Class A 30 Watt Amps: Are they enough to drive my book shelfs?


Currently looking at buying a Pass Labs XA 30.5 to drive my Kef 201/2 speakers which are rated at 86 DB sensitivity.  Is this a bad move?
puffbojie
tubes, transistors, transformers, capacitors, ... are all relative to the rated amount of power within certain specs. All are sized to achieve a price point. Other components are designed to deal with ... heat. If an amp truly could produce more power within specs, certainly the manufacturer would publish that capacity. It ain't so. Measured distortion prevents a larger rating.

reserve power not only for instantaneous bursts, move a low efficiency woofer forward, of low and enough power to control the woofer, and, have enough reserve to make repeated instantaneous bursts. Many subs have servo control to assist with the tight control to avoid distortion.

volume controls, preamp components, pushed to high output is not sensible to me. A lifetime of too much heat from high output is also not sensible to me. pushing tubes hard, why?

Play Mickey Hart,, even at mid volume, serious amounts of power is repeatedly needed, serious amounts of control of the woofer is repeatedly needed. 


I've used the XA 30.5 with ATC 85db sensitivity speakers and there was no problem going loud. This amp can put out much more than 30 watts.
More than enough driving my Harbeth 7es-3 (86 db  1w/1m)  with my XA30.5 . As previous post just mentioned and I forgot--the amp goes into A/B at a certain point delivering more than 30 watts and I dont generally need to go past that marker on the dial which shows when leaving hard core class A.
I use a Pass Labs X150.5 on Vandersteen Model 5s.  The meter has never moved out of class A.  Its sounds plenty loud for me.  Dance club loud, no.  But plenty loud for home use.
I ran my Pass xa30.5 with a pair of KEF reference 107s with zero headroom issues. They were 90 dB efficiency and presented a 4ohm impedance.

I honestly think your bookshelves will be fine with the 30.5
Its a marvelous amp and hopefully the last one i ever buy.