The Summit has 2 B&O ICEpower ASC200 amp modules. They are rated at 200 watts into 4 ohms. This is the same amp used in the Bel Canto S300i integrated, PS Audio C100 integrated, PS Audio A100 amp, Red Dragon Amp1 monos and many other products.
Martin Logan woofer amplification
I was discussing a possible trade in for my Martin Logan Montis speakers. The store owner was reticent, stating that the amplifier for the woofer was an OP amp. I was surprised to hear that, since the operating space is so large. I thought it was a Class D switching amp, which should work well in a non ventilated cabinet, and operating at a low frequency. Any Martin Logan experts out there?
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I based my above assumption on this review. Here is the paragraph: "The Summit's active amplification includes toroidal power transformers, as part of a high performance bipolar amplifier that is said to offer better tracking of the input signal and reduced hysteresis. Other claimed benefits are a more open, dynamic performance than would have been expected with otherwise similar IE transformers, especially at high levels. In general terms, bass performance comes closer than previous designs to matching the speed and transparency of the electrostatic mid and treble. The hard built crossover is derived from the network used in the Statement, with air core inductors, audiophile grade polypropylene caps and point-to-point hard wiring." |
My guess is that the reviewer of the Summit was using the word "bipolar" in a very loose sense, perhaps without fully understanding what a "bipolar amplifier" is. For that matter, I don't fully understand what it is :-), and it seems like ambiguous terminology at best. I would expect that in general it would refer to an amplifier which uses bipolar (NPN or PNP) output transistors, as opposed to FETs. The ICEpower modules use some bipolar transistors, but not as the power transistors which drive their outputs. But perhaps he was using the term in reference to how the two ICEpower modules are used in conjunction with each other, perhaps in some sort of a balanced configuration. Although I'm not sure that makes sense either. Best regards, -- Al |
Martin Logan says: "MartinLogan's dedicated in-house design and engineering team created an extremely precise 24-bit Vojtko DSP engine in conjunction with a powerful 200-watt class-D amplifier to deliver a stunningly detailed low-frequency performance reaching down to 29Hz—uncommon in cabinets this compact." |
A few years back, I switched amplifiers to Bel Canto Ref1000MKII's to drive my Summits. There was an incompatibility between the amps and the crossover in the Summits that Martin Logan was aware of. I called them up and the sent me out two small replacement circuit boards. I had to disassemble the cabinets and I saw the ASC200 boards with my own eyes. |
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