Tube Amp Recommendations $1500


My last amp was a Prima Luna Prologue 5, and it was my first Tube amp, and I loved it! I ended up selling because I turned it on one day and it sparked, then smoked, and as a result, one channel played quieter and distorted. I didn't want to deal with it and needed some cash, so I sold it...

I am currently using a modified Acurus A-100 which is a great amp for the money I spent ($300) but 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.

My current set-up is:
Pangea P.C.'s
Signal cable silver res. interconnects
Lightspeed Attenuator
Parasound Z-Dac
Wadia 170i
Ps Audio Quintet
Paradigm Sig. 2's V.3
4 gik 244's
11x13 room
Musical tastes: Rock, Electronic, female Vocalists, Classical, Jazz.
128x128b_limo
Al could certainly be correct in suggesting your speakers were designed with SS amplifiers as the expected choice for driving them. I've never really heard a SS amp sound like a tube amp if it's truly "tube" sound you're seeking.
Best of Luck.
Charles,
I did reference that Stereophile review that Al posted a link to and those are v.1's, not the v.3's like I have... I don't think there is a huge difference in their specs sensitivity wise but there could be.

Aren't there tube amps in the $1500 range that are stout enough to drive these speakers?

-Bruce
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
Al is right! Paradigm isn't for tube amp. All you will gain is a new $1500 toy and distorted unbalanced and unrealistic sound where Johnny Cash will sing with voice of Madonna.
Not sure if Al is referring to me. I own the Paradigm S8s (v3) and drive them with an ARC Ref 150, which is a tube amp. I suspect the S8s (v3) have pretty wild impedance and phase angle plots based on bench reports of the S8s (v2) that I have seen. Having said that, the S8s (v3) have upgraded woofers and a modified x-over. I surmise the impedance and phase angle plots of the S8s (v3) may be different than the S8s (2), but I am not sure how much so.

Notwithstanding all the techno-babble, based on a telephone conversation with Paradigm tech folks, I was told the S8s (v3) were voiced to be driven by a high current SS amp, which almost by definition has very low output impedance.

As an fyi, I've been able to squeak by because my Ref 150 has an output impedance of .8 ohms off the 8 ohm taps and has a 1040 joule capacitive power supply. As a consequence, it performs somewhat like a "low'ish" output impedance SS amp and can deliver a lot of power in short bursts if needed.

Btw, I believe the link to the Stereophile report relates to the S2 (v1), which is a very different animal than the S2 (v3). Even still, my advice is that you match the S2s (v3) with a very stable high current SS amp.