AR SP8 mk2 high output volume

@atmasphere , that is what I said, or....what I meant. A volume control / switcher, straight, without a gain stage ( passive ) to the power amp section. If I was not clear, I apologize.

@Georgehifi I will not make decisions because they are necessary to respect the Nelson Pass Bible. In hifi there are many factors at play and I believe that Nelson Pass will be compassionate if in my house I am satisfied with a result that alters one of his commandments, and that according to other colleagues are saying, and according to what I am listening it is perfectly audible and satisfactory by the reasons being said. I respect your reasoning, but It is much easier than going to a technician and if we add everything that includes the sum of factors that influence the final result, it would be necessary to be very sure that this Nelson Pass mandate prevails over all other factors and responds to a perfectly palpable injury from my chair.
if this AR + Puresound A30 set won’t sound very good to my ears, I wouldn’t have worried about excess gain at all. thanks really for your help

@Georgehifi I will not make decisions because they are necessary to respect the Nelson Pass Bible.

I'm saying that the easiest cheapest way out of your high gain predicament, with "gods" recommendation to back it up.
 
Unless you want to have sound quality compromises, by having two volume pots in the siganl path or voltage dividers ( Rothwell attenuators)  at the inputs of the A30 both causing impedance mismatching problems.
 
But seeing this AR pre seems to be some sort of cherished attachment, and your not keen to dump it
Then the A30 needs to be mod'ed properly, input switching and volume potentiometer disconnection, with 100kohm loading resistor to take it's place to ground and a 50% gain lowering, all done by a tech with view on stability still, is the only other way out!!

You can't have your cake and eat it too. So suck it up and do one or the other. because your just going around in circles unless you do.

Cheers George

Good to know the A30 volume pot does not degrade the signal when set lower than full. I learned something. 

@georgehifi Do you think I'm lying when I say that I like what I hear when I connect the AR? It's very easy for me to use the A30 as a built-in amplifier and keep the AR as a collector's item. Can I also buy a Dac with variable output or does this also contradict Nelson's Bible?

What is evident is that there is a discrepancy between people who, like you, are interested in helping and I am grateful. You affirm that using two potentiometers compromises quality but does not say to what extent it compromises it, or what should I hear anomalous as a consequence of that.
I remind you that the origin of this problem is that Guy Sergeant, the manufacturer of the A30, has put in his instruction book that this integrated amplifier can function as an EXCELLENT power amp, just by setting the potentiometer of the device to the maximum. This gives me to understand that if there is any compromise with the quality of the signal, it may be minimal.
Grateful for your help, but not for repeating the same thing many times, it becomes more true.