Class D is just Dandy!

Where do you get your data on the Scintillas?

Sorry my bad on the phase, looked at the graph wrong.
But not on the impedance, still 1ohm in the bass, and again it seems from your measurments at 1.3khz, no place for class-D or tubes or Mosfets, they will behave like tone controls or just give up.

"True, you could with some effort, re-wire your Scintillas at home for 4 ohm operation, but with a 6dB loss in voltage-rated sensitivity. At 1 ohm, MC estimated the sensitivity to be 73dB/1W, noting that, ’Consideration also needs to be given to the peak current demand of the Scintilla at 1ohm. Taking an average impedance of 0.9ohms, a Krell KMA-200 on full song will provide up to 60V peak. Assuming minimal cable losses, the Scintillas will draw peak currents of over 60amps. Now you can see why blockbuster amplifiers of Krell current capacity are required for 1ohm working.’"

Cheers George

George,
I bet that combo sounds spectacular.

Should have seen/heard the 90’s system, similar amps but water cooled, doubled stacked Acoustat 2’s with Magnat Plasma MP-02 Tweeters above 10kHz. esl panels crossed over at 80hz to Kef B1814 bass drivers in ported 12cu ft encosures FS at 18hz, tuned by the man himself Neville Thiele (rip), some rich dude from Singapore came to Australia just to buy it all from me, after it was reviewed in Stereophiles sister mag in HK.

Cheers George

Erik,

There is no misunderstanding at all and I apologize for my writing not being very clear at times. I understood completely what you asked, and that is you want to see is the real frequency response plot of the amp while driving such a load and also to determine what the 3 dB points are for both frequency extremes. Again, the answer is NO. I have not done the measurement. Because of the output filter of the icepower, and most of class D amp, I would speculate that there will be some high frequency attenuation at very high frequency due to the impedance raise of the inductor.

What I meant by lowest output impedance of the amp, especially completely flat up to the extreme treble region, is not necessarily always good is that it depend on the system. IMHO and IME, extreme low output impedance amp does not sound very good when mating to a highly damped loudspeakers. This is the very reason why tubeohiles really object to solid state amps, especially those with lots and lots negative feedback, to lower output impedance and distortion. The end result of such mating results in a sterile and one note bass and everything is too tightly control. Therefore, there is not much left in terms of air around instruments, much smaller soundstage, Closed-in midrange,
harsh and sterile treble etc... I am speaking strictly in terms of conventional discrete transistor design. I have designed, built, test, tried this and tried that for as long as I can remember. I agree with you about experience. There is no substitute for that.  Also, Absolutely! Apogee did put Krell on the map for sure.

Henry

Henry,
I would be more inclined to measure the in room response of your speakers and see what you get.

Kenny.

John,

It is very rare to find a Scintillas owner.  Are you located in Texas? 

Henry