What makes the Bloom around instruments . . .

i think bloom represents a balance between fundamental and harmonics.

using a violin or acoustic guitaras an example, bloom would exist when the wood body of the instruments was present as one observed the plucking of strings.

i don't think bloom is a treble phenomenon but rather what happens in the upper bass/lower midrange.

I don't think either the spectron or pass amps have the frequency response characteristsics i have described, i.e., i think that both amps have a transistory sound.

i have heard the spectron driving the analysis epsilon. the sound was somewaht thin.

i have owned a pass amp, but not the one discussed here.
i have heard the pass x series amps at ces.

i doubt any solid state amp can "produce" bloom.

i think classic tube products are more likely to be associated with the term "bloom", as i have described it than either current generation tube or solid state.

it could be that the pass amp is more linear in its frequency response than the spectron, which sound a bit peaky in the treble.

keep in mind my experienece listening at home is panel speakers, including quads (esl and 63s), magnepan (1.65 and 2.7) and magneplanr 1 bs.

Went for a listen to the song mentioned and my AS S30 made the organ plain to hear. If the Pass amp kills the organ then I have struck gold.

Chuck, the quote you posted from Rtn1 is as good a description of the quality called "bloom" as I have ever read (though as Elizabeth said, many call it "air," an even more vague term). To me, this is one of the most undefinable of all audio reproduction factors. I think a combination of elements contribute to it - Elizabeth, Noble, Bryon, Baranyi, and others all made good comments on it. To me, these factors add up to much more than one term could describe, but if some want to call it bloom, so be it - it has to be called something, if we are going to discuss it. For me, and for many fellow orchestral musicians, this is one of the most important qualities of sound reproduction - this bloom factor goes a very long way towards determining how "real" a system will sound. Digital and solid state have a very hard time reproducing this particular quality of instrumental and vocal timbres - as I have said before, I think it has a great deal to do with how much of the harmonics/overtones of/in these timbres are reproduced.

I have never heard one of those Pass amps - I would very much like to someday.

Fool,

If the Pass amp kills the organ on the DS song why would you want to hear it? =8>D

Let's take our audiophile hats off for a moment, and ask: In general, what do we usually think of when we hear the word "bloom"? Speaking for myself, I think of a flower. When a flower blooms, what does it do? It radiates in all directions. In music/audio, that is exactly what "bloom" means. It is the sense that the sound of a sonic image radiates in all directions. It creates a sense of dimensionality, with an audible sense of the sound projecting not just forward, but also sideways, and to the rear. Additionally, contrary to the audiophilic quest for the elusive "black space between images", there is a sense of great energy in those spaces; rich with the overtones, and undertones of each image.

That is what happens when an acoustic musical instruments play in a real space. Their sound is projected in all directions. The fundamental tones, and overtones (harmonics) of each note that is played create "difference tones". These difference tones are the result of two notes (frequencies) creating a lower tone, which is the difference in frequency of the two original notes. This process is repeated a practically infinite number of times in the course of a musical performance, creating an incredibly complex sonic soup. The ability of a component to pass that much information through is also referred to as the ability to resolve, or pass low level information. However, "bloom" is not a quality that a component should bring to the table. True bloom is something to be retrieved from a recording. The test is simple: If all recordings sound "bloomy" through a given component, that "bloom" is a distortion. Recordings are subject to the limitations of the equipment used to make the recording. In other words, not all recordings have "bloom". Some were recorded in a way, or with equipment, that will sound really flat, and two dimensional, with little sense of the expansion of overtones; without any "bloom". But the great recordings, when played back on equipment that can resolve that subtle low level information will sound, as we all know, fantastic.