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


triskadecaphobic
I found a relevant thread I started a few years ago. The tech specs I listed there show no mismatch:

"Rondo red:
Recommended load impedance 10-200 Ohm

Linn linto:
The input impedance measured 165 ohms at 1kHz

http://www.ortofon.com/products/cartridges/moving-coil/mc-rondo-series/mc-rondo-red
Compatible impedance and best impedance for optimal frequency response are not the same thing.

Did you follow the link I provided on optimal impedance matching?
I read it carefully. I still do not understand the difference between the two.
Please explain this and if possible a step by step procedure of what needs to be added ? Resistor in parallel to right and left ? What values ?
Maybe you're expecting more out of your table than it's capable of delivering.  I had a Rega Planar 3.  I returned it the next day.  Bought my first VPI table instead.  

There are plenty of good-sounding tables out there without having to settle for a Rega.
This is the link to read.

http://www.extremephono.com/Loading.htm

The circuit would typically be an R-C in series and that is placed between the +/- at the input to the amp (or in the amp). 


Most cartridges today into a higher impedance load (the Linn is not "high", but not low either), will have a bump in the high frequencies and a bit of a dip below that.  That is going to make them sound bright. Changing your cartridge is not going to fix the issue, at least not guaranteed. It could be better, or it could be worse.  

I can't tell you the exact value since I don't have your cartridge and amp.  Maybe Ortofon could help?  They may be able to provide some guidance on loading for a flat frequency response.