0.002% of distortion is a magnitude worse over witch class A, or AB amp ?
Class D use a switching frequency, and the so calling increase of distortion at high frequencies is just this switching frequency, impossible to be rejected enough by any distortiometer. Reason why you see this pseudo distortion increase with a linear slope above 1Hz or at low levels.
Just, if you have any idea of how to do it, make a spectral measure of this distortion at multiples of the fundamental frequency.
It was exactly the same that with Philips non oversampling, or delta DACs that some "audiophiles" seems to appreciate so much those days.
What does mean in your spirit harmonic distortion at 20 000hz ? Disagreeable for Dogs ?
Anyway, at this level, harmonic distortion has no meaning, and the real interesting thing is the IM.
It is interesting to notice that quite all the distortion is created by the serial self in the output, with the same kind of distortion than the one generated by the output transformer of a tube amp. At least, it is possible to make so much different designs with Class d, that it is just stupid to generalize anything about the so calling "sound" of Class D.
Did-you even listen to one ?
It is just sufficient to listen to a *good* class D amp to persuade itself how it can be clean , not aggressive, airy at high frequencies and reveals so much details lot of ClassA amps are unable to reproduce.
Do you think that Jeff Rowland or Mark Levinson are stupid ?
Let me add that i'm may-be blind, but i' kept myself away from any controversial about any treble quality, as i've only suggested to use Class D for bass and low medium. And not for the reason you can imagine. It is because, as the filter reduce the F range to 100khz, i prefer faster slewrate at high frequencies and no phase rotations, qualities that a tube amp would be unable to offer neither..
For my use, i have a current feedback amp, that i have designed and build myself, with power mosfets witch goes up to 3mhz with more than 300V/µs of slew rate. But, believe me or not, and i was surprised myself, there were not so much listening differences when i compared D amp for trebles.
Mouarrf. Spend as many years as me behind mixing desks , designing and building studios and equipments, and we will talk about managers.
Tube amps have a great dynamic, because the high tension inside the tubes. And the distortion comes gradually and softly without clipping. This distortion is mostly pairs harmonics, agreeable to the ears, witch gives a feeling of an increased dynamic. So, you can reasonably use half the power for a tube amp than a solid state one.
Peak real power equal RMS power for solid states Class D A or AB amp with regulated power supply. I agree with such amps that it is secure to stay in the same range of power for all the band up to 5000 hz. This said, most of the time, good tweeters often have a better efficieny than woofers and, so, have their level reduced in the passive filter. As an example, my circular horn with his JBL driver have 110db/w/m between 1000 to 20 000Hz. IE 12db more than the bass loudspeaker on my two ways system. So i can use 16 time less power for it for the same acoustical level.
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i dont make my own amps i´ll have to buy 2 tube amps , all the amps will have a 4 ohm load , so all drivers are 8ohm.
the bass amps are fet amps class a/b
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Oh, i wonder why do you want to use two sets of loudspeakers in the same room ? It will make a lot of acoustical problems in medium and treble for few change in level. And the real impedance risk to be very low at low frequencies.
That is non sensical.
If the tubes supply is let say 500V , what difference will this made
if the tube output signal is indeed reduced to about 50V by the
output transformer ratio, compared to a solid state amp that would
be supplied with about 50V.?....
Transistors based amps have more dynamic in fact , given that their noise
floor is an order of magnitude lower..
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AFIK tube amps operate their active devices so that the signal swing is a much smaller fraction of their supply rail than in a SS amp. This allows them to achieve very good linearity. Doug Self noticed the same thing - if you operate a SS amp with larger rails but keep the signal swing equivalent to an amp with smaller rails - you get lower distortion. I believe he published some plots showing the benefit of operating the VAS device with more -ve rails than the output devices for this reason. And hence, with a signal swing that's normally only a small part of the supply rail at average listening levels there's the potential for lots of dynamic headroom. I guess the reason not to sue high voltage rails for SS amps (other than device ratings) is power dissipation - you essentially have to build a high power amp. But people say high power amps sound better...
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Hum, before to be so definitive, please, just compare the linear part of the gain curve of a tube and the one of a transistor.
Don't-you confuse signal/noise and transient response ?
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