Best Tube Amp For Sonus Faber? Or Pass XA-100.5? $6-7,500 Budget, Purchasing Used.

The new IQ continuous auto bias in the latest VAC amps are a night and day difference from their prior 160, 200, 300 phi models.  Far more smoother and transparent, tighter bass, etc and more stable power output makes it a lot easier to handle all speakers.  I owned the VAC and as well as the SF Olympicas and the Elipsa and handled them fine.  the VACs are paired with Magicos, Focals, Vandersteens, Sonus Fabers, Harbeths, and know they can drive them well, even with the stock KT88s.   But if you're in love with the PASS LABS, then you it seems like you found what the sound you're after.

I have an Audio Research VM-220 that I just got checked out and put new 6550 tubes (from AR!) that I will be listing shortly.  These monos powered my Sonus wonderfully, but with 12 tubes in each, the room can get warm.  Great sound though. - PM me if interested.

I should perhaps have mentioned that a big part of originally wanting the 100.5's had to do with how impressed I was after hearing the 60.5's (not enough power for my speakers) and recalling John Atkinson's review a couple years back calling those the best amplifiers he had ever heard. As a followup, I was told that the 100.5's were essentially the 60.5's up-scaled, which doesn't seem to be the case?

All Pass amps seem to have a slightly different sonic signature. From what I understand, the XA160.5 is the next logical step up in power and flavor from the XA60.5. I've had many Pass amps, and while the highs and mids were wonderful on XA100.5, the bass seemed bloated to me. Some say it the most tube-like of the amps but, to me, not in a good way. The XA60.5 were amazing sounding amps (I love the XA60.8 and X350.8 as well). I love Pass, if you can handle the heat. My favorite right now is the X350.8. Several friends have them and I always look forward to going to see them and listen to their systems.  

djfst said:

" The new IQ continuous auto bias in the latest VAC amps are a night and day difference from their prior 160, 200, 300 phi models.  Far more smoother and transparent, tighter bass, etc and more stable power output makes it a lot easier to handle all speakers.  I owned the VAC and as well as the SF Olympicas and the Elipsa and handled them fine.  the VACs are paired with Magicos, Focals, Vandersteens, Sonus Fabers, Harbeths, and know they can drive them well, even with the stock KT88s.   But if you're in love with the PASS LABS, then you it seems like you found what the sound you're after."

The problem I'm having in moving to a Pass is size and heat. That and the fact that as joeinid noted above, the next amp up the line that shares the true greatness of the 60.5's that I like so much are the 160.5's. Those are not only huge, but can each double as a furnace, in my room, I could sell space as a sauna. Not to mention they are thousands out of my budget. 

I was considering the highly rate Pass 350.8, and one was just available at a price several thousand under the going rate, and in my budget, but it sold before I could make a final decision.

So I was strongly leaning back toward the VAC and even talked to them at length. I know the PHI 300.1 will handle my speakers perfectlY, and there is one available, but it's not the latest series which you've noted represent a "night and day difference". And the newer model PHI 300.1a, on the very rare occasion it is available for sale, used, runs in the $10k area and also out of my budget. 

Those situations currently have me in a position where there isn't a clear choice unless I go with the PHI 300.1 available at the moment, which, both you, and an audiophile friend from Chicago have advised me is decidedly lower in sound quality than the newer version. 

This decision is not easy for sure.  There is a newer version 200 IQ on US Audiomart.  It is just a little bit more than the phi 300, but maybe talk with the seller.  The other great thing about the VAC is tube rolling.  With the auto bias, changing out the driver tubes (the 4 6SN7) can tailor your sound to your liking.  Unfortunately, whatever you have with the PASS Labs is fixed in stone.    No doubt the VAC will handle the Olympicas with ease.    I must confess, I am a tube guy and not a huge fan of solid state.  So I am biased :)  The VAC is best blend of solid state and tube sound I've come across (at least the newer models).   

I'm a tube guy too, and so, share your thoughts on this. When I talked to VAC, they were pretty clear that they thought even the older PHI 300.1 would outperform the standard 200IQ. Which it should, granted that the list on the PHI 300.1i, when last available a few years back was $20k, vs $14k for the 200IQ. And the PHI 300 are the top series, in terms of performance. They also had some concerns that the 200IQ stereo version would not prove sufficient to optimally drive my speakers fully. 100wpc is somewhat marginal. I also can't bear to have tubes locked up in a box, I need to see them! Not sure why they went that way with the 200IQ's.

They did say the the Signature 200 IQ Monoblocks would certainly better the PHI 300.1, and also drive my speakers to perfection, but those are $28k new and, even used, would not come near a price I could afford.  

that's surprising to hear, considering the 200iq is much newer than the phi 300 and has more of the flagship statement series technology and engineering built in to the 200 iq.  I talked with Kevin over the phone and he stated the 200 should drive the Sonus Faber line fine.  not sure if you spoke with him.  

the aesthetics of the iq (with the tubes in the back) represent a similar model they did before - I forget which one it was, but I know they used that design on the VAC Alpha Phi Integrated.  Personal preference, I guess.  Keep us posted on your decisions.  Not an easy decision for sure.

nightfall,

you may also want to reread this thread from a VAC dealer in florida, though it is just another man's opinion, which everyone has a different one:

http://www.audioshark.org/vac-85/vac-signature-iq200-9738.html

djfst,

Thanks VERY much for your continuing help and information. I actually talked to Brent, as Kevin wasn't available, but I understand it, he is Kevin's right hand man. and he was incredibly helpful and knowledgeable. We discussed a lot if things, but I "believe" it was the current model PHI 300.1a which, and again, IF I understood him correctly, would still outperform the 200IQ. And again, that makes rational sense as I have trouble imagining that they are selling a $14k amp that outperforms a $20k amp in their current lineup? But I need to validate that I have all these facts right and will talk to VAC again on Monday. I will report back here and qualify too.

I know that any other amp I am aware of with 100wpc would not be a match I would trust with the load of the Olympica III's, given it's overall difficulty to drive, and it's drops to 2 ohms. Granted I am likely a bit oversensitive on that topic, since I've just had to resell an amp at a loss, that I truly wanted, and had just purchased two weeks ago, but which could not drive the speakers. That despite a major review telling me I would have no issue. 

I will very specifically revisit that when I talk to them on Monday. 

Lastly, thanks for that link. Clearly great minds think alike, as I only just finished reading that entire discussion after looking for more info on the 200IQ's earlier. It's very impressive commentary, though, granted, they are talking about using a pair of the amps as monoblocks. 

djfst,

Quite a bit earlier in this discussion you said "  Would not go with the VAC Phi 300.1.   Definitely go with the updated VAC Signature 200 IQ with continuous auto bias.  100+ watts and has all the bass and tightness of solid state and the midrange is fantastic.    Retails for $14k but there is a like new one listed on US Audiomart.  With the auto bias of the 200 IQ, you can plug in any KT88, KT120 or KT150 and change out the 6sn7 driver tubes if you want to tailor the sound.  It is so user friendly and the stock tubes are wonderful though.  Have owned both the Sonus Faber Olympica III and the Elipsa SE.  The VAC controls the bass of the olympica which can often sound a little bloated if not having a high quality amp."

Which VAC amp were you referencing as handling the Olympica III and Elipsa so well? I originally thought you were referring to a previous amplifier, not the Signature 200IQ. If it was the Signature 200IQ stereo version, that would carry a lot of weight towards my decision. 

Sorry for the confusion - It is the stereo Signature 200 iQ that I used with the Sonus Fabers and I felt it handled them with ease.  I moved from a Primaluna HP amp and the 200iq was a significant jump.  Everything came into focus and the bass improved significantly.  

That now makes sense about the current version 300.1a  beating the lower priced 200iq.  I thought you were referring to the older 300 model that is listed on audiogon.   It would seem strange that Kevin and Brent would give different information, but Kevin told me the power output of the 200iq would hand the Olympicas fine.   It may also have to do with the quality of the wattage.  The VACs put out a lot of power, but it is quality continuos power - Kevin gets a lot out of his amps.  Happy to help and keep me posted.  I understand being burned before on your prior purchase - I feel for you.   Kevin is one of the most honest and nicest guys in the business and can't believe he will steer you wrong.

Also - I always use the 8 ohm taps for the Sonus Fabers (both the Olympicas and Elipsa), though they are rated at 4ohms.  Definitely performed best on the 8 ohm taps for both the Primaluna and VAC amp.

Did you ever look at the impedance curve for the Olympica III?  Here is the link:  http://www.soundstagenetwork.com/index.php?option=com_content&view=article&id=1285:nrc-measu...

They only dip into the 2ohm territory very briefly and stay at or above 4 ohms most of the time.   At 91db,  I didn't think they were extremely challenging to drive well, compared to some other SF models like the Amati Futura and other homage models as well as other manufacturers speakers.  

Thanks for the tip on the 8 ohm taps. I would not have expected that. Another reason why it's good to experiment on what might work best. By the way, what preamp were you using with the Olympica III's and the 200IQ?

Very eager to call VAC tomorrow to get clarification, and answers to some key questions. After that, I think I will know where I stand, and what to do. 

They only dip into the 2ohm territory very briefly 

Yeah but it spans between 70hz and 150hz right in the power region for bass, and you'll get a big dip in power there if the amp can't give the current into it. especially from an 8ohm tap.
This is a more telling graph.
https://ibb.co/hoYNyF

Cheers George

They only dip into the 2ohm territory very briefly

Yeah but this dip spans between 70hz to 150hz, the power region for bass, if the amp can't deliver current into it, you'll get a big dip in power in that region, especially from an 8ohm tap.
https://ibb.co/hoYNyF

Cheers George  

I too have the Sonus Faber Olympica-3 Loudspeakers.
I was using a dual mono 50wpc 4ohms pass labs 
And had 100 watt AR  tube amp softens the leading edge these speakers like current dual woofers give excellent bass yo around 30 Hz. 
But only if you give them power .I  tried my friends Ampzillo mono blocks 
Very good vs pass or anyone these to for over $10k
And will go to to toe with amps $$$.
Underwood wally has these on special. Don't take my word for it .
Read the reviews. I just bought the smaller but Very capable son of Ampzilla MK-2
350wpc into 4ohms  .on d of the guys st our sudio group has one and Very close yo the mono in every way  never need more power.

The 8ohm taps were clearly better, and had a hard time understanding why based on the impedance graph.   There is another audiogon forum discussing this where someone else mentions the Olympica III runs better on 8ohm taps for them too.   It was interesting, because the Primaluna taps were, 4, 8, 16.    But the VAC 200 iQ (and probably other VACs) have ranges for their ohm taps:  1-2, 2-4, 4-8.   This may explain better why the VAC runs the Sonus Fabers better, since there is a broad range where the ohms are constantly changing.  Maybe the VAC is better at handling this?   Not sure.   All I know if the 4-8 ohm taps (and the 8 on the Primaluna) were clearly better.   Judge by your ears in the final analysis.

Nightfall, the Preamp I have been saving for.  Initially was the Primaluna preamp, but would eventually love to upgrade to one of the following (again a tube guy):  Zesto Leto, EAR Yoshino 868 or 912, Herron Audio, or VAC.   I think VAC is coming out with a more affordable preamp this year.... at least that was the rumor a while ago.  

georgehifi,

I noticed the bass improvement the most when going from the primaluna to the VAC.  that would coincide with what you were saying.  The best bass on a tube amp I've heard was with the VAC.

Nightfall,

Remember that the Olympica III is moderately efficient at 90+db.  so even if it dips low with the ohms briefly, there is more at play with how well an amp can drive speakers.  The VAC dealer on the audio shark forum commented that the 100 watt specs for the 200 iQ was very conservative, and is likely much more power that is giving out.  I've noticed that in my experience with it as well.

djfst,

My current preamplifier is the top of the line PrimaLuna Dialogue Premium, which I have loaded up with very good NOS tubes. I find it to be a giant killer under $10k (granted I stole that line from Kevin Deal who may be  a bit biased, but the reviews support it). 

My list of dream preamps would include the Joule Electra LA-300ME and LA-150-SE, the Conrad Johnson ART 2, the Zesto, and something from VAC. 

I've read great things about the Herron, but have never auditioned one or otherwise had experience with that preamp. What can you tell me about it?

You may be right about the Primaluna - I haven't used NOS tubes yet, so it may be all you need with whatever reference amp you end up with.  I've told by many that the the preamp selection will influence the sound a lot...  The Herron was recommended to me numerous times by a trusted dealer who I value his opinion.  He has never steered me wrong in the past.  Unfortunately, his store is a plane ride away and haven't been able to demo it yet.   I also tend to like to buy things made in the USA - to support local manufacturers and in case of a problem with the unit down the road, they are a simple phone call away.   That can't be underestimated, especially when you are talking about shipping a 100+ amp around the country vs across the world.  VAC, Zesto, Herron, VPI, etc.  are all companies I'd be happy to own and support.   Sonus Faber was the exception :)

nightfall said...
"My current preamplifier is the top of the line PrimaLuna Dialogue Premium, which I have loaded up with very good NOS tubes. I find it to be a giant killer under $10k"

I concur. What NOS tubes are you running?

djfst
georgehifi,

I noticed the bass improvement the most when going from the primaluna to the VAC.  that would coincide with what you were saying.  The best bass on a tube amp I've heard was with the VAC.

It could be the the VAC has a lower output impedance because of two things either it's transformer has a lower impedance winding or the it has a lot more global feedback than the PL creating a lower impedance.

Cheers George 

djfst,

Are you a member on any audio forum where I could PM you, I have made a decision after a long call with VAC today. Some of what was said is not information I feel it right to share here, as it was a private, and extremely upfront conversation. 

For everyone else, I'll report back here with what choice I made, assuming my offer is accepted, etc. 

06-19-2017 3:32pmnightfall said...
"My current preamplifier is the top of the line PrimaLuna Dialogue Premium, which I have loaded up with very good NOS tubes. I find it to be a giant killer under $10k"


aolmrd1241 said
I concur. What NOS tubes are you running?

These for the 5AR4’s:

https://www.upscaleaudio.com/collections/vacuum-tubes/products/philips-5r4gys-made-in-holland

CBS 5814A for the two critical positions, RCA NOS, 1950’s for the four other 12au7’s.

Are you a member on any audio forum where I could PM you

You can PM members on Audiogon.

jmcgrogan2 said:06-19-2017 8:09pm

Are you a member on any audio forum where I could PM you

You can PM members on Audiogon.

If I had known that, I would have PM'ed you previously! Now if I could just find the way to do that.

I discovered how you can PM here. Thanks. PM's sent.

To everyone else, thanks for all of your valuable and insightful information, it has all been helpful in my arriving at a final decision on what is an extremely important purchase for me.

In the end, due to its far newer design, Sentry circuit, Continuous Automatic Bias Adjustment, overall reliability, and it VAC heritage of sound, I have made an offer, and will be purchasing a VAC Signature 200IQ. 

Sonus Faber matches very well with Goldmund amplifiers. Goldmund is fast, clean and wideband. That should give you the idea of what kind of amps to look for. Pass XA is smooth, warm and relaxed  sound. Try to hunt for any of the older model Goldmund. It is a super match.

Enjoy your system upgrade, nightfall!

I owned the XA60.5, 30.5 and the 100.5 as well. The 100.5 where a lot better in all parts compared to the 60.5.

We are not talking only about more power adn control. The stage is wider and deeper. But the sound is a lot more involving and realistisc sounding.

I also was impressed about the 30.5. The 60.5 did not convince me at all for their price.

People often forget what diversity in sound is and what it does. In this part Pass Labs is in a league of its own.

Audio Research has more what I call a sound. This means an involving sound. With less diversity in sound in the whole frequency range.

It sounds like the low, mid and high frequency sound more the same. Diversity in sound is the most important part to feel emotion of the music.

Because the emotion is inside the music. Diversity in sound will create more layers and emotion during listening.

abrew19,

I was told by people involved with the company that the 60.5's would not be a good match due to the requirements of my Sonus Faber Olympica III's. They are 4 ohms, are rated at 90DB sensitivity (which I think is definitely inflated) and drop down to 2 ohms at times. I tried a very good pair of tube monoblocks capable of 65 wpc and they were not sufficient. 

If the 60.5's seem likely to power your speakers, I would re-read the Stereophile review of them, where John Atkinson called them the finest amps he has ever auditioned. 

I have been to Houston a number of times for work, and I would be concerned about the heat output of the 100.5's too!

JC

If the 60.5’s seem likely to power your speakers, I would re-read the Stereophile review of them, where John Atkinson called them the finest amps he has ever auditioned.

There are very, very few reviewers whose opinions I respect, and JA is definitely NOT one of them.
Frankly, I don’t think JA can hear at all. I learned to ignore any comment from him decades ago.

That’s not a swipe at the XA-60.5’s, I’m sure they work fine with the right speakers.

The ARC Ref 5 preamp is not a great combo with any Pass labs poweramp. We auditioned it with different Pass poweramps.

The limitation is based on the fact that stage depth and width is not like other pre amps are able to create.  It makes the stage less deep and wide. But also in speed and timing it is not at a reference level. Beside this the level in details is also limited. We could proof both in details in the high frequencies and even in the layering in the middle frequencies that they ARC Ref 5 was not able to show the these information we could create.

Both XP-20 ( which I owned for 2 years) and the ARC Ref 5 preamp are also limited in individual focus of instruments and voices. 

This means that they are both not able to create an intimate and physical image of voices and instruments.

I had different conversations with Desmond Harrington about the lack of individual focus of voices and instruments.

You need to understand how voices and instruments are being projected into space and how big they are.

I created Statement Audio Pro measurement what brings any Pass Labs poweramp to a superior and new level.

It creates a superior level in details but also in diversity in sound. There are so much more layers compared to the XP-20 and ARC Ref5.

I can create an even higher level about 6 times each year. We are at a level now that the energy of instruments can be felt separately. And even the energy of instruments can stand in a different perspective of depth.

The acoustics limits the quality of a poweramp so much. Without roomcorrection it is not possible to create this stunning level we can achieve at this moment.

We also can play a lot louder in pure class A with Pass labs X-series amps compared to the XP-20.

Now we have ideas to use conservatorium students to explain people what diversity in sound means and does with our emotion. We want to use instruments and real voices to show people how small and direct they are in real.

We can proof now that with Statement Audio Pro music comes so much closer to how music sounds in real. We are born perfectionists and we want to create the best level in realism possible.

I can create an even higher level about 6 times each year. We are at a level now that the energy of instruments can be felt separately. And even the energy of instruments can stand in a different perspective of depth.

@nightfall , sorry JC, once bo stumbles onto your thread, it is destroyed with mind-numbing audio mumble jumble.
It is akin to termites stumbling onto your home.

Did you get your VAC amp yet?
Which model did you buy?
What do you think?

nightfall, 
Pass XA-100.5 would be a great option. Also consider some McIntosh SS amps or integrateds such as the MA7900, MA8900, MA6700 integrateds or the MC350 stereo power amp. McIntosh and Sonus Faber have good sonic synergy together.
I've heard your speakers driven by one of these McIntosh amps before at the store and IMO they sounded great together. 
AR amps would be another good option for your speakers. 

I also heard your your speakers driven by the Musical Fidelity Nu-Vista 600 integrated amp before and I thought they were paired very well together. 
Speaker cables also need to taken into consideration in getting a perfect match with your equipments. 

Some Lamm and higher end Primaluna would be a good option for your speakers.

A tube creates distortion, what it does it gives the whole frequency range a colouration.

The emotion of music is inside the music, not inside any audio system or even tube. So you need to understand first how humans experience the emotion of music.

When you only focus on the most important part of our emotion and also music ’DIVERSITY’ it becomes clear that layering in the whole frequency range is by far the most important part to feel the emotion of music.

This means when a system is able to create a higher level in diversity this system will create more emotion during listening. A tube does not create more diversity. It creates a pleasant sound many people like.

Many people in audio have no idea how limited the level they are able to reach of each single part in an audio system. They created their audio system by trial and error and believe that they created their system by personal preference.

But when you have no idea why the stage and sound is what you hear, your system has been created by trial and error. This is nothing more than audio gambling.

Your audio system is being created by all the different properties of each single part in your system togheter including the acoustics.

The acoustics are the biggest part what influences your sound and stage. That is why I did most research in this part. People have no idea how much details and information gets lost.

People think and work like it was 1980 in audio. Mann wake up, it is 2017. You need to learn to look further to create a superior realistic level in sound.

When you want to understand why the stage and sound is what you hear you need to be able te know all the different properties of each single part in your system.

But........even that is not the whole part.

Smog, high frequency noise, magnetism and even more influences the sound and stage negative.

That is why you only can use a very small level in quality of each single part of your audio system. The level in accuracy is very limited. Buying more expensive audio part will not solve these problems. Even buying tubes will not solve this.

You need to understand where and how you loose the diversity in sound.

When I visit an audioshop, new client, distributer or show it feels like I go back in time 20 years ago. And I hear and see often that they still do audio the same way as when I started to work in audio.

It is difficult to believe and understand how less audio is grown in these 20 years. It is as people have been sleeping all the time.

When you want to able to controle audio and sound you need to learn to understand how it is being build. And first of all you need to understand how voices and instruments sound and how they are being projected into space.

But when I visit new clients, audioshops, distributers and audioshows the facts proof that their systems sound so much different than how voices and instruments sounds in real.

This is based on the fact that all these systems are being created by trial and error. And not even one single person can tell what the different properties are of each single part in thier system.

I asked to all these people: do you understand why the stage and sound is what we hear? No one could answer it. It proofs that the systems are being created by audio gamling.

Beside the fact that the systems are being created by trial and error, it also proofs for me very easily that all the systems are incomplete.

This means that all the systems are missing essential parts on which sound is being build. Each single part influences our emotion.

So all the systems have a lower level in emotion and realism. People need to start to focus on music again.

Many audio systems have been created by thoughts of people and endresults of trial and error. But at the end it has nothing to do with how music should sound.

Without music there is no audio. But.....without audio there is still music.

Where does all your knowledge come from dude? You are simply amazing.

"I had too much to dream last night, too much to dream"

Great thread otherwise, I really have enjoyed the varying comments.

bo1972,

Please post one (1) of your Tru-Fi systems and Room.

 Some of us would like to see and hear the Proof.

bo1972,

PM me.

bo1972

Audigon does not want me to use brands anymore.

That's nonsense. Brands are mentioned here all the time - good, bad and indifferent.

Several posts re the Oly's 3 by SF

just some personal observations as an owner of these extraordinary loudspeakers: first of all, IMHO, they are not compressed, veiled, slow, dull, small, or 'blah' sounding speakers, they are everything but that.  That said, are they are as 'good' as the upper level SF offerings?  I have no idea ! Not going there, as I have no present desire to do so. When I first bought and listened to mine I was not initially floored.  My reference was a pair of bigger speakers with larger woofers, much heavier and more efficient but great speakers nonetheless.   The Oly 3's required some adjustment on my part.  Great WAF and as speakers weighing only about 100 lbs each I could handle them fairly easily vs wresting 200 lb speaks. The fit and finish is world class.  The changes I made upstream made all the difference in the world which allowed the 3's to really shine.  I added  a 2nd external power supply to my First Sound dual mono tubed pre amp. Added an external power  supply to my tubed phono pre amp.  Bought a Pass X250.8 ss stereo amp. You can't make chicken soup out of chicken sh!t. 4 ohm speakers? Matters not, you need juice!  You need quality upstream or any speaker just doesn't show what it can do. Listen to these speakers playing Ry Cooder's I Flathead, JJ Cale's Troubador (vinyl please), or Amy Helm's Didn't it Rain, at a reasonable volume and tell me these speakers are less than excellent and we will discuss them further. Or not.  Again, my experience, my room, my ears.  Just be sure to compare apples with apples before making blanket statements.  These are room filling, nut jarring, smooth, detailed, soundstage champs that excell at making music. Plus they don't cost (used) a king's ransom, don't punish your ears, and won't break your back handling them.   Phenomenal product. 

markmendenhall said "Phenomenal product"...

I couldn’t agree more!!! Feed them Kobe steak..not generic hot dogs..and you will then understand what all the fuss is about. Great speakers...period!!!