Rolling Pentodes Under the Xmas Tree
Exploiting a longer than usual break from work, and a generous opportunity offered by @takacs75 I indulged myself with some tube amusement over the last few weeks.
More specifically I focused on the pentodes, and I could compare the P17c (SFR), E55L (Mullard) and EL81 (Tungsram) on my Horizon360, which I use in single ended mode to my Riviera Labs AIC-10. My listening sessions involved headphones and, for the most part, speakers stints (Diesis Aura).
To make things even more fun, during the same period two major changes occurred in my system, namely the arrival of the Taiko Olympus and the installation of room treatment, both of which had a larger impact on the sound than tube rolling, forcing me to redo the pentodes assessment multiple times.
I listen mainly to acoustic music. Timbre naturalness, ambience reconstruction, transient (attack and decay) structure and ease of dynamics are my main priorities.
I found all three tubes as eccellent performers, belonging to a similar tier of technical and musical prowess (which already speaks in favor of the much cheaper EL81). All of them offer an upgrade compared to the stock KT150 that came with the Horizon, which, in direct comparison, sounds a bit grey-ish and unrefined.
The E55L is the most dynamic, it conveys energy to the music with a sense of cogency and purpose without being fatiguing or strained. Transients have sharper attacks, yet still a natural, rich decay. Upper midrange, and treble are the most neutral, with a touch of shimmer on top which illuminates details in the music. Instrument separation and the rendition of spatial cues are top notch.
The EL81 is softer and bloomier. It emphasizes body in the bass and midrange response, loosing some focus in comparison to the E55L, yet making listening pleasingly relaxed, and more tolerant of less-than-perfect recordings.
The P17c is somewhat in between the two, it has the most refined and naturally organic midrange response. Bass is not as tight as the E55L but it has more volume and still retains articulation and tunefulness. Treble is perhaps a hair less prominent than the E55L. Soundstage presentation is on par with the E55L, but different in style, lending to a more cohesive blending of instrument on display.
I could not declare a clear winner, for example when listening over headphones and using the Taiko Extreme I sensed that the E55L was a bit overwhelming, and - on the opposite - when using the Aura and a configuration of my room treatment with a lot (too much) of absorption, the E55L became my favorite.
Now I tend to believe that the P17c are the best balance in my current condition, but this exercise confirmed me how system-dependent (let alone subjective factors) evaluations become at this level.
Exploiting a longer than usual break from work, and a generous opportunity offered by @takacs75 I indulged myself with some tube amusement over the last few weeks.
More specifically I focused on the pentodes, and I could compare the P17c (SFR), E55L (Mullard) and EL81 (Tungsram) on my Horizon360, which I use in single ended mode to my Riviera Labs AIC-10. My listening sessions involved headphones and, for the most part, speakers stints (Diesis Aura).
To make things even more fun, during the same period two major changes occurred in my system, namely the arrival of the Taiko Olympus and the installation of room treatment, both of which had a larger impact on the sound than tube rolling, forcing me to redo the pentodes assessment multiple times.
I listen mainly to acoustic music. Timbre naturalness, ambience reconstruction, transient (attack and decay) structure and ease of dynamics are my main priorities.
I found all three tubes as eccellent performers, belonging to a similar tier of technical and musical prowess (which already speaks in favor of the much cheaper EL81). All of them offer an upgrade compared to the stock KT150 that came with the Horizon, which, in direct comparison, sounds a bit grey-ish and unrefined.
The E55L is the most dynamic, it conveys energy to the music with a sense of cogency and purpose without being fatiguing or strained. Transients have sharper attacks, yet still a natural, rich decay. Upper midrange, and treble are the most neutral, with a touch of shimmer on top which illuminates details in the music. Instrument separation and the rendition of spatial cues are top notch.
The EL81 is softer and bloomier. It emphasizes body in the bass and midrange response, loosing some focus in comparison to the E55L, yet making listening pleasingly relaxed, and more tolerant of less-than-perfect recordings.
The P17c is somewhat in between the two, it has the most refined and naturally organic midrange response. Bass is not as tight as the E55L but it has more volume and still retains articulation and tunefulness. Treble is perhaps a hair less prominent than the E55L. Soundstage presentation is on par with the E55L, but different in style, lending to a more cohesive blending of instrument on display.
I could not declare a clear winner, for example when listening over headphones and using the Taiko Extreme I sensed that the E55L was a bit overwhelming, and - on the opposite - when using the Aura and a configuration of my room treatment with a lot (too much) of absorption, the E55L became my favorite.
Now I tend to believe that the P17c are the best balance in my current condition, but this exercise confirmed me how system-dependent (let alone subjective factors) evaluations become at this level.
