When I had a similar situation a few years ago I spoke to Amprepairservices.com and the chap was very helpful and prices were reasonable.
That was for an Arcam Alpha 6+ amp to be repaired (scratchy pots and a hiss that built up over time), together with a few tweaks to improve performance as he put it.
Think he said about £200 all in, which was great as it sounded very nice other than the problems.
In the end I ended up with a new amp (Arcam SR250) as I went a different way with my hifi but I wouldn’t think twice about recommending the chap purely from his knowledge and just being a nice guy.
In a roundabout way, I’m suggesting that if you like the sound you have and the A60 does all you need, I think you’ll need to spend a bit to better it, so I’d be inclined to get it serviced and potentially ‘upgraded’ at the same time.