Class A preamp or Class A amp

Hi, what is the best and most efficent way to bias an audio signal? Class A preamp with a class B amp or vice versa? Thanks
NOt exactly sure what your question is but the preamp will have the most effect on the sound.
Where do you live? I live in Phoenix. My Aleph 2s are Class A & I don't use them in the summer. I don't enjoy music with my heat pump cycling on & off......
A Class A pre-amp is not as big an issue - much less heat generated.....
It is the total design of the product. Some great products are actually Class A-B. Cello was an example of great A-B.

It is much easier for a company to make a preamp class A, than the amp.

Go by the sound, not the specs!

(I use only Krell class A.)
"On the other hand" class "A" and class "B" may refer to two completely different things:
Class A class B refering to mode of operation IN class A (full signal always on) or class B 1/2 wave signal with switching)
Class "A" as in Stereophile ratings: class A... class B etc.
The mode of operation is less important than how well it is implemented, so no real answer there...
As far as the rating sort of class...
A better pre or a better amp? that is open to debate, but I personally would opt for a better pre than amp. if I had to choose in that manner.
Thanks for your responses. As for Elizabeth, I was talking about the mode of operation. I have read that Class B or even AB has switching distortion in the transistor. In contrast, I have read that a well-built Class B can have two halves of the audio signal almost perfectly match just like it was operating in Class A.
The only class B stuff with "high end" aspirations I know of is Naim. Not my cup of tea.
Remember that class A runs very hot.
And that most amps running in so called class A really run in class A only up to so many watts, when they glide into class AB.
A "pure" class A preamp is pretty common, and you have a lot of choices... because that is where it really counts, in the low-level signals
So I would say the preamp class A
So the answer is Class A preamp and Class A/B amp that stays in Class A for at least several watts. I use my pair of Alephs in the summer as they're suspended from the cooler ceiling joists just under the speakers, both to keep them and me cool!
Transistors need enough bias current to 'Wake them up' into their linear operating range. Higher bias levels will generate more heat and use more electricity. Since heat is the enemy of long life a cooler design may be wise.
I personally feel that your rig will be as good as the weakest link in the music signal chain. Two wrongs do *not* make a right in this hobby. To get the best possible sound, the "offending" component needs to removed totally & another better performing unit placed in there instead. There is no doubt that class-A pre & class-A power yields the most linear sound (I will not comment on 1 implementation of class-A vs. another) & if you can afford it as a *total* solution, then get that. Total solution includes electric bill for AC power & cooling. I have found that if the designer has decided to make a class-A amp right from the get-go then heat sinking is very well thought of rather than being an after-thought. Still, good ventilation is a requirement by the end-user.
Next best would be class-AB that are biased towards class-A for their initial watts such as Pass, Symphonic Line, Odyssey Stratos just to name a few I'm familiar with.
I quite certain that each piece in the music signal chain affects the overall sound. So, you decide where you want to compromise but don't let anyone tell you one piece has more or less effect than the other!