Low power tube amp for Sonus Faber?

I have set up a pair of 40 watt single ended tube amplifiers to a pair of the Sonus Faber speakers. The customer was thrilled. I think you will love it.

I use a 45 watt/ch tube amp with my SFGH’s...a superb match. However, the answer to your question involves many variables. The size of your room, the particular tube amp you are going to go with...and it’s ability to drive lower impedance loads, the quality of the particular tube amps transformers, the type of music you play, the loudness that you like...and on and on. IME, Elipsa’s will typically respond well to an amp upstream with some good power...so 30watts/ch might not do it for you, but again...many unknowns and variables.Best answer is to borrow/demo the amp you are considering and see for yourself.

specs on your speakers 91db SPL (2.83 V/1m) 4 ohm load
i am using the mastersound compact 845 on a pair of rosso fiorentino volterra speakers
with specs 87db spl (25.83v/1m)  6 ohm  3 ohm min.
my room is 12"x15"x8"  i get plenty of volume.
the mastersounds have great transformers.

ei001h
Low power tube amp for Sonus Faber?
Mastersound 845 compact for my SF Elipsa SE.
It uses 2 845 Valves, single ended at 30W per Channel

https://www.stereophile.com/images/archivesart/1207SFEfig01.jpg
" the speaker is still a demanding load for the partnering amplifier, with an impedance magnitude that drops to 2.5 ohms throughout the upper bass (fig.1). There is also a punishing combination of 4 ohms magnitude and –50 ° electrical phase angle at 70Hz that will suck gobs of current from the amplifier".


No No and No, from 70hz through to 180hz the bass power region you need an amp with current, at 70hz especially it could be lower than 2ohms EPDR as seen by the amp.

They will work and sound ok, but the bass will be nothing like it could be.

Cheers George

maybe look at the mastersound evolution 845 amp.

 The Sonus Faber Elipsa can sound beguiling with a tube amp. I own a pair of the Elipsa SE and drive them with an Audio Research Ref 110. They need high quality power to sound their best. A 100 wpc tube amp is about the lowest I would go. Without enough power, the bass will not be as crisp and well defined. Also it may impact the soundstage and they may sound a little closed in. The only way to know for sure is to hear the amp in your system. With the right amp and preamp these speakers sound amazing. Good luck!

My options are 845 compact or mc275. 845 evolution is not an option for me. 

I think MS is more high end than mc 275 (is this accurate ?) and I’m trying to stay away from Mcintosh. I’m currently using mc452 and c2600. 

@mboldda1 

how is your low end bass performance? 

@georgehifi 

I’m  not sure how to interpret those numbers. Also have an option to get an older Krell ksa300s, not sure if it’s superior to my Mc452. What do you think ? My plan is to have one SS and one tube for Elipsa. 

@ei001h  Also consider Lyric Audio.

Here is their Ti140 Mk2 integrated...

https://www.thecableco.com/used-components/used-amp/ti140-mk-ii-integrated-amplifier-silver.html

You will have ample power with 70 watts per side when using the KT150s. It allows for negative feedback adjustment and wide tube type (and variant) options.

I found it's performance to be superlative in conjunction with a power conditioner.

A lot will depend on your room size and listening habits.
The speaker efficiency is about 88 or 89 db 1 watt/1 meter; on paper the speaker is rated with the sensitivity spec of 91 db. But because its nominally 4 ohms, this means that the voltage into the speaker will be more than one volt; hence the lower efficiency.
With tubes, the efficiency spec is a lot more useful!!

30 watts won't be a lot of power on this speaker. I would consider something with more power. The low impedance dip in the mid bass is not challenging to most tube amps (including OTLs) so I don't think you have any worries there. I would shoot for an amplifier with 100 watts or so- you could get by with a 60 watt amp, but if you play tunes like I do, you'll be running the amp out of gas.

I have a small room and listen mostly to piano, jazz, opera, classical, full scale symphony etc. 

If I crank up the volume, am I risking amp to clip and damage my elipsa? 

i really wanna get the amp, I’m in love with it. 

I bet that amp will never get out of 2nd gear in a small room even with the SF speakers, and it's doubtful you will ever use up the 30 watts unless you use your room for drunken dance festivals...30 single ended watts is a strong wallop of mojo. I initially used my 12WPC Dennis Had SEP amp with allegedly 91db speakers (they may have actually been closer to 89db based on Stereophile measurements) in a largish room, and the preamp (SS with lots of gain) had enough gain to drive the amp into clipping which I only did when wondering, "what does this amp sound like when clipping?" Music could be plenty loud well below the clipping point so I just enjoyed the crap out of the rig...switched to 99db speakers eventually (Klipsch Heresy III) which really are more appropriate for this amp, and use a lower output tube preamp. Now things can get way louder than I ever want it to with absolute clarity, well under the clipping zone.

Hi ei1001h,
I can understand your fondness for the Mastersound 845 as they can sound simply gorgeous with the ’right’ speaker match. You’ve received some good replies.
1. George makes a compelling point in regard to the load demands of your speakers in the difficult mid bass region.

2. I find it interesting that atmasphere doesn’t consider this to be a challenging issue (mid bass load ).

3. Mr. Garcia makes a keen observation that in a small room the 30 watt SET amplifier won’t be a limiting factor (he may be right given the circumstances ).

Is there any possibly to hear the Mastersound in your system prior to purchase? Obviously this would settle the issue.
Best of luck,
Charles

If I crank up the volume, am I risking amp to clip and damage my elipsa?

No.

i really wanna get the amp, I’m in love with it.

 Imagine putting monster truck tires on a British sports car from the 1950s- if you really want to experience the charm of such a vehicle, put appropriate tires on it. Same thing here- if the amp is the determining aspect, get a set of speakers that will do it justice. A more efficient speaker and maybe one with higher impedance as well will really help.

ei001h OP
I’m not sure how to interpret those numbers. Also have an option to get an older Krell ksa300s, not sure if it’s superior to my Mc452. What do you think ? My plan is to have one SS and one tube for Elipsa.

I’ve never been a fan of solid state amps with "autoformers" like the MacIntosh has, band-aid fix for amps that can’t do the job without the autoformer.

Sadly "if" the Elipsa had bi-amp speaker terminals having the SE845 on the mids and highs (250hz up) and the Krell on the bass (250hz down) would have been the way to go, with a passive volume control on the louder one to match the levels, but sadly they don’t have bi-amp speaker terminals.

And I not a biggest fan of the KSA300s bass is great, but they lost some of the magic in the mids and highs when they went with that 1st generation plateau biasing for some reason with the "s" models.

Out of all those four amps you have, and you can’t bi-amp. It’s the Mac or the Krell, my bet is on the Krell.

Or cull all 4 amps you have and get one magic one like the Gryphon Antillion Evo 3 or 4 user switchable Class-A bias on the front panel even while musics playing, my friend has one of these on his Wilson Alexia’s, it’s a game over for amp searching, it does everything, the bass of the biggest Krells and the ease and euphonic’s of the SE845’s.

There is another amp at a reasonable price, and that's the new JC5 Halo it was bought out as an answer to potential buyer not being able to afford the JC1 monoblocks, John Curl as you may know is one of the gods of advancement amp design like Nelson Pass, they don't rest and reconfigure what was around in the old days but rather advance designs with new and advancing technologies, neither though have embraced Class-D.   

Cheers George

Hello ei,

I am the US distributor for MastersounD.  If you would like to talk more about options with your speakers, please feel free to reach out to me.  There are many things that would need to be discussed to make sure you get into the right amp for your needs.  

Cheers,

Skip

ei001h OP

Also if your interested ei001h here is an A/B of the JC5 vs the $8.5K McIntosh MC452
  
"Tonally, the MC452 and JC 5 are nearly opposites. The MC452 is more organically textured and warmblooded. It has a denser and more colorful tone. The JC 5 is superior in its instrumentation and vocal outlines and has more dimension and air. The MC452 has less depth and is fuzzier in comparison but has more contrast with its texture. The MC452 has a more forward midrange with very nice weight and slam. The JC 5 is much quicker, more insightful, has tighter bass, and breathes further into the room. It has a wider and deeper soundstage while the MC452 is cozier. Cymbals have more zing and splash with the JC 5 while the MC452 isn’t as vibrant. The JC 5 also does a better job layering out the soundstage and separating out the performers."

And this is on B&W 804D2 quite a bit easier to drive than you SF’s, on them the differences would be even greater, especially in the bass where the JC5 would be in far less coloured and in great control with more impact and drive.


Cheers George

I use the exact same speakers with a 34 wpc EL-34 PrimaLuna DiaLogue One with great results (I also use KT-88's in the PrimaLuna from time to time). I currently switch between the PrimaLuna and a McIntosh MA8900 integrated (solid state, 200 wpc). For what it's worth, the difference is *not* night and day as you may think. In fact, sometimes the tube integrated sounds more "powerful", and vice-versa. Sometimes, the McIntopsh sounds warmer and more "tube-like". So, it's all about synergy, your room, your personal tastes, etc. I say give it a shot!

Call Upscale Audio and talk to Kevin Deal as I think they sell Sonus Faber and tube amps. 

"Would really like to try a valve amp on the Elipsa. Is this a mistake?"

Why ask the question if you're not willing to accept the answer?

I borrowed a Cronus Magnum 2 from Rogue Audio and hooked it up to Sonus Faber Venere 2.5. I didn't like it as much as the solid state Arcam amp I have been and still are using. The clarity of the high and mid-range music was less and the bass power and clarity less with the tube amp. The Sonus Fabers are such a rich, warm speaker I'm not sure that they benefit from the overtones of a tube amp, at least mine, in my room did not. So, I didn't spend the money, and am using this old amp which truthfully makes these speakers sound better than anything I ever thought I would be able to afford to have in my house.

Thanks everyone for input. It seems the majority here agrees 30w is not ideal. So if that’s the case I might be able to get mastersound 845 evolution. It’s 55w per channel. Would this be better or I shouldn’t bother at all under 100w? 

The problem is that you can’t just go with arbitrary power/watt numbers to decide, it isn’t that simple. Two amplifiers can have identical watts and yet be in some cases vastly different in performance and drive capability. This is what Garcia was alluding to in an earlier post.

I’d strongly suspect the 55 watt Mastersound has beefier transformers and power supply which would be an advantage. In your smaller room environment and listening levels and preferred music fare it’s possible the 30 watt amplifier could be quite adequate. It just depends on the variables involved. I’ll ask again, is there the opportunity for a home audition?

If the 55 watt Mastersound is within your budget certainly it’d be the safer choice. 
Charles

The Sonus Fabers are such a rich, warm speaker I’m not sure that they benefit from the overtones of a tube amp, at least mine, in my room did not.

So is this why the company that owns Sonus Faber also owns Audio Research and MacIntosh?

It seems the majority here agrees 30w is not ideal. So if that’s the case I might be able to get mastersound 845 evolution. It’s 55w per channel. Would this be better or I shouldn’t bother at all under 100w?

That’s not quite double the power- not quite 3 db,,, 100 watts would suit better. But here’s the thing about tube amplifier power- its always been expensive, and for that reason speakers with higher efficiency are recommended. The thing is, you don’t have to take a loss of either resolution or bandwidth in having a more efficient speaker! My speakers are 98 db, 16 ohms and go to 20Hz on the bottom and yet they are also one of the most resolving and natural sounding speakers I’ve heard.


IOW if you really are smitten with the Mastersound, get more efficient speakers.

According to a lengthy email exchange I had with Roger Sanders --over 40 yrs of ESL experience -- the jist of what he explained to me is that speakers with a 4 ohm rating will not actually perform at their state SPL range.    a 91 db rated speaker will be somewhere in the 80's.     The discussion I had revolved around a pair of Decware speakers rated at 94db..   Roger's calculation indicated that they were more like 86 db or something to that effect.   If Im not mistaken has to do also with not being 1 watt @ 1 meter.   Im sure someone here that posted remembers better than I.  

wolf

tell me more about these " drunken dance festivals "..... also a location would be helpful................and some dates......and times.......

According to a lengthy email exchange I had with Roger Sanders --over 40 yrs of ESL experience -- the jist of what he explained to me is that speakers with a 4 ohm rating will not actually perform at their state SPL range.   a 91 db rated speaker will be somewhere in the 80's.

Yes. 91 db and 4 ohms will be 3 db less, or 88 db. I mentioned this earlier:

The speaker efficiency is about 88 or 89 db 1 watt/1 meter; on paper the speaker is rated with the sensitivity spec of 91 db. But because its nominally 4 ohms, this means that the voltage into the speaker will be more than one volt; hence the lower efficiency.With tubes, the efficiency spec is a lot more useful!!

The Evolution 845 is the amplifier I was hoping to suggest and it looks like it is already on your radar.  The Compact 845 is an excellent amplifier, but might not be right for every situation.  In this case, I do think the Evolution 845 would be the top contender.  The price is much higher, but so is the performance.

Like Charles has hinted at, the transformers are massively beefed up in the Evolution 845, bringing the weight up from 75 lbs to 117 lbs.  I have had a few speakers in house where the Compact 845 was just not the right bill and for every one of those speakers, the Evolution 845 lit them up.  

The Evolution 845 is a statement piece that I have yet to find a poor match with.  I'm not saying they aren't out there, but they haven't presented themselves yet.  Even on Martin Logans, the amp has performed magnificently.

Audiothesis,
Thanks for the additional amplifier information, it confirms what I suspected. All design and built parameters of a power amplifier have to be considered. 50 watt amps of the caliber of this Mastersound Evolution can manage speaker loads that some higher wattage amplifiers can druggie with. Just saying that ’X’ amount of power is sufficient doesn’t account for the entire picture/scenario.

I recall a situation described by an Audiogon member Raquel ( former TAS reviewer I believe ) several years ago. At a demonstration a 750 watt VTL was having a very tough time driving a pair of speakers. They replaced the big VTL with a VAC Renaissance 70/70 (65 watt) amplifier that easily drove the same speakers. Obviously this suggests very different design aspects of the two tube amplifiers.

The VTL wasn’t a bad amplifier by any stretch, just a poor match with these speakers despite the very high rated power. Power supply and transformer quality are crucial considerations in the big picture with regard to tube amplifiers.
Charles

Just found this review by Jeff from Tone Audio: 

"With a wide range of amplifiers at my disposal—solid-state, tube and class D amps, ranging from a pair of 20-watt 845 SET monoblocks all the way up to the mighty Pass Labs’ XA200.5 monoblocks—all were able to drive the Elipsa SEs without difficulty. Granted, each amplifier imposed its own sonic personality on the presentation, which complements the high resolution that these speakers offer. But still, every variation on the theme remained thoroughly enjoyable.

Thanks to a sensitivity of 91 db per watt, the Elipsa SE is comfortable with the 35 watts per channel that the average EL34-based tube amplifier can provide, but because the speakers have a maximum power handling of 300 watts, they will absolutely crank if you have enough high-quality power on tap"

I know that you have to double the power to get 3db increase in sound, and evolution 845 55W isn't quite double that of compact 30W power. But something tells me it isn't all that simple, and more power will still sound better overall, even if I don't push the amp to its maximum.