Your Martin logan Summits is excellent speakers. However, its load at high frequencies probably 5-10 times greated then that at midrange. Thus your requirments for amplifiers must match this challange.
Buyer Be Aware
Buyer Be Aware
I second the concerns indicated by Stan and Dob about the impedance characteristics of the Summit. I've seen specs indicating that its nominal 4 ohm impedance drops to 0.7 ohms at 20kHz. That variation will make its tonal balance very sensitive to the output impedance of the amplifier, even assuming the amp can handle the load. I would not extrapolate from its performance with Dynaudio's, which have completely different (and much more benign) impedance characteristics. I couldn't find specs on the Octave's output impedance, or damping factor (which equals output impedance divided into 8 ohms). That might be useful information if it can be obtained. Beyond that, I second the recommendation of trying to arrange in in-home trial. Regards, -- Al |
I did a search on the Octave forum for Martin Logans, several Octave owners have tried them. ML Aeons seem to be a good match. http://www.octave.de/forum/index.html IMHO, if I could drive B&W N800's with Octave MRE130's, you should be able to drive the ML's. Make sure you do gte the Super Black Box though. It does make a difference. Here is what I found on the Octave on the Octave english website about the V70SE: "The V 70 SE, as all OCTAVE Amps, is based on the enhanced pentode configuration. This configuration ensures the absolute stability of the amplifier against the unstable impedance of the speaker. Impedance mismatch is without consequence, as the amplifier is stable down to a 2 Ohm load. An important contribution to this stability is the Single Impedance Output Transformer. Power Output 2 x 70 Watt into 4 Ohm Frequency Response 10 Hz - 80 kHz / ± 0,5 dB Total Harmonic Distortion < 0,1% @ 10 Watt into 4 Ohm Signal-to-Noise Ratio > 100 dB Input Sensitivity 120 mV Minimum Speaker Impedance 2 Ohm Al, I have chatted with you in the past about Octave products. Here is a link to the user manual for the V70SE with lots of specs: http://www.octave.de/en/pdf/Manual_V70SE_engl.pdf Ciao, Audioquest4life |
Audioquest4life, yes I recall that discussion, in this thread. Thanks again for providing the information and the links. That's certainly a good sign that people are happy using the amp with the Aeon, although the Aeon is a slightly less difficult load (1.3 ohms at 20kHz, instead of 0.7 ohms). There are two concerns, as I see it: 1)Will the amp be able to handle the load? While your B&W N800's are a somewhat difficult load, they are difficult in a different way. I found a statement in a review indicating that their minimum impedance is 2.8 ohms, and that occurs in "the power band," which I assume means the bass or mid-bass. The ML, like many electrostatics, reaches its minimum impedance at 20kHz, and that impedance is highly capacitive. On the one hand, obviously much less energy is required at upper treble frequencies than in the bass region, but on the other hand the highly capacitive nature of the load increases its severity. 2)Achieving proper tonal balance. The lower the (unspecified) output impedance of the amp, the more prominent upper treble frequencies will be. The higher the output impedance of the amp, the more upper treble frequencies will be de-emphasized. The degree to which the speaker's tonal balance will vary as a function of amplifier output impedance will be much greater than for most dynamic speakers. So I'm not sure what the bottom line answers are, but those are some thoughts. Best regards, -- Al |
As Al says, if A drives B it should also drive C does not always hold. I have Meridian 605 amps, which are 150 watt mosfets. They never had any trouble driving my Apogee Duetta Signatures, which are known as a difficult load. But they get very hot and have to be carefully monitored driving my Gamut L5s. Most would think the Apogee was the harder load but not for the Meridians; every amp -speaker interface is different. |