Amps for Sasha

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.