Almarg/Unsound/Bifwyne: Looking at these figures again the Snapper's speaker termianls are a 7ohm tap to be pedantic about it.
Cheers George
Cheers George
Tube Amp for Martin Logan Speakers
George, if I may be a bit pedantic as well, although multiplying the 1.5 ohm specified and measured output impedance by the specified damping factor of 4.7 ohms equals 7 ohms, both the manual and this page at the Manley website clearly state that the output is optimized for a 5 ohm load. As I indicated the numbers are not quite consistent, but I would be inclined to think it more likely that the damping factor spec is inaccurate than the 5 ohm figure. In part because I note that the damping factor number does not appear in the manual, but the 5 ohm figure does. And also because maximum power ratings are provided only for 5 ohms and 8 ohms, not 7 ohms, with the 5 ohm capability being higher than the 8 ohm capability. Regards, -- Al |
Thanks George. I looked at the review and picked up the following concluding statement that "[t]he Manley's output impedance [1.5 ohms], while not unusually high for a tube amp, is still high compared with typical solid-state designs, and may therefore have some effect on the frequency response of the speaker-amp combination.—Thomas J. Norton" The reason I asked the Q is because Capdek said that the Manley does a good job with his ML ESLs. I'm sure Capdek has good reason to be happy with his Manley/ML combo. But I suspect that the treble may be a tad shelved and the bass a bit augmented -- just based on what Thomas Norton said above. Obviously, unless one measured the ML's frequency response in a controlled environment, it's difficult to know what's really going on with Capdek's rig. So, I'll leave it there. If Capdek is happy -- then that's all that matters. This has been an interesting thread. I think all of us have leaned a lot. |
OK Almarg, I'll split hairs with you. With a measured damping factor of 4.7 and an output impedance of 1.5ohms it's closer to an 8ohm tap than a 4ohm tap. But all this can change with a bit more global feed back to raise the damping factor and lower the output impedance. But then Audiophiles don't like the idea of too much feedback, so throw a Zero on it for difficult loads like these speakers the OP has and maybe be happy??? Cheers George |