expensive SS crap can sound as sweet and delicate on big ole horns as tubes, I say use a vintage or ASL tube amp for less than $1K for the La Scalas... ---------------- Of course your integrated SS receiver isn't going to sound sweet or delicate. We're talking about separates here, dude. That's like comparing a Fisher integrated tube amp to Sunfire separates. There's no competition... Quote Link to comment Share on other sites More sharing options...
MrMcGoo Posted January 20, 2005 Share Posted January 20, 2005 Griff, There is not enough room in your amp for seven big transformers. Does your manufacturer rate your amp for one and two ohm loads? Bill Quote Link to comment Share on other sites More sharing options...
Griffinator Posted January 20, 2005 Share Posted January 20, 2005 I suppose we need a definition of what exactly a "big" transformer is before we can come to an agreement about it. Meanwhile, Sherbourn specifically advises in the owner's manual against using speaker configurations below 4 ohms (or 8 ohms in bridged mode) so no, they don't offer 2 and 1 ohm load ratings. I fail to see the relevance, other than Bob Carver's old marketing trick of offering 2 and 1 ohm bridged ratings to tease the watt-fiends with massive output advertisements. (OMG! THIS THING CAN DRIVE 5800 watts per channel in bridged mono mode at 1 ohm! Wonder what I'd have to do to actually get that wattage out of it?) Quote Link to comment Share on other sites More sharing options...
MrMcGoo Posted January 20, 2005 Share Posted January 20, 2005 Many separate amps with high current capability can drive low impedance loads. It is one mark of quality in my mind. One test report (S&V) puts the RF-7s minimum impedance at 2.8 ohms. Ability to drive low impedance loads is not a gimmick IMO. The big Krells and Levinsons do it for a reason. The Sherbourn seems to be an excellent bang for the buck amp. However, there is another brand that has seven amp modules run off of two big tranformers. I suspect that it has better ability to allocate power to the channels that need it. Bill Quote Link to comment Share on other sites More sharing options...
Griffinator Posted January 20, 2005 Share Posted January 20, 2005 Actually, Sherbourn's newer 7/1250 runs seven modules on two transformers, driving 125wpc. Still doesn't rate the amp for 2 and 1 ohm loads. You make mention of the RF-7 and the 2.8 ohm minimum load impedance, but we're talking about nominal load when we talk about rating, not minimum load. Quote Link to comment Share on other sites More sharing options...
MrMcGoo Posted January 20, 2005 Share Posted January 20, 2005 If an amp cannot drive lower impedances, then frequency response is bound to suffer where the impedance dips in the bass frequencies. It is basic physics. I have heard the results with my system. The Sherbourn does 200 watts into 8 ohms and 300 watts into 4 ohms. Very respectable. The B&K 200 watt amps put out 375 watts into 4 ohm loads. Bill Quote Link to comment Share on other sites More sharing options...
Griffinator Posted January 20, 2005 Share Posted January 20, 2005 ---------------- On 1/20/2005 2:58:44 PM MrMcGoo wrote: The Sherbourn does 200 watts into 8 ohms and 300 watts into 4 ohms. Very respectable. The B&K 200 watt amps put out 375 watts into 4 ohm loads. Bill ---------------- Yes, but that 375, along with the 200, are not all-channels-driven loads. Steve Konopa, a B&K owner, can attest to that.... Quote Link to comment Share on other sites More sharing options...
MrMcGoo Posted January 20, 2005 Share Posted January 20, 2005 Griff, The B&K cannot do 375 x 7 channels because it equals more watts than a 20 amp circuit can provide. The point is that the B&K can follow the impedance curve of the speaker at any rational listening level. Solid state amps are constant voltage devices. If an impedance dip causes an amp to try to put out more current than it has available, the voltage will drop and frequency response will suffer etc. Bill PS: Total watts are not so important on highly efficient Klipsch speakers. What is important IMO is a clean first watt and the ability to follow the impedance curve of the speaker under a dynamic load, i.e., transient response. B Quote Link to comment Share on other sites More sharing options...
Tom Adams Posted January 21, 2005 Share Posted January 21, 2005 Since I own and have listened to a Sherbourn 7/2100A, I'll weigh in here with this.... If one big as* transformer is the cats' meow, why are there so many testimonials here and elsewhere from folks running monoblock amps - both SS and tube? And I would suggest that the chances of a speaker load dipping down to 4 or 2 or 1 ohm is slim to none. Remember...we're talking HT here and in that regard, your mains will not be handling those huge current sucking low frequencies. Those lows will be handled by your sub. So, IMHO, any HT amp rating their output into 4 or 2 or 1 ohm is meaningless to me. The B&K is no doubt a fine amp as is all of the other mentioned in this thread. However, my perception McGoo is that you're aguing just for the sake of arguing. I don't think you'd ever get 10 amp designers to emphatically agree that one amp topology is the only way to skin a cat. Which is very close to what you're trying to imply with your comments. Yes? No? Tom Quote Link to comment Share on other sites More sharing options...
Griffinator Posted January 21, 2005 Share Posted January 21, 2005 ---------------- On 1/20/2005 10:33:47 PM MrMcGoo wrote: Griff, The B&K cannot do 375 x 7 channels because it equals more watts than a 20 amp circuit can provide. The point is that the B&K can follow the impedance curve of the speaker at any rational listening level. Solid state amps are constant voltage devices. If an impedance dip causes an amp to try to put out more current than it has available, the voltage will drop and frequency response will suffer etc. Bill PS: Total watts are not so important on highly efficient Klipsch speakers. What is important IMO is a clean first watt and the ability to follow the impedance curve of the speaker under a dynamic load, i.e., transient response. B ---------------- You brought the watt rating issue up just to trump the Sherbourn. Now you backpedal and start explaining away the point I raised. Funny, the Sherbourn is set up with two AC cords, specifically so it will have 40 amps worth of current draw available. You sure the Sherbourn is set up with mini-transformers? I doubt it. I'm fully cognizent of the fact that highly efficient speakers like Klipsch require a great first watt more than they require megawatts of power. Once again, you brought up the power issue, now you're backpedaling off of it. I concur with Tom - you're just arguing for the sake of arguing. Quote Link to comment Share on other sites More sharing options...
MrMcGoo Posted January 21, 2005 Share Posted January 21, 2005 I am sticking to the point that larger transformers have some advantages. I have not been given any evidence to convince me to change my view. As to other points-The RF-7s have impedances that dip to 2.8 ohms per Sound & Vision Magazine of May, 2002 on page 50. Other Klipsch speakers in the same seris were measured with minimum impedances from 3.1 ohms to 3.6 ohms. Home Theater Mag. puts the minimum impedances of the Reference 7 series a few tenths of an ohm higher. So, please do not tell me that they do not go below 4 ohms. All that I have been driving at is that two big transformers can use a 20 amp wall outlet's power at least as efficiently as 7 individual transformers in the same box. That is why I have referred to several other brands. Seven true monoblocks are not really a useful comparison, since most folks do not have space for them. The topic under discussion was the best configuration(s) for multi-channel amps. Bill Quote Link to comment Share on other sites More sharing options...
Griffinator Posted January 21, 2005 Share Posted January 21, 2005 ---------------- On 1/21/2005 9:22:28 PM MrMcGoo wrote: All that I have been driving at is that two big transformers can use a 20 amp wall outlet's power at least as efficiently as 7 individual transformers in the same box. Bill ---------------- Fine, but you have no evidence to prove that they can do it more efficiently, only your own hypothesis. Let's just leave it at that, ok? This discussion is getting stale. Quote Link to comment Share on other sites More sharing options...
MrMcGoo Posted January 22, 2005 Share Posted January 22, 2005 At this point I think that each reader can make up his or her own mind about the merits on either side. My goal was to provide an alternative point of view. Bill Quote Link to comment Share on other sites More sharing options...
rvincerob1 Posted January 22, 2005 Share Posted January 22, 2005 I'm so glad to read a post from a SS user! I could not be happier with my amps (Kenwood Basic M2A 220 per channel)the best 2 channel I've ever owned. I've had the Adcom 5303 3 channel, 200wpc, and i've owned the acurus MCA5 200WPC 5 Channel amp. For some reason the older SS Amps sound much better than the newer ones. Quote Link to comment Share on other sites More sharing options...
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