Pass XA200.8 Review - Fun measurements

My previous post should have said in the first line, “relatively low level of corrective feedback”.  That said, the very low measured output impedance, including cable, of 0.03 ohms suggests a very healthy degree of corrective feedback, although there may be other explanations for this.  Would explain the very limited open-loop bandwidth and consequent increase in high frequency THD to 1% at 20K into an eight ohm load.  Still, the proof of the pudding is in the eating, as the saying goes.

@erik_squires 

I think it depends on set up and taste as to what works best. My point is you don’t need to spend a fortune on power amplification to get a warm tubey sound. SS power amps that try to emulate tubes like McIntosh are going to colour everything coming through them. The beauty of a tube preamp is you can play your DAC directly or through the tube preamp - just a couple of interconnect connections....

I think that the Pass X series is their best all around amp. I have the new Pass XP-22 preamp and the Pass X350.8 amp. They produce a very detailed and somewhat tube like sound with excellent sound stage. 
While this system is expensive, you are paying for excellent sound, reliability and product support that is second to none. In fact I had Mark at Reno Hi Fi steer me away from their class A amps because of their lower power and high heat output. I run this system with an 
Allnic H 7000 phono amp (tubes) and achieved an excellent result. 
The trick with a Pas system is to have a tube phono amp like a Herron,
Audio Research or Allnic.

Finally, to me, tube power amps are a real hassle to maintain. Their reliability is far below that of a Pass which is built to last and maintain its sound level. Tubes (especially power tubes) deteriorate over time.
And they have reliability issues because of poor QC in the factories that produce them. 

 

@shadorne - Agreed. 

30 years ago I made a purchase primarily based on measurements and it turned out to be something I was not happy with. Since that time only purchase based on how it sounds, but will look at specifications for component compatibility.