Can tube amps give true high end bass?


I got the giant Silverline Grande La Folia speakers. They are really good and true high end in my opinion. They are efficient ca 93Db but got for bass 4 x 9,5ยด dynaudio woofers in each cabinet. I have tried 2 tube amps with them: Antique Sound Labs monos 2x60w and a protype VERY good 2x40W with El34 tubes (more about that amp in a later tread). And I have tried 2 transistor amps: An Ayre V1xe and Krell 450mcx monos. All givin very good sound in the mids and heigths BUT very different in bass. In my opinion the best bass was from the tube amps. Powerful deep bass!!

My dealer clames that such big speakers need a lot of power to control the 8 woofers: You must have several 100W i.e. tranistor or BIG tube amps like big VTL. With the "small" tube amps, that you have tried, the woofers get out of control and "pumping" air in an incorrect way. This movement in the woofers gives sound on it own that you only THINK is good bass!

Beeing an audiophile for 30 years I think I can determine when I hear good bass. But I am puzzled! -How can a 40W tube amp give better bass that Krell 450 monos?
ulf

Showing 3 responses by t_bone

Jmaldonado, thanks for the clarification. I guess I now have an explanation for why I like my tube amps vs others that I have tried on the relatively efficient woofers of my even more efficient speakers. I have thought about powering the woofers with solid state, but have thus far avoided it.

Another question back at you would be... how much tube power (watts vs output impedance) would one need to adequately power an 8ohm 96db woofer? say, the way a 40W solid state amp might...
Jmaldonado says...
Besides, the higher output impedance of tube amps create the conditions for slightly undamped resonance that adds to the "joy" factor. The end result is a warm, rich bass around the 40-200 Hz region to which you have become accustomed by now.

Jmaldonado, where do these "undamped resonances" come from and how do they manifest themselves? I am perfectly willing to believe the "joy factor" you mention comes from colorations, but how does "high output impedance create conditions for undamped resonances? Are they speaker cabinet resonances?

Even worst, you probably are missing the very lowest bass frequencies that only a solid-state amp can produce, and which contribute greatly to the realism of your bass playback.

Jmaldonado, please elucidate. Why would this be the case? What frequencies are we talking about? Those below 40Hz?

Regards,
Amfibius, Thank you very much for the explanation. I had ignored damping factor as a possible reason for this "resonance" because Jmaldonado talked about the amplifier rather than the amplifier/speaker interface. I realize that speaker impedance curves are (generally) not linear and for most speakers, will drop around the bass (except for my former ESLs) leading to the lowest DF at the lowest bass. I guess I automatically assume that people, especially those with low-power SETs, would seek appropriately matched speakers so they would get speakers with low DF requirements. My tube amps do quite well with my efficient and high impedance woofers, though my amps are "cursed" with very large OPTs and a surfeit of power and my speakers are designed to use low-power amps.

I wonder if that is the reason why we tube amp owners "miss" the lowest frequencies in the bass... I had thought that the main reason I was missing 12Hz was that my speakers reportedly only go down to 18Hz :^).

In any case, I would have thought that once one gets down to below 40Hz, it becomes much more an issue of the speaker's frequency curve than the amp's (if properly matched) and in the real world, anything below 60Hz and I expect that room loading/acoustics will make a mockery of the "flat frequency response curve" that an amp, tube or SS, produces.