System advice

Thanks to ALL of you for your kind and helpful replies!

Truth be told, for last 2 years I almost stopped listening to the music because of lack of understanding what happened wrong and how to change it. You encouraged me enough to try again. :)

I finally decided to get rid of Naim amp & preamp and come back for a while to an old Arcam amp & preamp. Let's see how it sounds now to my ears. There's another question to ask as I've been thinking about a tubed DAC like Lampizator Baltic, but I have no idea if it will be a good match up with Monitor Audio + Arcam, but I also don't know if Arcam will be replaced with something else... Should I buy Lampi and then try to match up a amp to it or the other way around?

@akg_ca thanks, I'll definitely try some of the amps you mentioned.

@zlone specs of my speakers - https://www.monitoraudio.com/en/support/past-products/platinum-ii/platinum-pl100-ii/#specs

@larryi honestly I didn't know before that many people don't like Naim amps. my problem was I asked for suggestions on.. Naim forum. What possibly could go wrong? :-)

@erik_squires yeah, definitely going off was a mistake. I'm not sure though if Arcam and Monitor Audio are extremely neutral - honestly, it's not what I remember from the past, but XLO cables are considered to be fast and detailed so maybe that made a nice combo? 

@knotscott it's too bright and too cold, even bass sounds harsh. It lacks of sweetness and warmth. Speaker placement is not an issue, I moved to another house and nothing changed :)

Go back to your old system. It was foolish to listen to that salesman's advice! What he wanted you to buy was a waste of your money! He was a predator looking to earn a commission by selling you that more expensive Naim system.

The Lampizator DAC will look pretty but compared to a Benchmark DAC it is way overpriced!

Well the problem was introduced with addition of Naim components. Don’t change speakers or cables. I would recommend focusing on the amplifier first. Amp is absolutely critical. Figure out the budget and start researching. For time being put your Arcam stuff back in and list your Naim stack on the used market.
That’s what I would do. 

Should I buy Lampi and then try to match up a amp to it or the other way around?

Since you liked the sound before with the CD5/Arcam combo I’d try to get that sound back in place first and then try a DAC, which could well provide significant improvements.  Which DAC will depend on what specific improvements you’re looking for at that point, but I’d get the base system squared away first before throwing another variable into the mix.