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Looking for great tube integrated for Martin Logan Summit X speakers

I've had upgrade fever every since I added bass traps and acoustic panels to my listening room and wondered why I didn't do that years ago.  So I've decided to change my Plinius Hautonga integrated and make the plunge to tubes. I want that sound, and the thought of tube rolling appeals to me.  I was leaning toward the Primaluna Dialogue HP integrated, but after doing more reading, I'm concerned that it won't have adequate power due to the Summit's impedance needs.  I'm admittedly a novice with tubes, so seeking help from the forum.   My room is about 12x15, with the area behind my listening position open for an additional eight feet.  I don't listen at high volumes at all, and my favorite music is female jazz, smooth jazz, Nora Jones type vocals.  Music comes from SACDs and Tidal exclusively - I have no analogue gear.

The rest of my gear:
  • Gustard x20u DAC modified by Rick Schultz
  • Oppo 103D for SACDs modified by Rick Schultz
  • Bryston BDP-1 music streamer
Will I be happy with the Primaluna, or do you have other suggestions in the $5,000 range?  Or should I stay away from tubes for these speakers?

Appreciate your opinions!

Steve
smills59
georgehifi's avatar
georgehifi
4,966 posts
 
All you have to do is look at this impedance curve, with a 4ohm load and and negative 65 degrees of - phase angle at 3.5khz you have an amp busting load that would seem to be blow 2ohm!!! EPDR.
Then again at 5khz to 20khz it goes from 2ohm down to 1ohm.
http://www.prespeaker.com/wp-content/uploads/2018/04/martin-logan-summit-x-impedance-phase-graph.gif

No tube amp will get the best from these speakers, unless it has lots of global feedback is over 100watts and has an output transformer specifically designed to be 2ohms.

The best amp to get the very best out of these are solid state and ones that can "almost" double their wattage from 8ohm to 4ohms and then from 4 ohms to 2ohms.

Cheers George
georgehifi's avatar
georgehifi
4,966 posts
 

Forgot to mention, also at 250hz there’s a 4ohm -60 degree phase angle load which will equate to around 2ohms EPDR ( equivalent peak dissipation resistance ), that will also be hard for a tube amp to drive.
This is the power region, which will give good "body" to lower/mids if driven correctly.

Cheers George
captaindidactic
3 posts
 
My advice is that you have to audition them in your own home. I did that just last night. I had my checkbook out prior to the test, fully convinced that I was going to be the proud owner of a PrimaLuna HP integrated amp. Also in the mix was a 400 watt Anthem STR integrated amp. 

Although I loved the stage presence of the PrimaLuna, unbelievably, it didn't have the power to run my hungry AR 910 TSW's. The sound could be phenomenal if I ran mono blocks, but I wasn't ready to shell out that kind of money. 

Next up was the Anthem. It had power in spades, but lacked the depth and warmth. 

I then re-auditioned my 1980's NAD 2600's and to my great surprise that system had the best over all sound. Richer, full and more stage presence than the Anthem, and better bass control than the PrimaLuna. 

The reason for the want to upgrade is that I have a intermittent static somewhere in the system. It has been to the repair place twice and no help. Suggestions??? 
helomech
766 posts
 
@georgehifi brought up some good points. I didn’t bother to look up the real-world efficiency specs of these speakers.

If you want tube sound from a solid-state integrated, look into the newer Yamaha MOSFET-based amps. I’ve yet to encounter any others that come near as close to emulating the lush midrange and 3D-holographic soundstage of a tube amp - not even the tube/SS hybrids. I’ve compared my A-S1100 back-to-back with my CMII, which is fitted with NOS tubes, and the Yamaha manages at least 90% of the tube character, but with greater detail.

These integrateds are 2-ohm stable, run cool (at least, they do with 4-ohm nominal speakers), and have very large power supplies. They’re also dead-quiet in operation. A lightly-used or demo A-S3000 would probably fall within your budget.
smills59 OP
24 posts
 
Thank you for all your comments.  I am definitely a novice here, so please excuse these questions.

My listening position is about 8 feet from the speakers.  I never listen loudly, and I prefer chamber music jazz, blues, Nora Jones, Diana Krall, and similar.  So I definitely don't stress the speakers at all.  Knowing that, should I still be concerned about impedance levels?  The Primaluna has very large transformers.  They also say that Martin Logan used their equipment at shows a few years back.  The Summit X speakers have a sensitivity of  91 dB/2.83 volts/meter.

@georgehifi, that Yamaha looks like it might be a good option.

Thanks!!!
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