AN Niobium versus Tantalum resistors?

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.

I’ve had the Niobiums in a couple days, also replacing Takman Metal. Knowing the improvement the Z’s did, initially I’m not super impressed.

I had hoped for the radically low noise/linearity of Kaisei, but these are more on the carbon/tant vibe of "smoothness". Dynamics a touch reduced over any metal I’ve used, a slight compressor effect. Resolution and noise floor is pretty good, not amazing. These are the "closest" to metal that I’ve heard, coming from something that is not metal. But still, when you switch to techno music, the roundness and inaccuracy is apparent. Even solo acoustic feels like I lost the dynamics and fatigues me a little with the "evenness". I’m going to try Z-foil in this 2nd position and I think that will work for me here. If you find your metal resistors too sharp and clear but hate carbon, these are probably what you are looking for. They are musically very nice..but I can’t live without the dynamics I had.

I think its definitely a matter of finding the right seasoning for your application.

How long are you leaving the resistors in place? I would assume there would be at least some break-in involved.

Typically I use the full 300 hours my Furutech solder needs, so its painfully slow. Audionote recommended 100hrs for their resistors. In fact, the Niobium are making some progress..so I’ll report back after a couple hundred hours. But for example, EL caps and metal resistors begin too thin and clinical in my experience, very slowly opening up and feeling natural. These have been the reverse.

Likely I will try the Z-Foils in place, because I suspect the Niobium are going to sound very similar...the price point is identical.In the studio I want maximum transparency.

But for my hi-fi, I want relax... today I added the Niobiums there, coupling the VCap ODAM’s to the El84 cathode, replacing some metal foil. I like the results already. The most brittle recordings of ancient instruments and 1970’s Japanese jazz which sounds like a tin can are totally listenable, which the metal always had trouble with and the carbon turned into nice but flat boredom.

UPDATE:

I was concerned the Niobiums were too tubey and compressed sounding, so I swapped all the resistors to Z-Foil. There was instant gratification of low noise and high resolution, but after several hundred hours they did sound thin and there was an extremely "metallic" felt-texture. Tingy, metallic, pingy. Acoustic guitars and flutes and especially vocals were metallic to the point of sounding like my loudspeakers became tin cans. It was unenjoyable for everything but showing off slick sounding techno music.

In this case, I would prefer Takman or a mix of Z and Takman, because Takman have crispy and gross highs, but are FAR more musical overall than Z foils. 

However..

I put back in the Niobiums which had 150 hours on them, after AN reassured me I should continue burning them in.

Now at over 300 hours, I can say the sound is fantastic. They became tighter from bass to treble, with no slowness or compression, but much more music comes through than Z-foils. The felt-texture which began woody and waxy now is more like "felt" (think of the felt hitting a metal string in a piano), which is very low fatigue. Acoustic guitars sound natural, bass is warm, highs contain a ton of information - tambourines and cymbals are rich and natural. Imaging is easily as precise as the Z-foils, but with an analog feeling and not metallic.. overall a perfect resistor! Just keep in mind they really do take well over 200 hours!

While I was concerned at their ’tubeyness" at first and combined them with Z-foils, I am ordering more for the circuit and think I can go full-Niobium. Just bear in mind its a very long burn-in.