AN Niobium versus Tantalum resistors?

your results with full Z-foils mirror my own. Ideally I use a mixture of Z-foils and Takman metals, with a few Caddock MK132 (very full, bold and assertive) and Shinkoh tants (musical and finely textured) thrown in for flavour.

The MK132‘s are very good at balancing the  Z-foils in circuit.

I will try a Niobioum on the input position for 500 hrs

Takman metal film are the best value for money out there. Shinkohs do not sound better in all locations.

Niobium prices set new standards for resistors…..ouch….

listen for yourself, and don‘t buy into the boutiques sound better everywhere trap. Work out where you need to spend the money

absolutely brilliant as the shunt resistor in a stepped attenuator. If you put them everywhere the effect can be a bit OTT. YMMV

I am passing on naked resistors due to a point Takman brought up in their papers.. which is that naked is going to be a victim of induced current, which means magnetism.. this is the same reason Furutech has special grounding and demag in their connectors. Those competing magnetic fields are a no-no if you are going for rock bottom noise. Which I am in this application. Also... Takman pointed out the bodies can be a point to add vibration countermeasures.

not trying something on the basis of what you read in a paper published by a competitor, is rather unsound practice IMHO. Until you have heard a naked Vishay z foil replace another resistor in the direct signal path you can not begin to comprehend what they can do.

As I stated before, they are not a panacea, and must be used judiciously as their utter transparency can prove too ruthless and become overtly clinical when used exclusively.

 these won't supply your needs

excluding compoents from consideration based on pure speculation made on the basis of what you read is rather unwise IMHO.

Caddock MK132 have the signature the OP is looking for.  These are discontinued, however their replacements the MK232 should fit the bill as they share the same construction and have undergone only minor changes for Rohs compliance.

doesnt sound like too many people have tried Niobium

think the price has scared a lot of people away. Would be most interested for you to post your findings 

 in the end you are the chef and season to your own taste..

well. it appears you have taken the plunge. Will be intrigued when you report back..

glad the Z-foils worked out for you at the input, they really are transparent. Yes, filling an entire system with them can be a bit overwhelming, and too much of a good thing.

combo of Takman Rey, Rex and Z foils

I too have found that a very pleasing blend can be made from a combination of these, and at a pretty reasonable cost..