Your Magnepans will be happy with the 500 watts you show at 4 ohms as that is what they are rated for. I have an older pair of completely re-done SMGA`s with different crosover circuits. They are powered by 300 watts per channel and I just went to a friends home who got his set of 3.6`s and they are powered by a McIntosh 352 at 350 watts and they sing!! Don`t see any reason to push them any harder than 500 watts. |

When biamping you need to replace the OEM XO. On the cheap is either the DBX or Behringer CX 2310 or a bit more expensive Behringer DCX 2496 |

Actually, 500w is about the minimum that I have used that will open up Maggies. As any Maggie owner will tell you, "more is better" as far as power goes. Now, I have not used the Classe's before, but I would suggest using them in a mono configuration and you should be more than fine.
I tried 12 different amps with my 3.6R's before I found my current, and final configuration. Good luck, don't be afraid to try something else if you are not getting what you want. |

I drive my 3.6's with a McCormack DNA-500 at 500 @ 8 ohms, 1000 @ 4 Ohms. They(3.6R's) act like teenaged football players. The more current you feed them, the more they take and the better they play. I have fooled with other amps, but to my taste I like the McCormack sound with my setup. Like in Young Frannkenstein, "More power Igor....."!!! I agree with Mac that you might want to listen to some other amps to see what floats your boat.
Good luck. Enjoy the music. |

Macdadtexas, could you list what the 12 amp's you tried with the 3.6's and why you finally chose Cary? Thanks. |

1) NAD 218 THX (not enough juice)
2) Parasound 3500 (lots of power, a bit bright)
3) Parasound A21 (v nice, warm, full)
4) Parasound JC1's (sublime, very full rich sound)
5) Innersound ESL 300 (massive power, never runs out, very detailed, great match)
6) Bel Canto Ref 1000's (massive effortless power, very detailed, not warm)
7) McIntosh 501's ( not a match, sounded muddy )
8) Cary Audio 500MB's (tube like sound, HUGE Bass, great match)
9) Bryston 7B's (power, nice, but not my favorite)
10) Pass Labs X 350's (good amp not my favorite)
11) Spectron Musician III ( I bought after I alreay had the Cary to try it out, nice, but to my ear, not as detailed as the Carys)
Sorry, it's only 11, unless I forgot one?? Cary's are my favorites, I also loved the big Parasound JC-1's and the Innersounds. The only amps I had that just didn't match, and it could have been with my other gear, were the McIntosh and PassLabs. |

Ahh, I forgot, because I only had it for a short time, the Musical Fidelity NuVista power amp. So that's the 12th one. I didn't like it with the Maggies. I sold it to a buddy with Linn speakers and it sounded great. I think he still has it, they are hard to find amps. |

Answers to your questions:
" I was wondering, if I "bridged" my power amp to function as "monoblocks" to drive a pair of magnepan 3.6. Will it cause the amplifier to "see" a 2-ohm load? Does that stress the amplifier's current capacity and will the amp be overheated?"
Many people state that when using monoblocks then amplifier will "see" the half of the load of the speakers. Never understood what they mean since impedance is the INTRINSIC property of the load.
What will happenned is that your maximum voltage will double (and thus maximum current will double) which will sharply decrease all kind of distortions associated with full output of the amplifier - and its huge number of distortions and all of then ugly.
So , no you not only will not stress your amplifier(s) but opposite - you will run them at half output with much less distortions - you will have much more relaxed presentation yet with deeper bass and greater slam and if you will be capable to run both in fully balanced mode then your will hear music without practically any electronic distortions in all its sweet glory. Your bandwidth will double, your slew rate will double and many other audioable goodies will be shown.
Just do it right and you will never be sorry again! If Spectron Audio done it then everybody can do it! Simon
Simon |

It sees half as much impedance because it has to supply twice as much current for a given voltage. With most amps the red speaker terminal swings back and forth from plus to minus while the black is fixed at ground potential. So lets say at some instant your red terminal is at 8V across 4 ohms and you'll have 2 amps of current flowing. If bridged to mono you'll be hooked to the other channel's red terminal which will be at -8V while the other is at +8V for a total of 16V across the 4 ohms which causes 4 amps to flow. If you ask 8V to supply 4 amps it is seeing a 2 ohm load. |

"It sees half as much impedance because it has to supply twice as much current for a given voltage"
Well if voltage is given but current is doubled then impedance should drop to the half - BUT it cannot be because speaker impedance does not depend on amplfier, weather and other extreneous factors.
In your own example - 16 volts across 4 Ohms - supply twice more current,4A, then 8 volts across THE SAME load, 4 Ohm i.e. 2A.
Just follow the Ohm law (V=IxR) and everything will be just fine. |

You missed the point. You no longer have 8V across 4 ohms when you are bridged.
When it was not bridged it was 8V across 4 ohms for 2 amps. As you say, Ohm's law. Bridged you have 16V across 4 ohms so 4 amps. The difference between +8 and -8 is 16.
plus 8V------- 4 ohms ------- minus 8V so 4 amps will flow.
The 4 amps flows out of one terminal and into the other. If each terminal is developing 8V but supplying 4 amps then it is effectively a 2 ohm load. 8/4 = 2 = ohm's law.
Back to the original question, will this stress the amps? I think not. Your amp is capable of delivering a large amount of current as evidenced by the 1,600W rating into 4 ohms. Your ears would start bleeding before you got close to that limit. Try it and see how it goes. |

Hello Herman,
Spectron was the only one in this thread who answered or tried to answer the questions posed by Vinhd.
He also expressed some irone in old expression that "amplifier see...." Amplifier does not have glasses to see and must obey Ohm law as each and every one must.
and word "voltage" really means difference in electical potential and as you pointed out in your example if at one end there is 8 volts across 4 Ohm load and on another also 8 volts then total DIFFERENE in electroncal potential is 8+8 and rest you can count.
Can you can add something to the questions posed in this thread - we all would love to hear it. Otherwise its kindergarten. |

I have operated various power amps "bridged" over the years. Most of the time it was to drive a center speaker bridged across a stereo amp that was simultaneously driving a pair of front speakers. (Invert one channel's signal to do this). The resulting load was always well below what the amp was rated for, but I never had any problems. I think this is because with the two channels driven out of phase the power supply is evenly loaded on plus and minus rail voltages. |

rmlfour, you clearly don't understand basic electronics any more than Spectron does and clearly didn't comprehend the original questions, both of which I answered contrary to what you stated.
Vinhd asked if the amp would see a 2 ohm load. It does. Spectron said it did not not. Since Spectron gave the wrong answer I fail to see why it was wrong to correct him and therefore correctly answer the question. Your smart ass comment about the amp not wearing glasses demonstrates your lack of understanding. The expression "the amp sees" is a widely used one and understood by those who understand basic electronics which you and Spectron do not or we would not be having this conversation. When we say an amp sees a certain load we mean it is equivalent to that load. For instance; if you hook up two 8 ohm speakers in parallel to an amp it is effectively a 4 ohm load so it is common to say that the amp sees a 4 ohm load.
The fact that I corrected Spectron and used basic math to do so does not make it "kindergarten." How else can you try and explain a basic math problem without resorting to basic math? Yes, voltage is a difference of potential. After teaching basic electronics for almost 10 years I have a pretty firm grasp on that concept. That concept is exactly where you and Spectron are missing the point. You are hung up on 8V and 4 ohms when in reality we now have a difference of 16V which is the DIFFERENCE between +8 amd -8. In my example the difference of potential was 16V across a 4 ohm load causing 4 amps of current to flow. Each terminal is developing 8 of those 16 volts. An amplifier that is developing 8 V and has 4 amps of current flowing "sees" a 2 ohm load. I'm sorry you can't grasp that concept but that is as simple as I know how to put it.
If you go back and read my last post I also answered the question posted "Does that stress the amplifier's current capacity and will the amp be overheated?"
It is humorous that you chose to scold me because you believe I did "not add something to the questions posed in this thread" when I clearly addressed both parts of his question and your post added nothing but incorrect information and condescending remarks. |

I know this was a question about amps for Maggies and how they sound, but I am now afraid that I need to take notes for an upcoming exam. Will we be able to use our notes on the exam, and do we have to show our work?? |

Since Spectron gave the wrong answer and after he was corrected insisted he was right with a condescending comment implying I didn't understand basic electronics, and someone else jumped in with a smart ass response defending his wrong answer, how else would you have replied other than to give a detailed response? Just let it go so Vinhd was left with the wrong answer?
I always required my students to show their work. Formula sheets will be provided so you will not be able to use your notes. |

Herman, I went to grad school at Rice and we had an honor system for exams, so I am going to ask to bring mine home!
I think this has been my favorite string to watch over the last week, maybe better than the election as far as banter back and forth. |

I have also been entertained by it. You would think that someone who represents Spectron amplifiers would take the time to get the right answer on a basic electronics question before sticking their foot in their mouth twice. His comments about reducing all types of distortion as well as bandwidth and slew rate doubling were also incorrect but I figured if he didn't understand the simple stuff there was no reason to go into anything else. |

Thank you so much for all of your help and advice. I appreciate you all taking your time and consideration in thoroughly answering my question. And again thank you. |

I've got a similar setup with bridged Plinius (which run hot normally) for planar magnetics. No problem. Maggies are nearly a purely resistive load across the bandwidth. |

If you have 2, I would stronlgy consider bi-amping with an active crossover. The main 2 people talk about using with Magnepans are the Bryston (1 model) and Marchand who have at least 3 that apply at different price points. From what I've been told this makes a gigantic difference. Personally I'm driving my 3.6s with an older Pass model, lower wattage (Aleph 5), and absolutely loving every minute of it. |