Preamp tubes or amp tubes will give more change?

In most all-tube integrated amps, the splitter/inverter tube (and often the gain multiplier tube(s) as well) are eliminated since the preamp section is wired directly into the amp section. So what you will usually see (at minimum) are a couple of preamp section tubes, a couple of driver tubes and then the power tubes.

The Cronus appears to be set up this way, except it has the one extra 12AU7 which (I'm guessing) is for the phono preamplifier section, a nice feature.
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all tube circuits are not created equal. i have auditioned tube components which don't responsd to tube changes. thus, there is no way to predict which component will be morre affected by tube changes.

i don't agree that small signal tubes have more of an affect upon the sound of an amplifier. i have noted , using both vtl 120 amp, consonance amp and mapletree amp, that changing the output tubes have as much or more of an impact on the sound than changing the driver tubes.

i don't agree that small signal tubes have more of an affect upon the sound of an amplifier. i have noted , using both vtl 120 amp, consonance amp and mapletree amp, that changing the output tubes have as much or more of an impact on the sound than changing the driver tubes.

First, I said the *gain multiplier tubes*, not "small signal tubes" or "driver tubes."
Second, did you do a controlled experiment with each of those three amps - comparing the effects of changing one group of tubes at a time (gain, driver, power) while holding the other two groups constant?
I stand by my statement; and further, point to a basic electonic reality, which is that where the signal undergoes the most processing (the 'gain' stage, in the case of amplifiers) is where it stands to be most affected by the hardware. YMMV ;-)
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Thanks all for sharing your experiences. I will try some input tubes first and output tubes later.

Thanks Nsgarch for your detailed post for me to understand more on the structure of tube amp.