Rega Planar 3 : Heavily upgraded yet produces a sound that I don't like

I have the Rega Planar 3 turntable for 30 years now. It had an original everything including a 100$ nottingham analogue cartridge/stylus.
Sound was not bad but pretty basic....
A few years ago I started upgrading it. I did all the upgrades together and the result is... not good. The sound is very accurate but it is too bright, there is almost no Bass and drums have no attack whatsoever.
I can't eliminate where the problem is because all upgrades are irreversible.
I know that the Ortofon Rondo Red has a very bright sound but still...

Here is a list of the upgrades :

1. ISOkinetik ISOvert Rega Tonearm VTA Adjustment Kit

https://www.analogueseduction.net/isokinetik-upgrades-and-parts/isokinetik-isovert-rega-tonearm-vta-adjustment-kit.html

2. Cardas Litz purple phono cable

3. ISOkinetik Tonearm Low CG weight

https://www.analogueseduction.net/isokinetik-upgrades-and-parts/isokinetik-isoweight.html

4. Ortofon Rondo Red Cartridge/stylus

5 Linn Linto phono pre amp (an old but outstanding piece which has a cult following).

6. I use Rega Elicit Apmplifer