Tube Amp Recommendations $1500

Will Vincent's Dynaco Mk IIIs are awfully nice. A pair comes in at about $1400 if memory serves. He goes by autospec here on the board.

05-28-14: Almarg
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,

No problem Almarg with B limo using the Lightspeed with this setup as his Parasound Z dac has a low 160ohm ouput impedance, which can easily drive the combined Lightspeed and Acurus load of 6.6kohm.
As always use up to 2mts interconnects of low capacitance less than <100pf (picofarad) per foot, which most quality ones are anyway, from Lightspeed to poweramp/s.
If higher capacitance 200pf per foot then 1mt should be used.

Cheers George

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

Thanks Al, Czarivey, and Bifwynne, I'll take your advice and stick with solid state for these speakers.

I'm glad I asked now.

Thanks to everyone else that replied too!

The SQ-88 from Quest for Sound. Brand new right at your price point. Solid build and great sound. Comes with remote volume control as well. Check other audio website usaudiomart.com for used. Really a fine tube integrated with great reviews.

CJ & LM, just about any, will sound better than Prima Luna and much better than old Acurus. I've owned at least 4 different Acurus products (amps and integrateds) and had to finally accept that while powerful and well built, sound was dark & brittle (non "a") to bright and brittle ("a" series). CJ (tube or ss) or LM will sound much more musical. Don't discount LM as integrated. I've never been happy with passive preamps - too lean. Either an LM integrated or even the new Rogue Audio Sphinx hybrid integrated would work great - and the sphinx should have no problem with your paradigms and only $1300 new. That's probably the easiest most reliable way to have some tube goodness without the hassles.

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.

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.

Quicksilver Silver 90 Monos are still fantastic sounding amps, competing with those many thousands more. At 90wpc, they have great bass control.

Check out JWN Amplifiers and reviews by renowned reviewers Lynn Olsen at Positive Feedback and Dick Olsher. Each amp is hand-built and competes with amplifiers way above your budget, but can be easily be built well within your budget. Jim is a great guy and easy to work with and will build you an amp to your specifications. I can personally attest to the quality and sound. The reviews speak to the quality and performance. BTW, I also have a passive preamp that I switch out from time to time. Your lightspeed should be a great match Good Luck!

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

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

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,

Thanks so much guys!

I will look into these tube amps mentioned. I'm sure there are some good recommendations in there.

Al, I do believe that stereophile review was of my speakers (Sig 2 V.3's); I look into that further to confirm. I wondered how these would pair with tubes but I thought the Prima Luna Prologue 5 pushed a variety of speakers well (jamo d830, quad 22l2, joseph audio rm7si and 25si) but maybe I was wrong...

This may have opened a whole new can of worms because I really like these speakers. I thought I could gain a little more extension in the highs, more of that organic life like sound I was experiencing with tubes, while keeping the more controlled bass of a solid state and gaining more headroom and higher volume than my current Acurus A100.

Maybe I should be looking at high power solid state amps that have a "tube like"' sound? CJ? McCormack? ...?

And since I have your attention, I'm open to criticism on my rig. Do you see other weak links or areas to possibly change? Thanks!

Hi Al,
Good points you raised. The Line Magnetic amplifiers generally speaking have rather stout output transformers and power supplies. They are reputed to drive loads better than their watt specifications would suggest.
Charles,

Indeed it is the 216 I was thinking of. I believe it's around 40WPC. I am not familiar with the power output of the Prima Luna, so the OP will have to decide on how much power he needs for his speaker. I have no experience w/ the Paradigm. Cheers -Don

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

Audio Research Classic 60
conrad johnson MV75A-1
conrad johnson MV55

Quicksilver mid-mono, few hundred dollars more than your budget but worth every penny.

+1 the Line magnetic amplifiers, I think they're worth serious consideration.
Charles,

LM Audio 211 or 219. The former uses EL34, the latter KT88!

That's too bad about your PrimaLuna. Are you now turned off on owning another one? Reading your posts made me start to consider a PrimaLuna.