The “best upgrade” for you will be the best you can buy within your budget.
By buying used, you’re getting great value. There is a lot of used Naim amps and preamps about, and prices vary widely. If you are patient and get a good understanding of market prices, you’ll know a good deal when you see one.
My advice is to be patient and go as ‘high up’ the ladder as you can. Me - I would be aiming at say a 282 and a 250, not less. There are no shortages of these on the market.
The 250 is a regulated design that will start to perform noticeably below normal when it needs a service. Certainly something to be aware of at 10 years. The 200 may last a little longer. Any power amp over 15 years old, I would definitely be getting it a recap.
All I’ll say is be sure to demo these components before buying as you may not get on with them. The 202/200 were very forgettable to me and not worth the trouble of going separates. Maybe if you’re in a small room with some bookshelf speakers they’re more worthwhile. Otherwise I’d be looking to make a bigger jump from the SU. A 272/250DR wouldn’t be too bad of a lift at current s/h prices, and you can add a PS later if you want. Better SQ than your listed options. Also, since you have a SU perhaps you’ve already done the work-arounds for lossless integration, TIDAL/Qobuz/Internet Raido. Also, make sure you optimize your network, you can squeeze a lot of SQ out of the SU by optimizing your network using a switch or two, proper ethernet cables, etc. Actually, I’ll ditto what HH said above, good options there too.
Yes. I haven’t always been an advocate of special power cords, but the PowerLine works. It usually brings out lucidity, clarity, dynamics. Something that might ‘help’ a SuperUniti.
One more queston,
How many EUR is the recap? Just about…
I have no idea, you would need to ask your local Naim dealer or service agent.
Anyone else might be know?
Where are you based? I may ask a good friend who owns and runs the only authorized Naim servicing lab in Italy.
From Hungary… Not need now… just I try to get some information what are my opportunities