They do need very high current and also a lot of high quality wattage, you want the amp to be the conductor of the push pull twin woofers............
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There are many recent inquiries about the suitability of the Pass Labs XA-30.5 and XA-60.5 amplifiers for use on speakers that most agree require more power than these amps provide.
It seems like "hope against hope" that somehow the actual power delivered by these amps is going to exceed the manufacturer's power rating, thus allowing people to afford a lower powered Pass Labs amp than they actually require.
Owners of these speakers may find that if they listen at low to moderate levels in small rooms that these amps will provide sufficient power, however in many cases the amps won't be sufficient for realistic (translate to "live") listening levels in medium to large rooms.
Keep in mind that a VERY important factor in how much power you need is the dynamic range of the music you listen to (meaning the DIFFERENCE in volume between the loudest notes and the softest notes).
One of the most demanding kinds of music in that respect is classical symphony orchestra, if it is well recorded with minimal compression. If you set the volume control to produce modest volume levels at your listening position of say 70db on soft-to-medium passages, brief dynamic peaks on orchestral crescendos, bass drum beats, etc., can easily exceed 100db. 100db requires 1000 times as much power from the amplifier as 70db.
On the other hand, if you listen to typical highly compressed rock music, which may have a dynamic range of only a few db, and you listen at modest volume levels, you will need far less power. For instance, an 85db peak only requires 1/32th as much power as a 100db peak.
If you love the amp, and it doesn't quite work with the speakers (you may be fine), it is certainly an amp worth building a system around, it is a great SS amp. It was extraordinairy with my Merlin VSM-MXes, but still preferred an OTL with the speaker. I agree with TVAD observations about the desire to have these XA.5s provide enough power, I would say that they perform as they do have more power than their ratings would suggest, but there is a reason for the higher powered versions.
I agree with the speakers being the starting place for building a system as it defines the basic sound and then sets the parameters for the amps that can best drive the speakers. Some speakers narrow the choices considerably, especially if your preference is to use tubes, and low powered tubes at that.
Disclaimer: I am a dealer for Pass and Proac, however if you like Totem speakers why not go right to Proac. Similar look, sound better (I find Proac's more transparent and dyamic though) similar price and are easily driven with the XA30.5. Email me if you want more info, but I use Proacs and the XA30.5 for my main display and it is magical.
Almost all Proacs can be driven by little as 10 watts or sometimes less.
*If you love the amp, and it doesn't quite work with the speakers, it is (still) a great SS amp. It was extraordinairy with my Merlin VSM-MXes (Pubul57)*
Merlin's are a great suggestion IMO, esp. w/a lower-power power amp. I had TSM's & loved them (w/in their limits). I love my Mani-2's now, but probably wouldn't try them w/a power amp w/o enough watts/current.
Nothing wrong with matching speakers to an amp that you really like.....I say keep the Pass amp, get speakers that work well with them.....
I completely disagree with Audiofeil (not looking to start an argument, but just want to display a different viewpoint). There are some tangible traits that can only be had in certain amplification no matter what is hooked up before or after it. No matter what you change in the stream you sometimes cannot reach that particular sound that the amplifier can give. Just my opinion.
For example, the Totem Mani2s are relentlessly power hungry, running a Pass X250.5 or better will yield great results, but the X250.5 will never have the particular organic sonics of the XA series. Thus many folks find speakers to fit a particular amp to achieve that organic sound. Again, just want to show a different opinion.
Fatcataudio, I do understand what you are saying, and it certainly is a consideration, there are certain amplifiers that have a certain kind of performance that is very appealing, I think the Pass XA30.5 wo uld be a very good example, SETs and OTLs would be another, as they have unique qualites as amplifiers, and I agree with you that you could start there and find a speaker that matches well. On the other hand, I agree with Bill that the speaker is likely to be the component that has the greatest influence on the basic sound of a system, and the variations between speakers seem to me to be of a higher order than between amplification ans digital sources of similar quality and price points. For that reason, I still think that finding the speaker you love should come first and then find the amplification for it. Not that you couldn't end up at the same place the other way around, but I think getting the speaker right first will tend to lead you to a more satisfying solution. But there is more than one way to go about it. I knew I wanted tube friendly speakers so that guided my search, but the Merlins than opened up the possibility of going the OTL route or amps with 30 or so watts. If I had fallen in love with Thiels, I could not own the amps I do, not the even the great XA30.5.