Quote:Want to make sure I understand the analogy being made here:
2K vs 4K would be the difference in detail, while 30 fps vs 60 fps would be about transient response: 60 FPS offers more clarity on the top end, maybe more definition on percussive instrument attacks.
Assuming I'm reading this right (Steve, please clarify at your convenience), I'd personally opt for the 4K / 30 fps found with the UFO25 + CSP325.
I wasn't really thinking of transient response when I made that analogy --
When I look at a 60 FPS video I see more fluidity in the way things move. It has little to do with resolution of the images that are moving. I often resort to video references when trying to describe sound.
Another analogy I could use is color. The colors are bolder and richer on the Sarah but when the colors go semi-transparent so you can start to see through the color, the UFO25 shows this translucency with crystal clarity.
Over the years and especially with the UFO25 I have come to understand the Zen Triode is the amp you actually can't hear. That's it's magic. I got the Sarah as close to that as the 300B wanted to get without loosing its sonic potential.
So we think the 300B is warmer or fatter sounding than the 6P15P used in the UFO25 because that is what we hear.
There is some great irony in that because the first harmonic of the fundamental tone on an SET amplifier is always even order and in this case exactly double the frequency of the fundamental tone. This ghost note exactly one octave above the music is what determines the THD distortion %.
In my world it is the most meaningful when we look at what is happening at 1 watt RMS of output as this is where it will be during the majority of your listening session on most speakers.
You would think the "SET" sound is due to this even order harmonic since push pull amplifiers generally don't have it, and have much lower distortion in general. You would think that because an SET amp has this ghost note as high as 3% vs. the high power amplifiers that measure ten to 100 times lower that this is where the "sound" comes from.
Yet, when we look at the UFO25 at 1 watt of output the distortion is around 1% or more and the Sarah 300B at the same 1 watt of output is considerably less. Just the opposite of what you would expect based on that theory.
I think the subjective comparisons to video are at least several times more telling about the sound than the THD specification. If everyone could read the harmonics on a distortion analyzer with real meaning, like Nelson Pass as one example, then the distortion graph could begin to tell a meaningful story.
Even though I understand what I'm doing I still marvel at why and how things can sound so different. If I didn't we would only have one amplifier.