Tube Amp Recommendations $1500

5-27-14: B_limo
... it's time to start researching tube amps in the $1500 price range.

I'm looking for something that looks good, has more power than my Prima Luna 5, and has that charecteristic warm, lush, textured and detailed sound.

05-27-14: Fjn04
LM Audio 211 or 219. The former uses EL34, the latter KT88!

Aren't the Line Magnetic models integrated amplifiers? It appears that B_limo is looking for a power amp, to use in conjunction with his Lightspeed attenuator.

Also, I believe "219" should be "216," with both model numbers being followed by the letters "IA." And neither meets the stated criterion of being more powerful than the Primaluna Prologue Five.

Finally, I'm not sure that a tube amp would be an optimal choice for use with the particular speakers. If the speakers are the same model or have an impedance curve similar to that of the Paradigm Reference Signature S2 (see the first figure) the interaction of their impedance characteristics with the relatively high output impedance of most tube amps will result in an over-emphasis of the 1 to 2 kHz area, and an under-emphasis of the mid-bass, assuming (as I suspect) that the speakers were designed with solid state amplification in mind.

Regards,
-- Al

Bruce, to clarify, my main concern with pairing a tube amp with your particular speakers is not related to power, sensitivity, or volume. It is related to tonal balance. The variation of the speaker's impedance from 3.6 ohms at 180 Hz to well over 20 ohms at critical mid-range frequencies will cause the tonal balance of the speaker to vary significantly depending on the output impedance of the amp. Nearly all solid state amps have negligibly small output impedances, while most tube amps have output impedances that are significant in relation to speaker impedances. In this case the result would be that a tube amp would give greater emphasis to some mid-range frequencies than a solid state amp, and would de-emphasize mid-bass frequencies relative to a solid state amp. It seems to me to be probable that the speaker was designed with the expectation that it would generally be used with solid state amps. If so, using a tube amp with it would mean that its tonal balance would deviate from what the designers intended, and would be a compromise.

I'm not saying that the degree of that compromise would necessarily be objectionable, or that it would necessarily be a bad matchup, but I suspect it would be significantly less than optimal. And that compromise would involve parts of the frequency spectrum that are particularly important.

Regarding v.1 vs. v.3, I know of another member here who uses a much larger and much more expensive Paradigm model, and it has similar impedance characteristics. Which reinforces my expectation that the impedance characteristics of your speakers are similar to what is shown in the graph I linked to.

Regarding the Acurus A100, one factor that may be in play is that its input impedance is only 20K, which may be too low to be optimal for use with the Lightspeed. You might want to ask George about that, either directly or in the Lightspeed thread. The output impedances of your sources will be a factor in that, since with a resistance-based passive attenuator the impedance at the output of the attenuator will depend to some extent on the output impedance of what is driving it (as well as on the volume control setting).

Regarding your question about the rest of your equipment, I see nothing that particularly stands out as a weak link. I'm assuming that you've kept the length of the cable at the output of the Lightspeed short, as it should be.

Regards,
-- Al

Bruce (Bifwynne), yes I was referring to you. Thanks for chiming in and for adding the further specifics. Bruce (B_limo), as the other Bruce indicated he has obtained good results pairing his ARC amp with Paradigm speakers due to the fact that his amp has significantly lower output impedance than most tube amps, in addition to which it is very robustly (and expensively) designed and incorporates large amounts of energy storage.

Czarivey, thanks for chiming in also, and for the best laugh of the day :-)

Best regards,
-- Al