Amps for Sasha


Thinking of the Pass Lab X350.5 or X260.5 as they're about the same price. Heard the class A INT30 is also a good match. Any comments?
hifinuts
I doubt that the Pass Labs INT-30A will be able to drive the Sasha's bass to satisfying levels. The Sashas have a dip down to 1.8ohms around 80Hz. From John Atkinson's measurements section:

On the other hand, the Sasha's plot of impedance magnitude and electrical phase (fig.1) reveals the speaker to be a demanding load for the partnering amplifier to drive. Not only does the impedance drop below 4 ohms for most of the lower midrange and upper bass, with a minimum value of 2 ohms at 86Hz, but there is also an amplifier-unfriendly combination of 3 ohms and –43° phase angle at 61Hz.

Here's a link to the Stereophile review: http://www.stereophile.com/floorloudspeakers/wilson_audio_sasha_wp_loudspeaker/index.html

My sense is the tonal balance will be tipped up towards the upper mids and treble if you drive them with the INT-30A. The other PASS amps you list should be able to drive them satisfactorily. Whether they are a good sonic match is another question.
I'd take the John Atkinson numbers from that review with a grain of salt as far as their delivering insight to what works well with the Sasha. The Wilson guys, as well as other reviewers, are apt to tell you 'listen first - then consider measurements'. For that matter, consider Dudley's comments based on listening with his Shindo gear. Room size and acoustics will also be factors.

Not that the test numbers are inaccurate for the test Atkinson did in the context he did it, however they don't tell us how the speakers sound or interact with different amplifiers. As far as I know Atkinson only uses a solid state amp for his measurements - does anyone recall his saying what is that amp?

Traditionally Atkinson has been somewhat er, uh, 'rigid' when it comes to matching amps and speakers. If you read past reviews of other Wilson speakers he tends to claim they require high power solid state amps to drive them. But, if you look at the amps Wilson chooses to show with, it has not been uncommon to find them paired with, for example, lower wattage Audio Research or Lamm tube gear. Also consider that Wilson speaker impedance plots will have dips in the upper frequencies - consider what happens there with solid state gear that increases voltage when impedance goes down.

I'm not suggesting that John Atkinson's opinion should be ignored - far from it and I'm glad we have his measurements - but my own experience along with reports from different reviewers and folks whose ears I trust have taught me the Sashas and other Wilson speakers can deliver very satisfying results when driven by amplifiers outside Atkinson's parameters. In the case of Sasha it probably is a good idea to pay attention to Wilson's minimum wattage suggestions.

I'll suggest dropping a line to Wilson customer service (which is excellent btw). They and their dealers do a lot of Sasha in-room setups and I'll bet they have direct experience with the amps you mention.
I've heard them with the BAT 600se and the sound was very good. Also heard them with the Mcintosh 301 monoblocks (tube). Also good but the BAT amps had something special going on with the Sashas.
No offense, but I know a person who is running them beautifully with a pair of 30 SET tube amps. On paper you would think so, but numbers only tell half the story
Different strokes for different folks. I know of examples of people driving them with 100+wpc SS amps and not being happy with the bass performance they are getting. As with all things if you can audition the amp/speaker combo you are contemplating, that is the best way to make any purchase decision. Good luck.
I would definetively take the stereophile measurements seriously ,i consider it a magazine with a more scientific aproach ,the rest is more screaming about whats the next best thing " or what is the bestëver" or "what is absolutely the best"
With a impedance drop to 2 ohm at 86 herz i would definetively take a stable amp with good currentdelivery at that impedance, to make sure you hair a drumsolo on high volume without strain when you want it
I personally heard them FLY on two occasions.
With the Krell 402, and with a Plinius SA Ref.
I've heard them sing very nicely with ARC.
Your better off with the XA series. I run XA 100.5's with WP 8's. Great match.
I have the Sasha and I can tell you that the Nagra PL-L and the Ayre MX-R is a very nice combination. I have been told that the Nagra VPA is also quite nice if you want to go all tube. I have also heard Naim with the Sasha and it was very nice.
The VTL 450 III would be very nice, especially in triode mod.
I recently heard them with a Boulder 1060, definately worth a listen. That set up will haunt me for a long time.
I heard Sasha3 at AXPONA last month, one of the best sounds in the show with XA30.5. That amp easily doubles into 4 ohms. Sasha isn't that tough a load (3ohms.) I have also heard it with AR Ref 110, very emotionally communicative, and ballsy. Magnificent on orchestral music.
I would definetively take the stereophile measurements seriously ,i consider it a magazine with a more scientific aproach

Andromedaaudio, take a look at this link:
http://www.atma-sphere.com/papers/paradigm_paper2.html

Stereophile does not recognize the Power Paradigm, even though we see it all around us in high end audio today. IMO, their failure to take this into account invalidates some of Atkinson's comments, although I often (but not always) find his measurements useful. IOW, Power Paradigm technologies will not always look good using Voltage Paradigm measurements!

The Wilson speakers are an example of Power Paradigm technology. This is why the Sasha is easy to drive with tube amplifiers that otherwise might have grave difficulties with that low impedance in the bass.
Loudspeakers designed under this paradigm are said to be 'voltage driven', as they expect the amplifier driving them will produce constant voltage despite the speaker's variable load impedance

Why should a certain speaker (expect to) be designed according to this paradigm , is that a design feature which they had in mind ,as its not a must for a crossover to function as far as i know ?
i personally try to design a speaker with the highest impedance in the crossover as possible just to avoid problems , but not by using artificial networks .
If the sasha is a very tube amp friendly load ,i dont know personally.
i do know of certain speakers that have certain networks to accomplish a artificial smooth/higher imp.

I see it more in the way that ,if a certain voltage level doesnt drop with a heavier load(lower speaker imp ) than it is automatically shown that that amp is capable of instant greater current delivery meaning better loudspeaker unit control (important for dynamic swings for example) .
What also plays a rol is i think the musical taste of somebody , big/loud dynamic music sucks up more current than a quiet jazz combo for example ( i think that i have not measured that)
Does it hurt to have a big powersupply /constant voltage/ power doubling amplifier to lets say 2 ohms, i think absolutely not .

greeetz hj
I want add one more thing , a lot off loudspeakerunits that are used by manufacturers today (I know some improve/make there own) have increased efficiency due to their design and neodymium magnets drive for example , this will usually lift the overal efficiency of the speaker and with that also the need for high power /high current (transistor)amps .
And become more tube friendly
" and with that also -decreased- the need for high power / high current amps "
Many exhibitors used Sasha to demo their gears at CES this year but the one the left me amazed was the famous Krell's Dan Agostino. His new Dan Agostinos mono blocks and the Sasha were an amazing match. Previously, I listened to a pair of Sofia driven by VAC monos but this Sasha/Dan Agostino amps beat it by miles and some.

QN
I see it more in the way that ,if a certain voltage level doesnt drop with a heavier load(lower speaker imp ) than it is automatically shown that that amp is capable of instant greater current delivery meaning better loudspeaker unit control (important for dynamic swings for example) .
What also plays a rol is i think the musical taste of somebody , big/loud dynamic music sucks up more current than a quiet jazz combo for example ( i think that i have not measured that)
Does it hurt to have a big powersupply /constant voltage/ power doubling amplifier to lets say 2 ohms, i think absolutely not.

Andromedaaudio, what you are describing here is the Voltage Paradigm. I think you do well to keep the impedances higher as the speaker becomes less critical of the speaker cable. And you are right, it makes it more 'tube friendly', but there is more to it than that. Tubes don't double their power as the load is cut in half, but that is not the same as saying they they can't make really good, natural bass (they can). That is why if you want the speaker to be 'tube friendly', its a good idea to have a tube amp handy.