Holographic imaging


Hi folks, is the so called holographic imaging with many tube amplifiers an artifact? With solid state one only hears "holographic imaging" if that is in the recording, but with many tube amps you can hear it all the time. So solid state fails in this department? Or are those tube amps not telling the truth?

Chris
dazzdax


My closest experience with holography was at a NYC Stereophile show years ago. The demo was in the David Wilson room and his source was the Basis Evolution turntable. He played a cut from an LP called "Bob and Ray throw a Stereo Spectacular" in which you can "see" the butler's footsteps scale up the stairs.

David Wilson was demonstrating the differences between 3d realism from analog and how its diminished thru redbook.
Lets assume that a 200 Hz bass note is modulating the 1000 Hz note.

This will cause a 1khz tone to shift up to 1005 hz At this level it is a mere twinkle in the eye of “harmonic distortion” but is distortion nonetheless.

Not the way I understand Fourier analysis. You would not get a 1005 Hz note (this note only exists in theory or in the infinitessimally short space of time or "twinkle of an eye" and you woudl not be able to hear it as it would have no power spectrum as it does not exist over time).

I think you would end up with a 1 Khz signal with side bands at 1200 Khz and 800 hz and 1400 Khz and 600 hz etc. etc. as the non-linearity would cause IMD that had a power spectrum that relates to the mixing of the 200 Hz bass note with 1 Khz tone under a non linear amplifying condition.

The way I understand fourier analysis - shifts in time are similar to other non linearities and can be treated that way - in the same way jitter shows up as side band distortion on audio signals when jitter has a distinct periodicity to the signal (i.e not just uncorrelated random jitter that will simply raise the noise floor).
Achieving a 3-d hologram is (to me) the very goal of this hobby. It isn't an artifact...It's success. It's symetry of gear and room and a great recording. When I have Ray Brown playing that double bass in true 3-d hanging between my speakers, being able to walk around him, that's a GOOD thing.
Shadorne,

Your statement, "Lets assume that a 200 Hz bass note is modulating the 1000 Hz note."
Followed by my line – “This will cause a 1khz tone to shift up to 1005 hz”
Makes no sense – I was referring to an instantaneous shift in velocity of 1:1.005

Roger