In addition to break-in, I hope you realize that the Pot is not linear, it is very exponential. You will need to turn it up quite a bit before it starts to really get loud. Then again, it appears to me that you are nearly at the end of the Pot's travel.
Are you sure there isn't headroom? What about the sound tells you it has no headroom? Is it measurements? Not doubting you, only trying to learn for myself.
thanks
Yes, I had read on Headfi where a helpful post explained how an exponential volume pot works. Nevertheless I can tell you that I could listen to the Arya at max volume on the SA-1 with little discomfort while I can't go past 2pm on the V200 even for a couple of seconds.
Someone posted that it can drive also the Susvara and I just can't believe that it's true, at least based on the unit in my possession.
My experience is:
1. Arya - volume 90-95% (5 o'clock)
2. AdX5000 - 80-85% (4 o'clock)
3. CLEAR - 75% (3.30)
4. Q701 - 90-95% (same as Arya !!)
5. ELEGIA - 60% (2 o'clock)
6. DT990 600 ohm - 95-100% (yes, I hit the max volume and it was listenable)
7. DT1990 - 75-80%
In short the V200 offers more "reassuring" performance when it comes to drive very demanding headphones. I do not own an A90 but I suspect that whoever is after power as first priority might be served better by that. Perhaps also by the A30.
With that said, the SA-1 is much cheaper than a brand new V200 and if you are after a smoother sound is a purchase that makes sense. It is indeed closer to a tube sound without the distortion. If I were to keep it, I would use it with both my Focal.